Super rugby = Super effort
Posted by Boertjie - 10/03/10 at 01:03 pm under Laws and Technical IssuesModern rugby has been likened to the human body being subjected to a series of car crashes and now there is scientific evidence to back it up, writes DAN RETIEF.
SuperRugby
I was staggered recently by the amazing information contained in an article penned by Ross Tucker, an expert in sports physiology, in a Press release from sports drink company Powerade.
Tucker, who holds a PhD in exercise physiology from the UCT Faculty of Health Sciences, has been commissioned by the Minister of Sport to draw up South Africa’s high performance plan for Olympic sports and consults to the SA Sevens team.
Having long been fascinated by the supreme effort required of the players in Super 14 rugby Tucker’s opening line caught my eye: “The Vodacom Super 14 competition puts elite rugby players through one of the toughest tests in the game – with up to 15 maximum efforts over 16 weeks, often across 10 time-zones…”
Anyone who has ever travelled a long way east from South Africa will tell you about the debilitating, disorientating effect of jet lag but imagine what it must be like while constantly being mugged by thugs from the penal colony or rough Kiwi manual labourers?
Demands accurately quantified
Well, this is how tough it actually is. According to Ross Tucker recent developments in technology have allowed the physiological demands of the game to be accurately quantified using GPS devices*, giving us information on distance covered, running speed, heart rate, intensity of player impacts (g-force), and energy expended during matches.
*The GPS devices are attached to a vest worn under the players’ jerseys. The chip is placed between the shoulder blades, where it is unlikely to be damaged and can pick up a player’s heart rate – the signal being sent to a computer at the side of the field which stores the data.
These studies, conducted in England and Wales, have shown the following:
► A backline player will experience about 120 ‘impacts’ per match – an impact is any involvement in a tackle, ruck/maul, or collision with the ground. Not surprisingly, forwards are involved in more impacts than backline players, with about 300 per match. Of these, 70 have a g-force greater than 8g, and the majority of impacts, somewhat surprisingly, come in the second half (65% compared to 35%).
► In terms of running, backline players can expect to cover between 7 and 7.5 km a match, while forwards cover between 5 and 7km, depending on their playing position (loose forwards covering the most distance). About 70% of the match is spent standing or walking, 25% is spent jogging, and 5% running at sprinting speeds. This means that for every second spent running, players will rest or move slowly for about 5 seconds.
► However, the real challenge lies in the number of times players have to change speeds, either accelerating or decelerating for short periods. The average ‘sprint’ is 20 metres long, and it happens 30 times a match, while fast jogging for 20m happens 90 times a match. In total, there are shifts in speed approximately 750 times per player per match, or once every 3 to 4 seconds. The challenge in terms of conditioning is to prepare players for this constant shifting of pace and direction.
► Forwards spend more time doing very high intensity exercise (finally there’s proof!), and less time walking or standing than backline players (65% of the match for forwards, compared to 75% for backs).
This is explained by the forwards having more ‘static exertion’ periods – scrums, rucking and mauling. The result is that overall, even though backs do more running during a match; they actually do less total work than forwards. For example, in an 80-minute match, a loose forward can expect to burn about 2000 kCal, compared to 1700 kCal for backline players.
This is 25% higher than what has been measured for professional soccer players. By way of comparison, a 90kg man running a half-marathon (21km) burns about the same amount of energy as a Super 14 player every weekend!
► Finally, the physiological load is actually greater in the second half of matches. Players run further in the second half, with more accelerations and short sprints, and there are twice as many impacts in the second half.
Last 30 minutes tell!
More time is also spent doing high-intensity running and less time walking in the second half of matches, especially for forwards, which says that play is more continuous in the second half. It’s perhaps not surprising then that scorelines often remain tight for 50 minutes before opening up – the last 30 minutes is where the physiology begins to tell!
The equipment being used to monitor players was first developed in Australia’s AFL and Tucker says he is looking forward to studies being done comparing the southern hemisphere to the northern hemisphere and perhaps providing conclusive proof to the contention that “the Super 14 is the hardest rugby competition in the world.”
Still not convinced or impressed? Try this. Go out on the lawn. Stand upright. Chest out. Now lie down. Now stand up. Now lie down again. Now stand up. Now lie down again, perhaps get the dog to jump on you… okay keep going – you only have 79 minutes and 50 seconds to go!
March 10th, 2010 at 1:40 pm
Moerse interessant.
March 10th, 2010 at 1:42 pm
Maar 8 g’s?
Ek dog mens pass uit hier by 5 of 6 g’s?
March 10th, 2010 at 2:46 pm
Reply to manvanstaal @ 1:42 pm:
I think the pass out is only when the g’s are for a couple of seconds
March 10th, 2010 at 2:56 pm
Reply to Ollie @ 2:46 pm: I see…
March 10th, 2010 at 3:07 pm
“forwards are involved in more impacts than backline players, with about 300 per match”
I have long questioned the ‘modern’ tackle stats in rugby… for example… Schalk Burger is alleged to have made 16 tackles in 60 minutes of rugby last weekend… which means he made one tackle roughly every four minutes… which is patently absurd…
in post-game analysis a ‘high’ tackle-count for a team is in the region of 80 tackles… meaning that all 15 players between them only manage one tackle per minute…! again… patently absurd…
so I’ve asked before how do ‘they’ define a tackle that counts as one… because the numbers just don’t add up…
it has been suggested that the ball is not in play all the time and therefore the tackles are made in a much shorter time… a reasonable explanation… but still leaves me wondering…
now if a forward has 300 ‘crashes’… many of which are tackles… per game… it must mean a guy like Schalk is getting tackled some 285 times a match for the 15 tackles that he actually makes on other players…!!
sure… maybe not every crach is a tackle but the 70 8g plus crashes are either a player tackling or being tackled…
I’m now more convinced than ever that the tackle stats they quote are simply plain wrong…
anyone have any ideas…?
anyone connected with DSTV and or the rugby stat guys to get some answers or an explanation…?
would really appreciate it…
thanks!
March 10th, 2010 at 3:09 pm
Baie interessant.
IS dit akuraat?
