Legs burn out before cardio does

warriorcliff77

Greetings from sudbury ontario canada all!

Just getting back into cycling after 20 years

My question is:
I have been cycling 20km/12.5miles 3-5 times a week for the past 2 months.
I'm finding that my legs burn out before my cardio does. Is it a set up issue, or do i just keep on cycling in hopes that the muscles will catch up?

daveryanwyoming

Hard to say what you mean by that, but everyone's legs burn out before their cardio does if you're actually talking about heart function in terms of cardio. Same answer if you're talking about lung function vs. legs.

But cardiovascular fitness isn't just the heart or just the lungs, it includes the way the muscle fibers in your legs have adapted in terms of increased mitochondrial density, increased capillary density, recruitment and conversion of muscle fibers to the types that support aerobic fitness, etc. The point is cardiovascular fitness or cardio isn't just in the upper part of your body and it includes adaptations to your leg muscles as well as changes to the heart like increased stroke volume. So you might be feeling it in the legs(most of us do) but it's still "cardio" or better yet aerobic fitness that you need to improve with sensible training.

From that standpoint focus on longer steady efforts that get you working fairly hard but not suffering or gasping. Short hard, make ya puke intervals won't do a thing for aerobic fitness(they can help anaerobic fitness but that should come much later and only if you're training for certain competitive events) but steady longer efforts of 10 to 30 minutes will help a lot. The key is to do these hard enough that you're breathing deeply and need to focus but not so hard that you feel like you're gonna die. That will build the kind of overall aerobic fitness in both your heart(increased stroke volume) and in your legs(all that other stuff I mentioned). That's really what cardio is about and it doesn't just happen in one place.
I can't speak for your setup, but a good fit does go a long way to keeping you efficient and comfortable on the bike as well as helping you avoid overuse injuries. It doesn't cost much to get a good bike fit from your local shop and if you have any doubts it's well worth the price.

And yes, we all have to just keep cycling to allow our muscles and the rest of our systems to continue developing. I'd make sure you're not just going out and hammering big gears until your muscles sieze up, that's not the way to get fit on a bike. But you do need time and effort on the bike combined with good solid rest between workouts for your fitness to improve. And it's a continual process for folks that want to be competitive or to ride longer harder rides. As Greg Lemond said, It doesn't get any easier, you just go faster.......

Good luck,
Dave

Azza_B

Everything the guy posted above is right however my bet is your reaching peripheral fatigue way before central fatige becasue a) fibre type adaptation needs to occur or more likely b) your cadence is too low therefore your limiting factor will be your legs 90% of the time if untrained.

Hope any of that helps and it awsome your getting back on the saddle.

Az