Obviously weight and body composition matter in both. Opinions on where it matters more? Intuitively I’d guess the longer the race, the more weight matters.
In general if you look at the top 5k runners and the top half marathoners I don’t think you’ll see much of a difference in body composition if any at all as some of them are the same guys. The two events are much more similar than they are different so they present basically the same demands on your body. I figure the longer you need to drag the extra weight around the more extra energy that will cost you leading to a comparatively worse performance over a half marathon than a 5k, but I don’t think you can really say that means it matter less in a 5k. Body composition is another story and for example if you’re more powerfully built then you will most likely perform better over a shorter race, although you might not be so good in absolute terms in that case anyway.
your assertion is correct.
My historical times are much better from 1 mile - 10k than half and full Mary. My best full Mary was at a weight where my swimming (upper body) was “not so good.”
I was, and am a “heavy” tri guy. I was a road runner before I did tri’s and I would always marvel at the skinny guys thinking that they would be so fast, some were, but, my sub 34 10k’s would leave many skinny guys minutes behind (but not the great ones, obviously). In the “old” days Australian Rob de Castella was my hero; had legs like tree trunks but went sub 2:09 marathon.
Thin to win (unfortunately that ain’t me)
Look at it this way: Which race would you rather carry a 5 lb weight? For me, it would be the 5k.
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
The longer the race, the more mileage you need in training. Heavier runners are probably less likely to be able to put in big mileage without getting injured. Obviously, there are some exceptions.
I think the answer is depends.
What kind of weight?
What kind of times?
Virtually impossible for a “heavy guy” to make the Olympic’s at either distance.
A young speedster- with a track/cross country background, who is out of shape and carting around some extra weight- can probably run a really fast 5k
A middle age triathlete- with bad running form, some excess fat and some unnecessary bike/swim muscles- might be less embarassingly slow over over 13.1
Seems there are always exceptions. Meaning if you get the right genes, you can makeup for some things like a little extra weight.
But overall, I see very few if any “heavy” folks doing real well at run races.
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The longer the race, the more mileage you need in training. Heavier runners are probably less likely to be able to put in big mileage without getting injured. Obviously, there are some exceptions.
Also the shorter the race, the larger engine of the larger runner allows him to overcome his weight, but as pounding is cumulative, as the distance gets longer the bigger guy pays a large impact force penalty with every stride which he can’t overcome over time…and as you said, to be fast at long distance you have to put in a lot of miles at high speed. For top marathoners doing a ton of “aerobic miles” at 19-20 kph (which is basically a 2:07 marathon at 20 kph) you need to be light to survive that routine and not have your body break down. The big guy is largely doomed for open marathon running, just like the small guy is doomed for NFL linebacking. Different horse for different sport.
Also you will find that the same body type that is ideal for open marathoning is not the same body type for a fast overall IM with a fast off the bike run. The lightweight runner can’t produce enough top line watts to keep up with the taller lean guy and for both riders going at say 35 kph, the energy to move the wheel is the same absolute value, and therefore a larger percent of the smaller rider’s top line watts, meaning the smaller rider will inherently do more work as a percent of body size to get to T2. Even when Welchie won Kona at around 135 lbs he was around 15 lbs too heavy at his height to be an elite marathoner.
Same % of time.
Another way of slicing it: 100m sprinters are stacked - essentially bodybuilders with excellent neuromuscular co-ordination, 200m runners less so, 800m… etc. etc. The difference at 5k/10k is obviously much smaller, but this argument-from-inspection might just hold (ie. it matters more in the 10k, ie you would prefer to carry the weight in a 5k.)
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
He does claim that, among a lot of other things but it is not at all accurate.
I think it matters more in the 13.1. Of course the pounding and distance take a toll. But I also recently saw a chart in one of the running magazines about the percentage of different muscle types that are taxed by a runner in each type of race, and the 5k uses a lot more fast twitch muscle – or at least fast twitch adds to a bigger percentage of the muscles taxed. So that extra weight adds valuable speed for a shorter distance but would just be extra weight for a longer one.
I race both distances and from my experience the weight matters a bit more in the 13.1, but it’s not that big a difference.
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
He does claim that, among a lot of other things but it is not at all accurate.
well perhaps ST people can investigate? He was using a phone app. THis phone app shows water stations, perhaps run keeper?
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
That is one hell of a claim. As a cyclist I tried to put this in context. I converted this running speed into approx. watts/kg at 5.17 and then to absolute wattage at an outrageous ~520 watts. Read somewhere that running metres/second~=~w/kg. Efficiency gives a large margin of error but holy crap that is a serious aerobic output!..or a bold lie.
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
That is one hell of a claim. As a cyclist I tried to put this in context. I converted this running speed into approx. watts/kg at 5.17 and then to absolute wattage at an outrageous ~520 watts. Read somewhere that running metres/second~=~w/kg. Efficiency gives a large margin of error but holy crap that is a serious aerobic output!..or a bold lie.
I believe he has a low 4 minute mile that is accounted for at his bodyweight
if you are following alex viada on facebook… he supposedly did a training 5k in 16:07 at over 220lb.
That is one hell of a claim. As a cyclist I tried to put this in context. I converted this running speed into approx. watts/kg at 5.17 and then to absolute wattage at an outrageous ~520 watts. Read somewhere that running metres/second~=~w/kg. Efficiency gives a large margin of error but holy crap that is a serious aerobic output!..or a bold lie.
I believe he has a low 4 minute mile that is accounted for at his bodyweight
Hmmm… I see lots of videos of him lifting. No videos of him running a 4:15 mile. And some older Athlinks results that suggest he is not doing a 16:07 5k as a training run… You’d think that someone who likes exposure and attention would want to document a 4:15 mile, especially in our age of video cameras everywhere – he’d be a Youtube sensation.
I’m a 5’8" guy who weighs around 200 pounds. I’ve placed in sprints, MOP at Olys, and I am nowhere close to placing in 1/2 IMs or longer.
I can suffer like a dog for a short race and overcome my weight but it is not a sustainable effort on longer races.