70% of match is spend standing or walking
thus 30% “in action” = 24 minute
Of the 24 minutes in action – on average – you have
1 – 88% / 20 minutes jogging – forward will find it difficult to “jog” faster than 5 minutes per km = 4 km
that leaves 12% / 4 minutes to run 3 to 3.5 km – I don’t think so mate – that will give you 2 minutes to run just 1.5km – Olympic Gold record time – bwahahahaahaha
4 minutes per km is friggin motoring it – still only gives you 5 km.
that leaves 4 minutes to run 2 to 2.5 – that gives you 2 minutes per 1000 meters that is 120 seconds for 1000 meters that is 12 seconds for 20/25 x 100 meters in 80 minutes
on top of the friggin stiff 5 km at 4 minute/km pace – maybe only a Habana will run that in tokse on thick grass !!!
2 – 30 x 20 meter sprints = 600 meters
3 – 90 x 20 fast jog = 1.8 km
that in total is 2.6 km sprinting and jogging – where is the other 4.4km – 4.9 km ???????????
by now I have lost complete – believe – in the STATS
March 10th, 2010 at 3:10 pm
Reply to UFO @ 3:07 pm: I can tell you but then I’d have to kill you.
March 10th, 2010 at 3:11 pm
Reply to The Brand @ 3:09 pm: Hulle het seker die chips ge-activate voor hulle op die bus geklim het games toe.
March 10th, 2010 at 3:13 pm
Klink vir my n inpact is enige stampie wat jy kry.
Wonder of as jy jou voete hard stamp of dit sal registreer as n impact.
March 10th, 2010 at 3:14 pm
Reply to manvanstaal @ 3:10 pm:
as long as i know the truth before i die…!!
March 10th, 2010 at 3:15 pm
Of as n spanmaat jou n ‘pat on the back’ gee en se ‘Kom boys!’ of dit ook tel.
March 10th, 2010 at 3:15 pm
Reply to manvanstaal @ 3:13 pm:
not at 8g’s… surely…?
March 10th, 2010 at 3:19 pm
Reply to UFO @ 3:15 pm:
only when you captain kicks your arse to get on with it
March 10th, 2010 at 3:19 pm
Reply to UFO @ 3:15 pm: A tackle could probably register more than on 8g reading.
Collisions with the tackled player and then with the ground or maybe other players.
March 10th, 2010 at 3:21 pm
Ek dink as die kaptein skreeu: ‘Pressure boys, pressure!’ dan is dit so 3g’s vir almal wat nader as een meter van hom af staan.
Dis nou as hy n voorspeler is.
March 10th, 2010 at 3:24 pm
Reply to manvanstaal @ 3:19 pm:
yeah… all probable…
but I reckon there’s a clear… and massive… discrepency between the tackle stats and the GPS stats presented here… I’d be inclined to trust the science over some bloke counting tackles between swigging his Windhoek and dragging on his Marlboro and noshing his biltong…
March 10th, 2010 at 3:33 pm
Reply to JT @ 3:19 pm:
that’s some kick…!!
March 10th, 2010 at 3:33 pm
Reply to UFO @ 3:24 pm: For sure.
March 10th, 2010 at 3:51 pm
Myself so bietjie ge-educate.
n G kan positive of negative wees.
Op n rugby veld reken ek ons praat van negative g.
So ons se Habana suiker teen 36km/h in die middel van die veld af.
Dus beweeg hy 10m/s.
So nou word hy reg van voor getackle en gaan van 10m/s tot nul in 0.1 sekondes.
So hy decelerate teen 10/0.1 = 100m/s.
En dit is 100/9.8 = 10.2 g’s
March 10th, 2010 at 4:09 pm
Reply to manvanstaal @ 3:51 pm:
Dankie
neem steeds nie my ??? tekens weg nie
in Reply to The Brand @ 3:09 pm: hierbo
Daarmee sê ek nie alles is KAK nie – maak my net moerig as fiete in feitelike artikel makaar weerspreek
March 10th, 2010 at 4:11 pm
bwahahahaha – blindesambok – fiete in feitelike artikel – bwahahahaa
March 10th, 2010 at 4:19 pm
Reply to manvanstaal @ 3:51 pm:
you’re a smarter man than me, working that out…
so… if he’s not running at full speed… or a forward running slower… would mean most of those 8g-plus collisions are tackles…???
which means each player should be involved in 70 or so tackles per game as the tackler or as the tacklee (for want of a better word…)
which still means the tackle stats are majorly wrong…???
or am I missing something here and I am as dof as people keep telling me…
March 10th, 2010 at 4:22 pm
Reply to UFO @ 4:19 pm:
What will the G’s be at the engage at scrum time? Both front rows hitting in on each other…
March 10th, 2010 at 4:25 pm
Reply to JT @ 4:22 pm:
from stand-still… surely can’t be ashigh as 8g’s…?
surely…???
Dan needs to ask these guys to give some more info on what various collisions rate as… so that these stats are not blind…
March 10th, 2010 at 4:30 pm
Reply to The Brand @ 4:09 pm: Jou vrae is te moeilik.
March 10th, 2010 at 4:35 pm
Reply to UFO @ 4:19 pm: No idea. Still trying to wrap my head around this g business.
BTW 36km/h = 100m in 10sec.
Don’t think many, if any, reach that on a rugby field.
March 10th, 2010 at 4:36 pm
But then again my calc’s assume only one object is moving. No idea what the impact is for say player A moving at 20km/h getting hit from the side by player B moving at 17km/h.
I need to lie down.
March 10th, 2010 at 4:39 pm
Reply to manvanstaal @ 4:36 pm:
but reckon it’s fair to say that the 8g crunches are from tackles and the sudden stops generated by them…???
March 10th, 2010 at 4:40 pm
Obviously the quicker you come to a standstill the more g’s.
March 10th, 2010 at 4:42 pm
It seems sports PHDs comes in Lucky Packets. Anybody can see that the numbers do not add up.
8g is absurd.
2000kCals is absurd too.
March 10th, 2010 at 4:42 pm
Reply to UFO @ 4:39 pm: If I were a betting man I’d bet good money the 8g’s are tackles.
March 10th, 2010 at 4:44 pm
The 8g number is most probably the result of the built in positional inaccuracy in GPS.
March 10th, 2010 at 4:46 pm
This was on TV over here lately.
Shows how impacts add up…Mind you, the results would have probably differed a bit had a gladiator like oh I dunno…Todd Clever been in the experiment, but interesting nonetheless.
http://www.youtube.com/watch?v=W7tGY-VDx3o
March 10th, 2010 at 4:48 pm
Lyk my die g force besigheid is complicated.
Blykbaar as ek jou a snotklap gee, ervaar jy heel moontlik 100de g’s op jou wang (of waarever my palm val) vir n kort tydperk maar overall rig dit nie veel skade aan nie.
