This was a good conversation. When both Rob and Trevor said time above 90% VO2Max, I was left wondering if it meant power or HR? I know if I change the rest interval on hard intervals, average HR for the work intervals will decrease even if power increases. And the more rest I put in, the more time I’ll have near VO2max workload, whether HR or power. For this reason, I agree with Trevor that just measuring time above a specifed power level or HR probably doesn’t guarantee that a particular interval protocol produces better adaptations.
Another point Rob and Trevor both got to is when to do the intervals and how fast the adaptations are. I am particularly interested because I read about a coach who was recommending that older athletes do high intensity year round (but modify volume) because the adaptations may be slower and rebuilding capacity may take longer. The argument was that one didn’t want VO2 max to drop too much. I’m interested in the VO2Max interval recommendations for athletes over 50. I’m 59 and do a VO2 max session almost every week (30on, 15offx12x 3-4) based on this advice, except for transition periods. I’m presuming I get some neuromuscular work on the accelerations and the intensity work is kept at a baseline. However, I am wondering if I should stop this for extended periods to work on lactate threshold, or increase significantly for peaking.