chelvel

I still don't give up... All other things equal bigger leg muscle is faster. What about HR in that case?

wphamilton

No.

Rise in heart rate correlates to the intensity of work being done. Larger muscle masses can enable increased intensity, and a higher ratio of lean muscle to fat will increase your metabolic rate, but other than that it will have little effect on your heart rate for endurance efforts.

gregf83 

Not when you have to go uphill. Heavier, stronger (than you need) muscles are just dead weight. Power/Weight ratio is key and, for a fit cyclist, increasing muscle mass will lower power/weight radio for any time period longer than 30 Seconds or so.

redlude97

no. Wiggins actually cut a ton of weight and his legs got smaller to be able to win the TdF. Why would you ignore other adaptions when they are the major component of power on the bike?

chelvel

OK. Forget it. Nothing to discuss. I will get an answer somewhere else.

Lenkearney

I AM INTIMIDATED! I am 68 (5'8" and 200 pounds) and average 14 MPH at an average hr of 134! You must be one fit dude!

Carbonfiberboy 

That's on the flat. But yes, I'm quite fit at least in summer. I also weigh 142-145 and have a fairly aero position. I also have a nice road bike with nice but inexpensive home built wheels and good tires.

OBoile

Optimal muscle size depends on the nature of the event you're participating in. Shorter events with little climbing will benefit from having (relatively) larger muscles. Consider the typical leg size for a track cyclist (like Wiggins in his early career) vs a grand tour rider (like the photo of Wiggins above).

I suspect (but don't know for sure) that overall rider weight also matters. Someone with a lot of body fat would likely benefit from larger (or more specifically stronger) muscles than someone who is quite light. The reason I suspect this is that, as others have said, strength only matters up to a certain point. I suspect that for someone who is heavier (and thus has to push harder going up a hill) that point would be higher than for a lighter rider.

Carbonfiberboy 

Huh. If that's the reason for your questions on leg size, i.e. that your legs are the size of your hands, then absolutely you'd be faster with bigger legs. When I'm fit, I have 21" thighs (full contraction), the same size as Arnold's arms. Those are not big legs, but they were plenty to move my 160 lbs. up hill quite fast, even better now that I'm down to 145 lbs., same leg size. However they are much bigger than my hands.

chelvel

Huh. Thanks for the info. My legs are much smaller BTW (yes much smaller) and I'm on a fence: start them grow or not. I think it's possible.

My question was about HR and leg muscle mass. If that muscle mass will grow what will be with the heart rate for the same work? I do not see why it will go down unless the heart will grow too.