One of the most interesting, hard, and useful activities at camp happened Sunday morning. John first discussed training intensity zones, then had us run a max heart rate interval session. The results are fascinating.

Training Zones

John's talk on training zones went on for almost two hours. What follows is a very short summary of some of the high points. The talk was much more detailed and evoked quite a bit of discussion. This write-up is very simplistic by comparison.

Training Levels as discussed in this camp are estimated as follows and averaged to the nearest 5 beats for ease in remembering (hey, it's not an exact science) - you'll see some real estimated from the camp later in the article.

These zones are starting points and can be adjusted by feel, lactic testing, average race heart rate, aerobic capacity, etc. to fit the individual racer. (Digression: There are also many different ideas about where these starting points should be. See Different Ways to Determine Training Zones for a discussion).

At 60% of max heart rate, the heart fills up with blood during each stroke. The training effect begins here. At low intensity training (60-70% or max heart rate), the body builds capillaries which help supply blood to the muscles. At higher intensities, you work the heart muscle more.

One of the ancient rules of thumb is that you want to do quality training (intervals, pace sessions) around your Anaerobic Threshold (AT), and your AT is roughly your average race heart rate. But your average race heart rates depends on the length of your race: You can race much harder (i.e. at at higher average heart rate) during a short sprint than during a 50 km marathon. If you only do 50km marathons, there's not that much benefit of doing Level 5 training - you generally race at a lower heart rate. If you only do sprint races, more training needs to be done in Level 5 because much of the race may be a Level 5. For those of us who race a variety of races, we need to train at each level..

According to John, the typical AT for someone doing a 15 to 20 km race is in low to middle range of intensity 4. The longer the race, the lower the average heart race - maybe into Level 3. The shorter the race, the higher the average - maybe into Level 5.

What's My Zones?

If you want to train in the different zones, you need to know what they are. To determine your zones, you need to know your max heart rate. The old "Subtract your age from 220" maybe gives you a ballpark figure, doing a ski walking session on a treadmill gives you a much better estimate (if you have the time, money, and one is available), but the most practical way is to run a max heart rate test.

This works easiest if you have a heart rate monitor, although some people did do it without one. I think they tended to go too fast during the initial intervals. To run this, you need to have an estimate of your max heart rate. Use the  "Subtract your age from 220" if necessary - the end result of this test is to figure out your real max heart rate.

You'll also want a sheet of paper and a pencil, unless your heart monitor stores interval-level information in memory that you can retrieve later.

We all warmed up by running a relatively flat loop with a couple gentle rises, ending on an uphill. At an easy pace, the loop took about 5 minutes. Nothing fancy about this loop - we created it during our warm-up run. We ran the loop a couple of times, did some stretching, did a couple 10 second sprints, caught our breath. Then the intervals started:

• Interval 1: Over the first minute, speed up to your max HR minus 30 beats. If your max heart rate is 180, this interval should be run at 150 beats per minute. Slow down on the uphills to maintain the target heart rate. Check your heart rate monitor frequently! At the end of the interval, write down you time and what you think your average HR was during the interval.
• Interval 2: Do interval one over again, except at max HR - 25 beats.
• Interval 3: Run at max HR - 20 beats.
• Interval 4: Run at max HR - 15 beats.
• Interval 5: Run at max HR - 10 beats or harder. In the last minute speed up. In the last 30 seconds, max out! It should hurt! Check your heart rate monitor as soon as you stop to see heart rate - it should be your max or close to it. You also want your average heart rate for the distance.

There was full recover between intervals - rests were roughly equal to the length of the previous interval.

Test Results

Of the 14 racers who ran the interval session, half had to reset their max heart rate either up or down (mostly up). One racer found out his max heart rate was actually 10 beats higher than he'd ever observed in a race. Here's the results of seven racers (I took a subset for space reasons). The "Interval 5" heart rates are averages for the interval, not max:

It appears several racers took off at too high a rate in the early intervals - they must have suffered on that last interval!

Because everyone has a different max heart rate, it becomes pretty irrelevant to compare heart rates with your buddy during a training session. Better to compare your percentage from max to see if your efforts are about the same.

These estimates of the training zones are just that - estimates. They may need to be adjusted based on how fit you are. For example, the fitter you are, the higher your AT zones will probably be. In sports you don't do very often, the heart rates for each zone may be lower because your not as efficient. They might be different for doublepoling (where you use only your upper body) compared to techniques that stress the whole body. Use perceived effort or other indicators to adjust the zones as necessary.

This is a great interval session for use the rest of the year because it stresses your heart at each of the different zones you may use in different length races. Remember that you don't need to instantly accelerate to the target zone, and you don't need to try to reach your max on the last interval.