March 10th, 2010 at 4:50 pm
Lyk my die killer is die tyd wat jy die g forces ervaar.
March 10th, 2010 at 5:11 pm
Reply to manvanstaal @ 4:50 pm:
Not sure but think time would certainly figure into it.
A few weekends ago I got drunker than 10 indians and in the morning I know I expeirienced some serious G forces for a several hour duration (:
March 10th, 2010 at 5:22 pm
have you guys seen that Time Warp programme where they show a boxer getting klapped in the face…?
in slomo it looks like the guys whole face slides around his skull… or in other words the guy’s skull rotates behind the guy’s face… as the skull moves instantly and the flesh moves later and then catches up and overtakes the bone… amazing to see…
would be interesting to see the impact of a rugby tackle in that super slomo… 20000-plus frames per second…!
March 10th, 2010 at 5:28 pm
Reply to manvanstaal @ 4:35 pm:
You are all thinking about hits from people running – what about the hits from a swinging arm or scrum engage or shoulder hit. For that split secound, for that short distance 20cm for example surely the shoulder or arm can reach much higher velocity than a man running!? Thus the contact on the area must be taken into context, no?
March 10th, 2010 at 5:31 pm
Reply to JT @ 5:28 pm:
I really have no reference here so don’t know what I’m talking about…
i’m just s’posing…
my point is there’s something wrong with the tackle stats…
March 10th, 2010 at 5:33 pm
Reply to UFO @ 5:31 pm:
I agree that 300 knocks seem high but we need to know what the define as a hit. What they define as a tackle, what they define as “inactive” or active for that matter. This article to make sense should be at least 50 pages long to explain where the information/data comes from.
March 10th, 2010 at 6:27 pm
Reply to JT @ 5:28 pm: For sure. Plus those gadgets are between their shoulder blades.
I know you get those g-force stickers for parcels to see if the poskantoor played soccer with your parcel.
Might get me some of them and stick a few on me to see if I experience any g’s at work.
March 10th, 2010 at 6:29 pm
Reply to Americano @ 5:11 pm: Interesting.
Been so drunk before my bed and room were spinning in different directions. Would have loved to be able to measure the g’s then.
March 10th, 2010 at 6:34 pm
I will put R1000 on the fact that 80% of coaches in professional rugby dont give a shit about these stats.
March 10th, 2010 at 6:41 pm
And for the record, I am really enjoying Dan’s stuff since he decided to concentrate on rugby alone and leave TV – he talks more sense now.
between him and Brenden Nel, my two favourite writers.
March 10th, 2010 at 6:52 pm
Reply to manvanstaal @ 3:51 pm:
So ons se Habana suiker teen 36km/h in die middel van die veld af.
——
Ek dink nie ‘n mens kan so
vinnig hol nie – nader aan
so 30 km/h.
Jy’s mos slim:
9.0 sek. vir 100 meter
= km/h
March 10th, 2010 at 7:17 pm
Reply to Boertjie @ 6:52 pm:
Olifant se top spoed is dan 40 km/h
March 10th, 2010 at 7:25 pm
Reply to The Brand @ 7:17 pm:
Ja, ek het deurmekaar geraak
met m.p.u. en km/h.
Google:
America’s Maurice Greene is the fastest recorded running human being. During the 9.79 seconds it took him to set a world record for the 100 meters, he reached a top speed of 43.45kph/27mph .
Ek vergeet soms daar is omtrent NIKS
wat jy NIE op Google kan kry nie.
March 10th, 2010 at 7:57 pm
Amazing – menslikheid storie.
Vriend van my Duo – se dogtertjie het gewas op die brein en is nou al so twee weke in Hospitaal – het twee operasies al gehad – ter voorbereiding en GROTE lê om die draai.
Vandag dievolgende:
Duo Oosthuizen: Vandag, meer as ander dae mag ek se EK IS TROTS OM N BLOU BUL TE WEES!!!!!!!. Morne Steyn nommer 10 van die Bulle en Bokke (vir die wat nie weet nie. Ek weet daar is n hele paar dames op my FB.) het vir Ankia gebel om haar geluk met haar verjaarsdag toe te wens en sterkte met die operasie. Kyk daai dogtertjie smile van… oor tot oor en het van alle probleme vergeet vir daai oomblik. BAIE DANKIE MORNE!!!!!See More
3 hours ago · Comment · LikeUnlike
2 people like this.
Duo Oosthuizen:
Oja en Ouma wat dit alles gereel het. Thanks Ma!!!!!!!
3 hours ago
Adriaan Schroeder:
Weet jy dit was nou nice van morne,hy is ook n mens,mens met n hart van goud !!!Ek ook trots om n Bul te wees !!!!
2 hours ago
Thea Bruce:
Wow! Hy’s my hero ook en ek is ook trots om ‘n Bul te wees. Go Bulle!
51 minutes ago
Benita Van Loggerenberg:
Op die blou . . .
My bloed bly blou
44 minutes ago
March 10th, 2010 at 8:12 pm
This is why we need heroes.
Pity some dont deserve the title.
Well done Morne.
March 10th, 2010 at 8:13 pm
On that note, I am out for the night.
Sleep tight Ankia.
March 10th, 2010 at 9:06 pm
Reply to Boertjie @ 6:52 pm: Meer lui as slim rerig. Ek het 36km/h gekies want dit maak die somme makliker.
36km/h = 10m per sekonde.
March 10th, 2010 at 9:53 pm
Sekerlik is dit Usain Bolt wat die vinnigste is?
March 10th, 2010 at 10:18 pm
Ag fok watse kak is Americano se video…
You et a bunch of Los Angeles amateurs to tee off and measure their tackle strength against an NFL professional quarterback…
What kak
If they wanted to be serious they should have taken say Bakkies Botha or Butch James and gotten them to tackle somone …. then i am certain they would have gotten frigging close to the 4000lb/sq inch exertion…
March 10th, 2010 at 10:25 pm
Reply to DavidS @ 9:53 pm:
Jip, lyk my daai inskrywing
is effens verouderd.
Bolt = 9.58 sek.
Op 60 meter beweeg hy seker
naby aan 50 km/h.
March 11th, 2010 at 2:26 am
Reply to manvanstaal @ 1:42 pm:
Dit hang nie net af van die hoeveelhied G’s nie, maar ook die rigting van die G’s. Pilots het gewoonlik die uitpass probleem omdat die positiewe G’s 99.9% “opwaarts” is in relation tot die liggaam. Dus die bloed vloei uit die brein na die onder en die resultaat is verloor van bewussyn.
