Intervals and Recovery

Arthur from Berkeley asks

I am a novice at race training, having ridden as a serious tourist for many years. I have signed up for some coaching, which so far has been pretty easy. Lots of endurance riding, plus strength training. Recently we started intensive intervals, and I wonder if these are structured appropriately for masters. I am 48, and my AT (using the Conconi test) is 171, with highest HR observed at 181. Our intense intervals are as follows: warmup for 20--30 minutes at HR under 100, then 3 minutes at 160--180, then recover for 4 minutes at HR under 90, repeat for a total of up to 6 times, or until we can't get our HR that high, and then cool down at 100 for 15 minutes.

My problem is that my HR won't go down to 90 unless I get off the bike. If I ride on rollers at 6.5 mph, it takes about 6 minutes to go down to 120 or so. I then rest for 4 minutes at this rate, for a total of about 10 minutes rest. I have found that it's not problem to do all six intervals, and in fact my speed when I do the sixth interval at the same HR is down by 2 mph, and the interval feels almost easy. On the other hand, after the whole workout, I was quite tired.

My general question is, how should master's modify their intervals so as to take into account their slower recovery rate?

The Coach responds:

There are various types of intervals that you should do at different stages of your program. In the early stages of your program (first 5 weeks), you should do one interval at E1 (75 per cent of max HR) for the total daily distance less 10 kms to warm-up at RE HR and the same to warm down. In the second macro (a 6 week phase) the intervals change but still emphasise strength and endurance. So you should define your RE as your Individual Aerobic Threshold 1 (IAT 1) which is a scientific measure based on a lactate analysis. The IAT1 is approximately 60 per cent of your max HR.

In the first few weeks of Macro 2 you start doing intervals on steep and long hills pedalling at 60-70 revs per minute whenever you come to a climb. In the third 5 week Macro, a typical effort day (say 100 kms) would look like - 15 kms RE (IAT1), 3 by 15 minute at IAT2 (which is approximately 90 per cent of max HR), with RE (at E1) in between, warming down with 15 minutes at IAT1. By the third week of Macro 3, the IAT2 intervals get longer (20 minutes). In Macro 4, speed intervals start with step-routines (10 pedal strokes as hard as you can pedal saddle, 10 strokes off, 15 on, 15 off, 25 on, 25 off up to 45 on and 45 off - or whatever you can bear), flat road-big gear 200 metre sprints, circuit sprints on a square (350 metres flat out, corner, sprint the next 350 metres, corner, sprint, corner, sprint, corner).

My observations in your case:

You must build up to very intensive intervals over time. Strength and endurance must come first, and takes at least 10-12 weeks to acquire, presuming you start out fairly fit in the first place.

You warm up for 20-30 at HR under 100. Yet your max HR is 181. That is not a good way to warm up. You should warm up over 20 minutes until you are at 75 per cent of the max. That way you are primed to work hard. At a HR below 181 (less than 55 per cent of your max) your cardiovascular and muscular system is not prepared to move up to around max for 3 minutes.

You also are doing intervals for 3 minutes between 160-180. That is a span of effort from around 88 per to within one beat of max. This is far to inexact. How do you decide the effort. In my program, every is worked out with respect to some defined threshold or IAT. I would suggest you do these shorter efforts at IAT2+5 which will give you around 92 per cent effort.

To do these intervals for up to 6 times or until your HR cannot go up to this level begs the question of which level, 160 or 180. If you cannot get up to 180 it means you are exhausted. If you cannot get up to 160 it means you are unfit and not ready to do these intensive efforts and should go back to Macro 1.

The correct measure of recovery is not how quickly your HR falls below some threshold. The better measure is provided by your lactate recovery rate. In my own case, when I am in the early stages of my buildup (Macro 1 or early Macro 2) my HR falls quickly to below 100 after an exhaustion test, but my lactate levels remain high around 6.0 after 5 minutes (RE = 0.8). After 10 weeks or so, my HR stills drops quickly but so does my lactate level, reaching around 0.8 after 5 minutes. I realise that this degree of science is not usually available but it just makes the point that HR recovery is misleading. A proximate indicator of recovery is what happens next morning when you take your resting HR and standing HR upon rising. You should monitor this relationship. Usually it is a steady differential. If you have been overtraining or have not fully recovered then the difference will be larger (how large depends on the person - in my case I am sensitive to one or two beats per minute extra on the difference).