Wednesday, March 21, 2007

Heart Rate Training Cavets from an Expert

There are some good discussions on the racewalking forums in Yahoogroups. Recently there was a conversation about heart rate training. I made a mistake on last Sunday's 5K race by putting too much emphasis on the heart rate monitor--here's what racewalking legend Curt Clausen has to say about it. By the way, AT is aerobic threshold which is somewhat different from aerobic threshold, AeT.

Here's is how AT is defined by Wikipedia:

The anaerobic threshold (AT) is the exercise intensity at which lactate starts to accumulate in the blood stream. This happens when it is produced faster than it can be removed (metabolized). This point is sometimes referred to as the lactate threshold, or the onset of blood lactate accumulation (OBLA). When exercising below the AT intensity any lactate produced by the muscles is removed by the body without it building up.

And here is Curt's advice: 

I've used heartrate for years in training and racing. The major caveat to
using it in a long distance race (or workout) is that heartrate rises
substantially with dehydration, yet AT pace remains about the same. We've
tested this with blood draws over 4x8k & 4x5k race pace sessions. The
heart-rate can increase dramatically by the last stages in a longer effort
while holding a pace that is under AT. So the correlation between HR and AT
breaks down a bit especially in hot weather. If you don't account for this
in racing you will ultimately be using the HR monitor as an unnecessary
break and not race to your fullest potential. In my better 50k's I raced
with beginning HR at/under 150 and last 10k heartrate high 160's.

Curt Clausen