Tuesday, September 28, 2010

when an endurance runner tries to bike

Had a fun weekend... I felt I was not going to be in good enough shape to run the VT50K this year so I decided to bike the VT50 instead.  Because in some warped way I thought biking 50 miles was easier than running 31 miles. (plus I had gone on a few mtb rides and felt really good).  Turns out it IS easier... maybe because you don't have to stand the entire time.  Or maybe because you don't have to work as hard on the downhills and flats.  Which leads to my gripe...

Maybe because I'm a runner I bike different...when you run you never get to coast.  If your legs stop moving you stop.  So that is how I bike... almost always pedaling.  Uphills, flats, downhills (except when negotiating single track).   I wasn't sure why I was passing so many people on the downhills and flats (and I'm not talking about single track here... I'm talking about road and double track sections).  Why were they going so slow?  Weren't we racing?  My heart rate/breathing was very comfortable and aerobic yet I was still passing people on the flats and downhills.  I'm not THAT heavy so I know that's not why I was faster downhill.   I can only assume the expert riders don't do this... they must keep up their level of effort on the flats and downhills... but since they started ahead of us, and were obviously faster, I didn't get to see how they ride so I guess I'll just have to wonder.

Still perplexing (but maybe less so than the downhill-coasting conundrum) is that all (ok... that's generalizing, but it seemed like too many) of the bikers attack every hill climb like they are sprinting for the polka dotted jersey and then they get to the top they virtually stop moving, pedaling slow or not at all.  Its amazing how many bikers passed me on the climbs and then within 30 seconds of cresting the hill they were panting for air barely moving and I was long gone, still pedaling away. 

Maybe many novice and sport riders don't spend much time thinking about physics or haven't researched the bodies energy systems and training zones etc.  When I endurance race I think of relatively consistent energy output to avoid excessive anaerobic efforts (obviously there will always be power demand fluctuations but you can control how extreme they are).  To put that in perspective... if you had constant energy output (lets say 100 watts) going 3 mph on a 10% grade hill takes the same power as going 14 mph on a flat.  Or another way of putting it... to maintain your speed of say 10mph going from flat to a 10% hill you would have to increase your power output by a factor of more than 6!  (You can play with the numbers at http://bikecalculator.com/veloUS.html since it obviously varies with rider weight, power output, and more)

So why were so many people coasting on the downhills, probably at low low heart rates and then killing themselves on the hills so they were nearly spitting up a lung?  When they could be flying on the downhills and setting a tolerable pace on the uphills and overall holding about the same total riding time with a lot less fatigue.  I could be wrong, but I think I felt better at the end of the race and had more fun than the hill-sprinting/downhill-coasting riders.

Again I didn't get to see how the experts ride so I can't comment on them... was it just inexperienced endurance racers that stood out in my mind? or is biking totally different than running? or is it a male/female things since the guys tend to have more strength/power and don't need to pace themselves as much?  Any expert riders out there I'd be curious to hear your endurance race approach... maybe your racing is more refined than what I saw in my first endurance mtb race.

Regardless I had fun race and would do it again.  :)  The 50 mile course is a lot more fun than the 50K course.  Much more fun single track.  Trail running is still my favorite... just not for this race.


  1. I love the sciency-spin on your post, Raina. I'm glad you wrote about it because I don't think I really ever thought about maintaining a constant output... this will definitely be a help in future races! And great job doing a 50 miler! You must really love your mtn bike. :)

  2. I LOVE my bike