At lower levels of exertion our bodies can easily keep up with the
oxygen demands of our muscles over long periods of time. Such a
condition is called aerobic (in the presence of oxygen) and that is the
range were we do most all of our training. As intensity increases
we finally reach the anaerobic level were lactate acid builds in our
muscles rapidly and we can hold that pace for only a short period of
time. Anyone knows as they sprint, they can only last maybe 90
seconds.
The level of exertion where we make the transition from
aerobic to anaerobic is referred to as the Anaerobic Threshold (AT) or
more often as the Lactate Threshold (LT). This is not a sharp
point but a transition range. Conditioned athletes can hold just
below the LT for up to an hour. When we are unfit out LT is 65-70
percent of MHR, or lowered. Conditioned athletes can move have a
LT as high as 90 percent of MHR.
We can get a good idea of our LT by doing a 1 hour time trial.
Another method is to gradually increase your pace over a 10 minute
period until you reach the point where you legs feel like rubber and
your rate of breathing suddenly increases (caused by the extra acid in
your blood). Chris Carmichael's rule of thumb, "You are usually at your lactate threshold heart rate when you're breathing hard and it's difficult to carry on a conversation with your riding partner. Before long, your leg muscles will start telling you, too."
If you want to improve your average speed and power, you will want to work at increasing your LT. You do this by riding once a week at an intensity often described by riders as "pushing too hard". It may not be the enjoyable part of cycling but could be the most productive. It increases how much you can do before into the anaerobic zone with lactate accumulation in your muscles. To work on increasing your LT, see the section on Speed Workouts and Zone Training.
Once you know both your MHR and your LT, you are ready to design a
training program. Go to the next section on Zone Training. |