Dit is hoekom hulle seker oefeninge doen en G suits dra, wat die effek teenwerk.
F1 drivers word ook onderwerp aan hoe G syfers, maar dit is meesatl negatiewe G’s wanneer hulle rem en laterale G’s as hulle om ‘n draai gaan. As hy nie fiks genoeg is of sy nekspiere sterk genoeg geoefen het nie, sal hy sy nek seer maak, maar nie sommer uitpass nie.
Die onderskeid is dus, ten opsigte van liggaams posisie, vertikale of horisontale G’s. horisontaal sal nie sommer dat jy uitpass nie. Vertikaal is die probleem.
Reply to JT @ 5:33 pm:
300 hits is not that high, I would have expected more.
Just think of it by breaking it down.
If a player tackles another:
1 hit in the tackle, possibly another from the tackled player’s arm or leg swinging and hitting the tackler, another hitting the ground, depending on the speed a “bounce” counting as 1.
That is 4
Tackelr get up and contest the ball:
hit by opposition to clean him, hit by support, hit by second oppo in ruck
That is another 3 – the more that join the more hits.
Line out take and setting up the maul:
“hit” by support, hit by oppo to oppose, every oppo joining maul will register hit, every support joining will record a hit
That could result in up to 15 hits in one movement.
Setup 5 mauls = 75 hits
Make 10 tackles = 40 hits
Say 60 rucks per game and player is involved in 50% with 6 players involved = 5 hits per ruck = 150 hits
That is already 265 being conservative in assumptions. Add the scrums, etc and it can easily top 300 hits.
March 11th, 2010 at 8:25 am
Reply to DavidS @ 10:18 pm:
Sorry just to add
In rugby the tackler is usually hitting someone who is also running so just there you can double the pounds per sq inch in the hit….
This test sucked IMO
March 11th, 2010 at 9:39 am
Reply to DavidS @ 8:25 am:
I won’t say it sucked. Maybe just classify it in the useless info category
March 11th, 2010 at 9:40 am
Hi folks
Good discussion on the piece, I was sent the link by Dan Retief and I thought I’d post some thoughts in response to the column.
First, regarding the g-force, remember that the value you measure is dependent on how the measurement is made. For example, in the NFL, they have sensors in the helmet, so they are able to measure the impact forces and accelerations of the head during a tackle. Their numbers are astronomical – they regularly record g-forces of more than 100g during matches and practices!
however, because that is a measurement made at the head, and the impact is extremely short, the acceleration is large. it’s different when a fighter pilot is banking a plane at supersonic speeds and the force is a centrifugal one applied to the whole body for maybe 10 seconds.
So in the GPS study that I wrote about, the measurement is of the player’s torso (because the GPS sensor is located between the shoulder blades) and it’s measuring accelerations. So when a player speeds up from jog to a sprint, that’s an acceleration. if they sprint to a breakdown and suddenly stop, that’s even larger. When they’re hit in a tackle, that’s the biggest acceleration of the whole body, but it’s very short lasting. no less severe, but much shorter, I hope that makes sense.
So now, to put into context, when they measured 300 impacts, they’re defining impacts as changes in acceleration that correspond to g-forces of 5 or higher. Interestingly, they did look at all g-forces, and then you get 700 ‘impacts’ per game, but these are not true impacts – they include sprinting and then stopping and so forth.
Those 300 “impacts” are therefore made up of tackles, arrivals at breakdowns, cleaning, any contact, impacts with the ground, and very, very rapid changes in speed.
That hopefully address UFOs question earlier. A good one – I also wonder about “tackle counts” (bearing in mind that tackles and impacts are not the same thing). Would make interesting stats. I have some, I’ll find them.
Ok, regarding the next issue, raised by The Brand, I have a meeting to get to, so I’ll be back in an hour or so with some thoughts!
Cheers
Ross
March 11th, 2010 at 9:54 am
Hi Ross,
Thanks for that. As always the science must be view in isolation AND collectively to get to some kind of assumption. BUT like all science there are few constants, thus each and every situation to be analysed with the hope that over time one can make more accurate, never complete, assumptions from a mountain of data.
As they say certainty is a big word when it comes to science.
March 11th, 2010 at 9:57 am
Reply to Ross Tucker @ 9:40 am:
And the 700 impacts make more sense for me, but with the specs of the test the 300 is more understandable.
March 11th, 2010 at 10:03 am
Reply to The Brand @ 3:09 pm:
U19 we use to do 100m sprints for 20 minutes each and every training session. Split into 5 groups of 4, the first group would go and as soon as they reach the opposite 22 the 2nd group would start. Group 1 rest on the opposite tryline until the last group passes the 22 in front of them and it starts all over.
So I do not think it is impossible to do that over the course of 80 minutes. You are doing it maybe 20m/40m at a time.
March 11th, 2010 at 10:12 am
Reply to The Brand @ 3:09 pm:
Lets say there are 20 lineouts per game. That will result in a backline player having to sprint between 10 and 15m either in defense or attack.
Every scrum it can be between 5 & 10 m
Good up & under will travel 30m and needs to be chased. Every tactical kick needs to be chased by attacking team or chased back by defending team.
The more I think about this, the more sense it makes. One needs to break it down to the basics. First impression is just to think of a game “globally”, not of every play that forms part of the game.
March 11th, 2010 at 10:23 am
Reply to Ross Tucker @ 9:40 am:
Thanks Ross, Interesting stuff. Looking forward to your answer of Brand’s questions.
March 11th, 2010 at 10:27 am
Reply to Ross Tucker @ 9:40 am: Thanks Ross. Exactly what I’ve been trying to tell them all along.
March 11th, 2010 at 10:29 am
Reply to manvanstaal @ 10:27 am:
Hehehehe
March 11th, 2010 at 10:30 am
Reply to manvanstaal @ 10:27 am:
You have to give our cousins from up North more time to digest information if not given in illustrations!!!
March 11th, 2010 at 10:33 am
Reply to Ross Tucker @ 9:40 am:
thanks Ross…
fascinating stuff…
more like it would be great!!
March 11th, 2010 at 10:52 am
Reply to Ross Tucker @ 9:40 am:
Before I read ANYTHING you said here at RW
the following
for making the time and doing the effort to be here!!!
March 11th, 2010 at 10:54 am
Reply to Morné @ 10:30 am:
So that is why you took so long to comment.
March 11th, 2010 at 10:57 am
Reply to Deon @ 10:54 am:
Hehehe,
Nah I did not need to say anything.
