The readers of this blog always manage to get to the heart of the issue. I received this question by email a few days ago. It’s a good one which many aging athletes ponder, I'm sure.
Not a question that would affect training, and obviously the answer would vary by individual -- but, how much does one begin to lose after 30?
I had the chance to use an SRM in '97, and saw 350w for an hour, at 73kg.and 30 years old. I was doing 340w at 74kg in 2010, and then 330w this year after an eight-month layoff from a posterior tibial tendon injury in 2011.
I'm certainly training better and more consistently now than I was in the 90s -- I may have been able to get more than that 350 if I'd had more of a focus on intensity then, but that's just speculation, obviously.
My curiosity now is how much does one expect to lose in one's 40s and 50s?
Yes, that's the ultimate question for the aging athlete. The research using "normal" subjects (mostly sedentary, mostly overweight, mostly poor nutrition, mostly low motivation) says to expect a 1% decline per year in aerobic capacity (VO2max) after age 35. (Lactate threshold and economy have not been well researched in regards to age so we’re stuck with only one performance measure to consider.) There is very little research on older, athletic, fit, etc subjects. The little that exists suggests the decline for this group is more on the order of 0.5% per year after 35—about half of the “normal” decline. I suspect it's less than that if the athlete has maintained his/her training at a high level, which includes continuing high intensity interval-type workouts. Unfortunately, most don't as they get older and so the research is skewed a bit. As the baby boomers age there will be more research done on truly older populations who are more performance-focused. Then I believe we will find the decline to be considerably less than 0.5%.