effect of excess body fat on aerobic performance on flat ground

[531Aussie]

not on hill climbing, please :)
we all know how detritmental excess weight is when going up hills. ;)

I can't find any good articles descricing the physiological effects of being, say, 15lbs overweight, when
doing (for example) a time-trial on flat ground.


thanks

[bbattle]

The fat is just dead weight so it's not doing anything to help you as muscle would. Depending upon where it's located, it could be a source of drag or subject to wind resistance. More likely, it's on your belly and back and so I don't think it would be much of a hindrance. My two cents.

[DannoXYZ]

You do have to keep it alive... ;)

[Richard Cranium]

I'm not sure what you want to know. Essentially, the excess weight increases your energy required to accelerate while on perfectly flat surfaces. I suppose, there are some additional increases in rolling resistance as well.

In theory, if you rode an extremely even speed during a TT - your weight won't cost you much.

In an unrelated area, excess body fat creates mechanical as well as possibly metabolically related inefficiencies. (thermal, blood vessel, fluid transport etc)

Two evenly-powerful cyclists? Bet on the light-weight guy.......

[Guest]

Well, with a decreased VO2 max, you're not going to be able to realize your full potential with speed, but if you could drop a few pounds, you'll be more efficient and a bit faster, regardless of whether you're on a flat road or climbing a hill.

And that fat doesn't do as much work as muscle either, like bbattle said. :p

Koffee

[531Aussie]

thanks for he replies

I'm finding it difficult to find exactly what I'm looking for on the net.

You do have to keep it alive... ;)
In an unrelated area, excess body fat creates mechanical as well as possibly metabolically related inefficiencies. (thermal, blood vessel, fluid transport etc)
....this is the kinda stuff I'm looking for.

Years ago, I remember hearing something like: the fat is a waste of blood because (as you guys suggest) it needs blood too -- it's gotta be kept alive.

[lamagy]

i dont know why but i just learned that i do better in a race with a few hills rather than a flat time trial.....i was keeping up until the 1/2 way through it and then i could keep the pace and droped down to about 17mph..

and yeah im carrying at least 45%BF.

[SSP]

Per the Calories and Watts Calculator built into my CycliStats (http://www.cyclistats.com) program, a 165 lb rider, on aero bars, riding 24 miles at 24 mph, on a dead flat course, would burn 820 calories, and require an average output of 220 watts.

Keeping everything else the same, but with a rider weighing 185 lbs, it estimates 838 calories burned, requiring 224 watts.

Of course, these are only estimates, and any amount of climbing would have a major impact on the calculation.