Finally people are getting an appreciation for the science that goes into rugby – been preaching it for years now.
Could add nothing to what Ross has said.
Other than my comment that I reckon 80% of coaches don’t give a shit about information like this…
March 11th, 2010 at 10:58 am
Reply to Morné @ 10:57 am:
Or don’t understand it.
March 11th, 2010 at 11:00 am
Reply to Deon @ 10:58 am:
Perhaps more accurate that yes!
March 11th, 2010 at 11:01 am
Reply to Ross Tucker @ 9:40 am:
Thanks for providing – background – for information.
I am wondering if they indeed – correlated their GPS data with actual video-footage.
Therefore being able to not only have “generalised” data on acceleration and deceleration – but – identified moments of impact – to use for comparison.
Them gold are in them details
March 11th, 2010 at 11:02 am
Reply to Morné @ 10:57 am:
I think too many caoches are either:
a. Olde school and put off by technology
b. Don’t have the time away from the trainingfield (or budget to get somebody to do it) to be able to put the technology to use
c. Don’t know how to sell new methodologies to the players. Don’t under estimate what “power” the players have subconciously over what training techniques they will accept.
d: Any combination of the above
March 11th, 2010 at 11:03 am
Reply to The Brand @ 11:01 am:
Aye, it not that you have the facts but how you use them
March 11th, 2010 at 11:10 am
BTW, which of you buggers are Dan, or is he an eternal roofkijker?
March 11th, 2010 at 11:16 am
Reply to Ollie @ 11:10 am:
Hehehe
March 11th, 2010 at 11:21 am
Reply to Ollie @ 11:02 am:
Regarding point c., this probably won’t be a problem for pro-coached just you average club coach and lower
March 11th, 2010 at 11:24 am
Reply to Ollie @ 11:02 am:
You would know to a large extent as you have coached yourself.
Science does not dictate or should not dictate how we play the game, and stats should always be used and viewed in isolation or as ‘indicators’.
But it is vital that we understand the physical demands of rugby and ‘what actually happens on the field’.
Data like this revolutionised training overall as well as position-specific training.
Like we say so many times it is not the quantity that is important, but the quality that is vitally important.
Modern rugby gives you a limited period in which to train and prepare, those who use this time most effectively will end up being the most effective when it comes to game time.
I could never understand as a youngster why the fatties were expected to keep up with us backs in fitness and conditioning exercises when clearly, they did not need to.
Nor was I interested in bench pressing 140kg’s because quite simply, it did not apply to me as a player.
I have never believed in singular fitness and conditioning training as a group, but always split my players up in accordance to the 6 combinations you find in a rugby team.
This reaches even further.
When I concentrated on defensive skills the different types of tackling techniques differed from player to player, or combination to combination quite simply for the fact that over 80% of tackles will be made in specific instances and places on the field only, where a certain technique is vital not only as a means to stop opposition players from crossing the advantage line, but also because defensive techniques also differs where it is more likely for you to turn a ball over, and who those players are 80% of the time that will be in a position to do this.
Of course the basics of the game should never be forgotten, and please do not confuse players with data or statistics, but a simple explanation like;
“Okay Jannie, because you play center 80% of your first time tackles will be made from phase 3 onwards. 60% of those will also be drift defensive tackles so rather than concentrate on your leg drive power in driving a tackled player back, we need to work on your technique to get to your feet quickly to possibly turn over the ball as this is the area we are most likely to do this given how many support players will be there in the first 3 seconds of the tackle.”
(As an example).
Apart from time on the road, pool sessions and recovery sessions, I have always been in favour of splitting my players into groups to concentrate on individual conditioning and fitness and technique.
March 11th, 2010 at 11:29 am
Reply to Morné @ 11:24 am:
Looks like I am going to have to put that all into practice again. I’m out of action with injury until the end of the season and so will be assisting the coach and doing video work.
I’ll have to dustoff all the notes collected the last few years
March 11th, 2010 at 11:32 am
Reply to Ollie @ 11:29 am:
It is a thankless job but someone has to do it!!!
March 11th, 2010 at 11:44 am
Reply to Morné @ 11:32 am:
not as bad as refereeing!
March 11th, 2010 at 11:53 am
Reply to Morné @ 11:24 am:
THIS gets me even more excited about the coaching web-resource
March 11th, 2010 at 11:57 am
Reply to The Brand @ 11:01 am:
That would be an excellent way of doing it…!!
March 11th, 2010 at 12:01 pm
Reply to Morné @ 11:24 am:
Morné…? You GOTTA get back into coaching… and at a higher level…
HTF I don’t know… but your thinking is what we sadly lack in SA rugby…
March 11th, 2010 at 12:44 pm
Ok, I’m back.
I see much discussion about the philosophy behind these stats, and that many coaches would deem them irrelevant. I have some things to add to that, but I promised I’d first respond to Brand’s earlier point, so here goes:
The actual study had a table of the distances covered in each zone, but unfortunately the format of the article didn’t lend itself to having a table there, and also the article couldn’t get out of hand length-wise, so I had to leave things out, and break the numbers down, and perhaps the confusion is as a result of that.
So, here’s the table, in more detail:
A backline player covers 2802 m in walking and slow jogging per match. Time-wise, that’s about 60 minutes, assuming a slow walking or jogging speed for say 30 minutes, and standing for 30 minutes (ball out of play for example – remember that ball in play time is only about 50 minutes, though i think with the ELVs, it might have increased. Call it 55 min).
1956 m are covered slow jogging, so that’s 12 minutes (speed of 6min/km)
670 m covered in “cruising” – so call that 3 minutes (speed of 13 km/hour)
978 m covered in “striding” – just under 4 minutes
292 m in high intensity running, which is less than 1 minute
524 m covered in sprinting – so that’s 60 seconds as well (speed over 20km/hour, which is not really sprinting, in my opinion, because the marathon world record average speed is just under 21km/hour, but I guess the line has to be drawn somewhere!)
The sprinting and fast running legs are made up of about 30 surges, each lasting about 20m, giving the close to 600m
So the total time now works out to 81 minutes, and total distance just about 7km. For the forwards, the distances and time spent standing and walking is lower, and they also sprint less. But the “middle zones” are up which is why they cover more distance.
If I look at Brand’s initial calculations, it didn’t take into account that there are a range of jogging speeds (my fault – i didn’t include it in the article), and so the 70% of the time that is “inactive” actually also contributes to distance covered. I think that accounts for most of it?
