5 Factors Behind Exercise Discomfort
Exercise can be uncomfortable when beginning any new type of training or when getting back in the saddle after a long break.

In last week's column I talked about the discomfort of exercise when starting out and also when competing at the elite level. It's universal; it happens to everyone, and it is not a sign that you are not cut out for exercise. On the contrary, everyone is cut out for exercise. And for the vast expanse of training levels between the two extremes, exercise is a feel-good experience - most of the time.

Even in the middle, however, a little discomfort now and then is not unusual or unexpected. And it's not a sign to quit your fitness program. Instead, I use it as an opportunity to get to know my body better. You can do so as well by breaking down any exercise discomfort you experience into its essential components.

Exercise physiology physician Massimo Testa, M.D., advises athletes to assess exercise discomfort as a combination of five factors:
  • Your level of fitness
  • The intensity of the exercise
  • The degree to which you can tolerate the exercise
  • Your motivation to keep exercising
  • The degree to which you perceive you are suffering
The first factor comes into play when, say, walking three miles feels hard because it's way beyond your fitness level. The other four factors may all be negligible - the pace is not too intense, you can tolerate exercise well and feel motivated, and sunshine mutes any grumbling - but your newness to fitness alone can spike your feeling of discomfort. Once you are walking five miles at a pop regularly, however, walking three miles won't even register on your discomfort radar. The work your body does to walk three miles won't change, but your improved fitness will shrink your discomfort.

Meanwhile, if you exercise at an intensity that is 70 percent to 80 percent of the greatest intensity you could possibly do, you (or anyone) will be uncomfortable starting out. After you're experienced training at that intensity, though, you won't be uncomfortable with pushing yourself that hard. That's essentially the basis of interval training: You train at a higher intensity in short bursts (say, a few minutes) interspersed with rests (blocks of time at low-intensity) and soon higher-intensity exercise doesn't hurt quite so much, because your muscles and lungs are getting in better shape.

Your brain also gets in better shape, creating a greater tolerance for exercise. As it learns to manage greater fatigue, your brain will interpret the same signals from your body differently.

Likewise, the signals to your brain (or your interpretation of them) change with your level of motivation. As you exercise, the level of signals coming from your body has a value - a number from 1 to 10, say - but the message from your cerebral cortex modifies that value, given your motivation. A 7 today can feel like a 10 next week if it's raining and you don't want to be out there. Other days, it can feel like a 3, if you're with friends.

This is where the chatter going on in your cerebral cortex is cardinal to your fitness: It's responsible for telling you how long you want to push yourself, either I can't stand this another second! or I can hold this for another 30 seconds. You can control that chatter - and thus the impact of the motivation variable - very effectively.
