You can expect to slow down as you get older but perhaps at a faster rate if you only train long and slow. That’s the bottom line from Part 3 of this series on aging and performance. If you never fully challenge your aerobic capacity it will decline. Use it or lose it. The way to challenge aerobic capacity is with high intensity – very high.
Now, bear in mind that if you are an older athlete (let’s say that means older than 50 for the sake of this discussion) and have never done any above-lactate/anaerobic threshold intervals in training then now is not the time to start. If this describes your situation I’d suspect that you have never come close to achieving your aerobic capacity potential. And since aerobic capacity is one of the three determiners of overall fitness, your race performances might be less than stellar. Keep in mind, however, that the longer your race distance is the less important aerobic capacity is to performance (3). Trying to take your aerobic capacity up a few notches by suddenly doing VO2 max intervals (more on those in a bit) is likely to result in injury, especially if you are a runner. So what should you do in this case?
I’d recommend doing intervals at or slightly below lactate/anaerobic threshold once a week for about 8 to 12 weeks to get your body ready for the greater stresses of aerobic capacity training. Some athletes will have no problems while doing these LT/AT workouts twice a week so long as there is adequate recovery between the workouts. That generally means at least 48 hours of only easy (low-intensity) training. In my Training Bible books I call these workouts “cruise intervals.” They are relatively long work intervals with relatively short recovery intervals. The work intervals are typically in the range of 6 to 12 minutes with recoveries that are a third to a fourth as long as the work interval. So, for example, the workout could be 3 x 6 minutes at heart rate, power or pace zone 4 with 90-second to 2-minute recoveries (my HR and pace zones, Coggan’s power zones). Start with about 12 to 20 minutes of total zone-4 time in a single workout (shorter for running than cycling or swimming). Gradually increase the work-interval volume in each session. The upper end is typically in the range of 20 to 40 minutes of total zone-4 time (again, shorter for runners). These workouts are better done with a power meter (bike) or speed-distance device (running) than with a heart rate monitor. Heart rate isn’t sensitive enough for intervals done at or above LT/AT.
If you follow the cruise interval route, after a few weeks you’ll be ready for VO2 max intervals. If you’ve been doing LT/AT training already then you should be ready to jump into the higher-intensity, VO2 max sessions right away.
Here’s how to do these VO2 max sessions. Once a week do work intervals of 2 to 4 minutes duration at zone 5 power (Coggan) or zone 5b pace (mine). Again, heart rate is of little value here due to the time it takes for it to “catch-up” with the intensity of each interval. Recover for about the same amount of time as the preceding interval. Get in 12 to 15 minutes of zone 5b pace or zone 5 power in a session. So the workout would be something like this…
1. Warm-up
2. 5 x 3 minutes at zone 5/5b (3-minute recoveries)
3. Cool down (or work on another ability such as muscular or aerobic endurance)
The biggest mistake made when doing this workout is to start each work interval at too high of an intensity and get slower as it progresses. This then leads too much fatigue early in the session so that the athlete is unable to finish the workout or slows so much in the latter intervals that they are of little value. I insist that the athletes I coach make the first interval the slowest (yet still in zone 5/5b) with the interval’s intensity rising slightly from start to finish. The second interval is only slightly harder with this gradual increase continuing on each subsequent interval. Within each interval the intensity also gradually increases.
There is some research showing that even shorter intervals are affective for building aerobic capacity (1). Thirty-second intervals with 30-second recoveries seem to be just as good. Similar results have even been found with alternating 10 seconds on with 10 seconds off. While shorter work bouts may work just as well, longer intervals are less likely to be as beneficial. The problem is that you can only maintain VO2 max pace or power for about 5 to 6 minutes. And that is excruciatingly difficult. So 1 or 2 intervals of this length is perhaps all you could manage in a single session due to fatigue. Whereas with intervals of about 3-minutes duration you should be able to complete 4 or 5 getting in more total time at aerobic capacity in a single session.
The great thing about doing VO2 max intervals is that they not only improve aerobic capacity but such training has also been shown to improve lactate/anaerobic threshold and economy (2). And if you recall from my previous posts on these topics (see links here and here), these three are what training for endurance sport are all about. So even if I’m wrong about aerobic capacity being the most important of these for the aging athlete, doing VO2 max intervals will also positively impact the others still improving your performance. That’s why I have serious athletes of all ages do these at some times in their seasons. When to do them varies based on the event one is training for, however. And that is the topic of Part 5. (Sorry to drag this out, but it’s turning into a bigger project than I anticipated.)
References
1. Bangsbo, J., T.P. Gunnarsson, J. Wendell, L. Nybo and M. Thomassen. 2009. Reduced volume and increased training intensity elevate muscle Na+/K+ pump {alpha}2-subunit expression as well as short- and long-term work capacity in humans. J Appl Physiol 107(6): 1771-80.
2. Billat, L.V., B. Flechet, B. Petit, G. Muriaux and J.P. Koralsztein. 1999. Interval training at VO2 max: Effects on aerobic performance and overtraining markers. Med Sci Sports Exerc 31(1): 156-163.
3. O’Toole, M.L. and P.S. Douglas. 1995. Applied physiology of triathlon. Sports Med 19(4): 251-67.