The next issue is whether this information contributes value.
A lot of time, science DOESN’T, and I believe that we (being scientists, if I may speak on behalf of science for a moment) are often responsible for our own ‘lack of appreciation’.
I’ve seen studies on performance in rugby that end up making the ground-breaking conclusion that “the team that wins is the one that scores the most points”! Seriously, I get embarrassed, because sometimes people come with all the stats and analysis and end up saying nothing much. So I understand why coaches rely on instinct ahead of data…sometimes.
I’m obviously biased, but i believe this kind of information can be very valuable. It was kind of ‘lost’ in the piece, but to me, the most important finding of the research is that impacts, distances, speeds and number all INCREASE in the second half of matches.
Now, I’ll concede that maybe coaches have known this for years, but certainly, my impression has always been that players slow down, that the game opens up and so there’d be fewer impacts, less distance covered.
turns out that the opposite is true. The implications are numerous. one is that it highlights how vital fitness becomes, but we all knew that already. Now it’s tangible. Second, it allows coaches to perhaps identify who needs to come off based on objective data (an idea we have played with for Sevens, but the game is too quick there to analyse in “real time), and third, it emphasises the value of intelligent substitutions.
Also, it may be an important factor that alters how training is done. The thing that I’ve learned about coaches is that the good ones tend to naturally do what the science shows after the fact. There is a ‘functional intelligence’ that science can’t match, and coaches often teach science what to do. But there is enormous value in knowledge, particularly in the right hands.
For example, upcoming articles will describe how the team that wins close matches tends to kick the ball more, tackle more, pass less etc. All of which points to the fact that if you have the ball, you might be at a disadvantage! But it doesn’t mean that you should kick your ball away – information is powerful, but equally misleading if not used in the right context. So a lot of it is just “fluff”, of interest, but given how tight the margins are, information is one place where you find advantages. the best coaches are the ones who process information most effectively, and for them, I agree, much of the physiology and the performance analysis will merely validate what they already knew. There has to be value in that too, by the way…
As a learning tool, however, it becomes crucial!
Anyway, my 2 cents’ worth.
Ciao
Ross
March 11th, 2010 at 12:54 pm
Thanks Ross, your input is much appreciated. Any idea where we can find the results of more studies like this one?
March 11th, 2010 at 12:55 pm
Reply to Ross Tucker @ 12:44 pm:
Ross I am more satisfied that you are here and participating.
Thanks for giving the detailed breakdown.
NOW do you understand why you have to share any future articles with us at RW ???
HERE you have the fantastic opportunity to give ALL the details you want
March 11th, 2010 at 12:58 pm
Thanks again Ross…
really interesting stuff…
could also count against making substitutions as the new players will be performing at the rate of the other players at the beginning of the match… in other words… players subbed on are behind the pace and struggle to catch up which is why so often the game falls apart after the subs are made…
March 11th, 2010 at 12:59 pm
Thanks Ross. Much appreciated.
March 11th, 2010 at 12:59 pm
Ross would this also impact the type of fitness exercises the players would do seeing as it appears the game becomes MORE intense as it progresses?
This would also logically impact your … sorry…. use of impact players…. perhaps their best place then is EARLIER in the game…
March 11th, 2010 at 1:03 pm
Reply to Ross Tucker @ 12:44 pm:
Ross – I think you just might have stumbled into your “home-from-home” here at RW.
We are all maybe just “mug-punters” to use a phrase of Bryce in Australia.
But I also believe you have gained valuable insights purely from how we have “analysed” your information in Dan’s article.
he he he – lastly join the club in convincing coaches to the benefits in what you have to offer, that they don’t see “immediately”
Did I find you information valuable?
Bet you life on it !!!
Looking forward to you next article and participation !!!
March 11th, 2010 at 1:03 pm
Reply to Ross Tucker @ 12:44 pm:
You are about 4 years too late for this site or any site mate!
But seriously, all of what you say is true, knowledge is one thing, application of that knowledge is something completely different.
I found this very important when you look at the game at club level, specifically if you look at your more traditional white clubs, and coloured clubs.
Now just from a physical point of view there is a massive difference between the clubs, the one (whites) are generally the heavier, bigger boys where the coloured clubs are the lighter, quicker guys on the park.
Their playing styles for this reason differs massively.
For this reason, a lot of scientific or analysis data will be important to one team specifically, but not to the other, because it does not suit that teams specific strengths.
I found the most important or first step for any coach to assess what he has first, analyse his strengths and weaknesses. Idenitfy which weaknesses can be addressed, and which can’t, plan your game plan, game plays, conditioning and practices along these lines then specific to your strengths, and areas you look to improve – both from a team perspective and from an individual perspective.
To do this effectively, knowledge and the work Ross does is vital.
Some data applies to everyone, but also, a lot of data are not as useful to one coach as it is to the next…
Ross,
The part of what you raise that the intensity picks up in the second half is massively important.
I think importantly, what would be interesting is to see for which positions specifically, there is a dramatic increase in the second half, and which positions stays the same throughout or decline.
This will aid massively in planning for ‘clever’ substitutions which most of us on this site, has highlighted as one of our greatest weaknesses, even at national level.
March 11th, 2010 at 1:04 pm
Reply to UFO @ 12:58 pm:
Great new angle on subs – isn’t it ?
March 11th, 2010 at 1:08 pm
Reply to The Brand @ 1:04 pm:
definately – maybe it is better trying inexperienced new guys in the beginning for 20-30min and bring on the hardened experienced guys just before the 2nd half for the rest of the game to close it out..
Can you get away with this in a game? Biggest issue is injuries, what do you do if you already subbed your “rookie” and the senior player gets injured? Something to look at and think about. :thumbup:
March 11th, 2010 at 1:11 pm
Reply to The Brand @ 1:04 pm:
for sure bud…! rewrites conventional wisdom without doubt…
maybe as DavidS says… maybe better earlier… player plays flat out for first half hour or so then goes off…
March 11th, 2010 at 1:11 pm
Reply to JT @ 1:08 pm:
Seeing which players specifically has a huge increase in collissions will aid this a lot.
You can cover probables much easier.
March 11th, 2010 at 1:12 pm
Reply to JT @ 1:08 pm:
both points are true…
very intersting choices to make…!!
