Someoneo `' wrote:
Washedup neverwas wrote:
Speaking as someone who has been both a competitive cyclist as well as a competitive runner (and comp Nordic skier), I can say that cycling can get you plenty fit. Running can get you plenty fit, too. Running will get you more "fit" for running, and cycling more "fit" for cycling. Interesting to note that cyclists and nordic skiers are rather prevalent at the top end of vo2 max records, for example. Just sayin.
Running is a natural full body exercise using all the muscles of the body, and cycling is not, as it uses primarily the quadriceps and very little movement elsewhere.
Vo2 max is a measure of inefficiency, and besides results having a high range, is not a measure of overall body fitness. Having the groups run a 12 kilometer cross country race would be a much better indication.
VO2 max is not a measurement of inefficiency.
It's a measure of your bodies ability to transport and utilize oxygen. This is a significant part, though not all, of what it means to be aerobically fit. If you can deliver, and use, more oxygen you are by definition a fitter individual. Two identical people, one with the ability to use 50 ml/kg/min of oxygen and the other 40 ml/kg/min of oxygen, the one with a measurement of 50 is going to be the faster runner because they have more oxygen and thus ability to produce ATP/generate contraction/go faster.
So VO2 is a big component of aerobic fitness. It is, to a degree, your current upper limit. The other big definer of aerobic fitness though is fractional utilization, i.e. at what percent of your VO2 max can you hold at a steady state without fatiguing (aka FTP/Threshold), i.e. the maximum speed/power you can maintain without needing to call upon stored anaerobic reserves.
Take two individuals with a VO2 of 70 ml/kg/min, and they could have vastly different half marathon times. One might run 1:02, and the other 1:20. Why? Fractional utilization. Athlete A might be able to hold 88% of VO2 aerobically, whereas athlete B might only be able to hold 70%. It can be even lower in those that are untrained.
Then of course the final piece comes down to efficiency. Most guys with high VO2 tend to be the least efficient and guys with lower VO2 tend to be the most efficient. Between this and fractional utilization it's easy to understand why one athlete might have a VO2 of 90 but run a 5k in 15:30, while another athlete with a VO2 of 65 runs a marathon in 2:10.
Bottom line is that VO2 isn't a measure of "total body fitness". It IS a measure of general cardio-respiratory fitness, specifically the ability of the body to deliver and consume oxygen at maximal intensity. A 12km cross country race is NOT a good way to determine who has the best aerobic system. It is a good way to determine who is the fastest runner.