I'm trying to understand something about my personal physiology and how to become a faster triathlete. This week I did two VO2 Max workouts, one running one cycling. Comparing the running vs cycling: the workouts were "hard" in very different ways, and I'm trying to understand why.
Running -- I ran 8 x 1K repeats on the track on 3 min jogging recoveries, each 1K a few seconds faster than the last. The first couple at 6:00/mile pace were fairly easy/sustainable, but the last couple (5:40/mile) were decently challenging. By the last 200m of each 1K, I was breathing quite hard, almost feeling short of air. But there wasn't really any muscle fatigue to speak of.
Cycling -- I did 5 x 5K repeats on an outdoor cycling track on 3 min recoveries, all 5 were within a few seconds and watts of each other (~8 min and a mere 230 watts which is ~105% of my FTP), all by perceived exertion. My legs burned, more and more each 5K. I felt deep muscle fatigue and power dropped slightly through each interval (vs my running where pace was rock steady). My breathing was never hard, barely above my ventilatory threshold really. My heart and lungs never felt like I was working.
It feels to me a bit like my "muscles" are my performance limiter on the bike, and my VO2 max intervals don't take me anywhere near by VO2 max in terms of cardio-pulmonary stress. Put another way, if you did two VO2 max tests on me, one on a treadmill and another on a bike, I suspect you'd get wildly different values. Right?
I'd much appreciate help better understanding what's going on here from a physiological perspective, as well as an pointers on how to remedy (notably, become a stronger cyclist which is my triathlon Achilles heel).
Running -- I ran 8 x 1K repeats on the track on 3 min jogging recoveries, each 1K a few seconds faster than the last. The first couple at 6:00/mile pace were fairly easy/sustainable, but the last couple (5:40/mile) were decently challenging. By the last 200m of each 1K, I was breathing quite hard, almost feeling short of air. But there wasn't really any muscle fatigue to speak of.
Cycling -- I did 5 x 5K repeats on an outdoor cycling track on 3 min recoveries, all 5 were within a few seconds and watts of each other (~8 min and a mere 230 watts which is ~105% of my FTP), all by perceived exertion. My legs burned, more and more each 5K. I felt deep muscle fatigue and power dropped slightly through each interval (vs my running where pace was rock steady). My breathing was never hard, barely above my ventilatory threshold really. My heart and lungs never felt like I was working.
It feels to me a bit like my "muscles" are my performance limiter on the bike, and my VO2 max intervals don't take me anywhere near by VO2 max in terms of cardio-pulmonary stress. Put another way, if you did two VO2 max tests on me, one on a treadmill and another on a bike, I suspect you'd get wildly different values. Right?
I'd much appreciate help better understanding what's going on here from a physiological perspective, as well as an pointers on how to remedy (notably, become a stronger cyclist which is my triathlon Achilles heel).
Last edited by:
wintershade: May 3, 19 14:13