March 11th, 2010 at 1:16 pm
gotta say again…
THIS is why I really like this site… other sites are purely about banter and social get-togethers…
this site is about learning for me… and that’s awesome… never too late for this old dog to learn a couple of new tricks…
great stuff…
here’s one for RW…
March 11th, 2010 at 1:29 pm
Reply to Ross Tucker @ 12:44 pm:
“the most important finding of the research is that impacts, distances, speeds and number all INCREASE in the second half of matches.”
Ross surely this then SCREAMS that the players need better and more efficient MENTAL training – to be able to increase effectively during the second half.
I am just wondering – if one breaks the second half into halves does the same apply then as well RE increase???
March 11th, 2010 at 1:30 pm
Reply to UFO @ 1:16 pm:
Thanks
March 11th, 2010 at 1:42 pm
Reply to Ross Tucker @ 12:44 pm:
There is a ‘functional intelligence’ that science can’t match, and coaches often teach science what to do. But there is enormous value in knowledge, particularly in the right hands.
========
Now if the scientists can just
separate the fluff from their
findings . . .
March 11th, 2010 at 1:44 pm
Reply to DavidS @ 1:30 pm:
no David… Thank YOU!!
you’re welcome!
March 11th, 2010 at 1:44 pm
Reply to UFO @ 1:16 pm:
Hehehe. It’s difficult with the
ERT around, but we try our best.
March 11th, 2010 at 1:48 pm
Reply to Boertjie @ 1:44 pm:
hehehe…
but seriously… this stuff from Ross is awesome… very enlightening…
and you guys are responsible for this site and platform…!!
kudos…
March 11th, 2010 at 1:53 pm
Reply to Boertjie @ 1:44 pm:
As long as Morne, Cab and the bonobo don’t rub me up the wrong way I’m quite nice…
March 11th, 2010 at 1:55 pm
March 11th, 2010 at 1:58 pm
Reply to UFO @ 1:48 pm:
Spread the word if you know
someone that shares your
interest.
We have many roofkykers but not
huge numbers of participating
bloggers, but they all make usefull contributions.
Also the ones that does the
“rubbing” of the ERT.
March 11th, 2010 at 1:58 pm
Reply to UFO @ 1:48 pm:
I think the major difference here is that most of us has been on here for years now and ‘know’ each other, hence the banter is boring because we know how to push each other’s buttons and we can quickly tell when someone is looking for kak.
In addition, most guys on here are ex or current coaches in various fields, players, people that have been involved in the media and sport in media, agents even and administrators too.
So there is a lot of collective experience floating around.
March 11th, 2010 at 1:59 pm
But it is a bit like being a doctor or a lawyer, we are all still ‘practicing’ the science of rugby.
March 11th, 2010 at 2:01 pm
Hi again
one last comment from me today – I can’t keep up with the discussion you guys are generating! (it’s great, by the way, thank you!)
Re the stats – I can’t believe the game (either the IRB or SANZAR or some other central body) haven’t made more effort to put the stats out there. I know a lot of people watch the game for other reasons, but it’s clear that many people love to delve into the second, third and fourth level of insight, which doesn’t seem to exist for most people.
I got those articles out of scientific journals, which I’m lucky to be able to do thanks to being at the University of Cape Town. But even there, the delay between when something is studied and reaches the journal is long – up to 3 years. And then it reaches only 2% of the population. I think there’d be massive value in making it more accessible (and not only for rugby).
For example (and forgive my bias towards Sevens here, but that’s the one I’m involved in), the iRB have a full-time analyst who follows the IRB Sevens Tour around and does stats. They publish those stats on their website, so everyone can see them:
http://www.irb.com/irbsevens/columnist/newsid=2036166.html#sevens+analysis+the+secrets+success
A lot of it is just descriptive, but there’s some really cool insight there. Some is excessive (we don’t use much of it, for example. We have our own guy doing analysis and video coding during matches, and Paul then provides the interpretation), but it’s a really interesting read for those who are stats-hungry.
I don’t know why a similar thing is not done for the 15-man game.
Re the conditioning, I have thought a lot about how to condition players differently knowing that the running time and resting time change in the second half. I can’t think of too much to change, to be honest. Certainly, as The Brand says, the mental side becomes crucial, and I wonder whether players are adequately conditioned in this regard, regardless of the physiological demands.
But things like decision-making, awareness, reading the game, must also change from the first to second half, and there must be ways to condition that. Also, skill levels must decline as fatigue levels rise, and it’s common practice to do skills first in a training session, then do gameplan. Maybe introducing skills at the back end of training, along with drill for decision-making, would help players learn how to think while fatigued.
obviously, it’s a tough balance, because you can’t simulate match fatigue in training, because players would very rapidly burn out and overtrain. But it’s just a thought…
Anyway, I have to run, more meetings, I hope to check in again later or tomorrow, but forgive me if I don’t!
And keep discussing – more thoughtful approaches to rugby always work!
Ross
March 11th, 2010 at 2:08 pm
Reply to Ross Tucker @ 2:01 pm:
Thanks Ross – much appreciated.
Maybe Morne can follow up re
some more regular participation
from your side.
March 11th, 2010 at 2:09 pm
Reply to Morné @ 1:58 pm:
yeah Morné… I recognise and really appreciate that… the rugby discussion is definitely at a higher more educated and rational level…
good of you guys to put up with my uneducated input…
of course, not saying there’s no room for banter… enjoy a good neanderthal scrap too from time to time…!!
March 11th, 2010 at 2:10 pm
Reply to Morné @ 1:58 pm:
hence the banter is boring
======
NEVER!
Speak for yourself!
March 11th, 2010 at 2:10 pm
Reply to Ross Tucker @ 2:01 pm:
Oh you can bet your ass Brand will latch onto this discussion now!
March 11th, 2010 at 2:12 pm
Reply to UFO @ 2:09 pm:
No such thing, like I said we are all still practicing…
Reply to Boertjie @ 2:10 pm:
but you must admit it gets too easy with ERT at times…
March 11th, 2010 at 2:13 pm
Reply to Boertjie @ 2:08 pm:
He registered! So I can contact him if he agrees.
March 11th, 2010 at 2:15 pm
Reply to Boertjie @ 1:58 pm:
I certainly will spread the word every opportunity I get…!!
March 11th, 2010 at 2:17 pm
Reply to Morné @ 2:13 pm:
Please follow up – you have
a much better rugby brain
than me.
Been thinking back about the
day we hijacked the Trompie
thread on Voldy.
And the Noot for Noot’s.
And the day we had that hillarious
banter session around cricket here
on RW – cracks, pitches, no balls,
maidens bowled over etc.
Dit sal seker te moeilik wees om
daai draad op te spoor en weer te
plaas?
March 11th, 2010 at 2:20 pm
Reply to Boertjie @ 2:17 pm:
If you can remember the title of it I can try…
Or the time when it was posted (date)?
March 11th, 2010 at 2:22 pm
Reply to Morné @ 2:20 pm:
Why not rather ask me what I
had for supper on 25.06.2007?
I think it was a hijacked thread,
so getting to it will be nigh
impossible.
March 11th, 2010 at 2:50 pm
Talking about bringing the subs on at different times, I think you guys are ASSUMING that the game picks up in the second half because the players are getting more into.
There could be other reasons a well, like an urgency from the team that is losing to get points on the board etc.
March 11th, 2010 at 2:54 pm
Reply to Ollie @ 2:50 pm:
True – one thing I have noticed is that my team usually starts very slow and “get into it” later in the game and finish strongly. There has been times the preperation was different and the guys got into it early but faded later – finding the balance is important.
March 11th, 2010 at 2:57 pm
Reply to Ollie @ 2:50 pm:
good point…
but you can only be talking about the saffa sides now… we’re the only ones who always leave it so late in the game…
now if we can bottle that and get them to play with the same sense of urgency from the first whistle…???
March 11th, 2010 at 3:09 pm
Reply to Ross Tucker @ 2:01 pm:
Thanks again Ross.
Yes sadly the – detailed – mental side in rugby is lagging
March 11th, 2010 at 3:15 pm
Reply to Ollie @ 2:50 pm:
Need better mental skills training
Reply to JT @ 2:54 pm:
Definitely need better mental skills training
Reply to UFO @ 2:57 pm:
OBVIOUSLY better mental skills training
Jokes aside – this – info – have given me another angle to use when punting my services
March 11th, 2010 at 3:17 pm
Before we completely forget.
Dan Retief
thanks for referring Ross to RW
March 11th, 2010 at 3:25 pm
Reply to The Brand @ 3:17 pm:
It is a good thing I complimented him early in the thread…
March 11th, 2010 at 3:33 pm
Reply to Morné @ 3:25 pm:
March 11th, 2010 at 4:32 pm
Reply to The Brand @ 3:09 pm:
I think some of this may be
up your alley –
Ross Tucker
http://www.sportsscientists.com
March 11th, 2010 at 6:14 pm
Reply to Boertjie @ 4:32 pm:
Check “Who Are We” on the site
- some useful background info.
March 12th, 2010 at 11:14 am
Reply to Boertjie @ 4:32 pm:
Thanks Boertjie – I have been to his site – great reading.
March 12th, 2010 at 5:06 pm
I still have a problem with measuring g-forces using a GPS receiver.
GPS only gives position and time.
You can calculate speed by using 2 position/time readings.
Acceleration (g-force) can be calculated with a minimum of 2 speed readings. That is 3 positional readings.
The problem is that GPS accuracy is about 1 to 2m. If your positional readings are 100-200m apart the speed and acceleration calculations will be accurate, since a 1-2m fault will impact the calculations by less than 1%
Impacts in rugby takes place over 1-2m for tackles and only a few centimeters when a player’s torso hit the ground.
Therefore your speed and acceleration calculations may be wildly inaccurate.
March 12th, 2010 at 5:11 pm
I have experience with this because I often run with a GPS receiver to track distance. It also helps me to find my way back to the hotel sometimes.
Distance, Time and Average Speeds are all good. Instantaneous speeds, even with filtering on, always have some absurd readings.
March 12th, 2010 at 5:19 pm
Reply to fyndraai @ 5:11 pm:
Asuming:
A. The GPS system uses satellites
B. It is only a GPS devise and not a GPS/accelerometer
March 12th, 2010 at 5:37 pm
Reply to Ollie @ 5:19 pm:
What is the difference ?
March 12th, 2010 at 6:41 pm
Satellite production is behind schedule.
March 12th, 2010 at 6:44 pm
We need a minimun of 24.
Currently we have 31.
If we go below 24 we will all be lost.
March 12th, 2010 at 6:45 pm
Dis nie grappies nie.
Don’t leave home without a map, is wat ek se.
March 12th, 2010 at 6:48 pm
Weet waantoe jy gaan voor jy gaan.
Belangriker nog, weet waar jy vandaan gekom het.
March 12th, 2010 at 8:25 pm
Reply to Ollie @ 5:19 pm:
Reading it again I see they also have heart rate and energy consumed, so it is fair to assume they had at least heart rate monitors and accelerometers in addition to the GPS.
Does anybody know how they measure energy consumed?
Is it calculated from heart rate?
“…..a loose forward can expect to burn about 2000 kCal….”
According to this a banana has 105Cal
http://caloriecount.about.com/calories-banana-i69599
So does a loose forward consume the equivalent of 20000 bananas in a game?
This cannot be correct. Or does a banana actually have 105kCal and 1 Calorie = 1kCal?
March 12th, 2010 at 8:39 pm
Reply to fyndraai @ 8:25 pm:
2000 Calories = 20 Bananas
1 Calorie = 1kCal
March 12th, 2010 at 11:11 pm
Calorie burning is quite possibly not as straightforward as we would like to think.
Human beings are extremely diverse.
Even heart rate measurement not as clear cut as the fitness ‘gurus’ would like you to believe. But close enough I suppose.
March 13th, 2010 at 11:07 am
Hi guys
Very quickly, because I’m in the airport, about to board a flight:
The g-force measurements are not made using your normal, commercially available GPS, because as fyndraai has said, that’s not quite accurate enough to track changes in speed and direction over those small distances/times.
So the device has a GPS, but it also has an accelerometer, which is able to track instant changes in speed and direction, and that’s where the measurement comes from.
Re the energy, yes, it’s calculated using a built-in heart rate monitor (so the device has 3 components – GPS, accelerometry and heart rate). Energy expenditure is relatively accurate when calculated during exercise in this way. There is of course error, but even if it was 5%, the value would still be in the same magnitude of 2000 kCal.
Ciao!
Ross
March 13th, 2010 at 11:13 am
Reply to Ross Tucker @ 11:07 am:
Thanks for clearing this also.
Ross – not too shabby – for a Cape Town boytjie
Been real impressed with your – degree – of participation here at RW.
March 13th, 2010 at 12:10 pm
Hi Brand
Thanks, good discussion to be involved in!
You’ll have to forgive me for not getting involved in the coming days – I’m away overseas and with limited access, so I may suddenly vanish!
But keep the thoughts going!
Ross