Q: My track coach is also the cross-country coach and he wants us to run cross-country in the fall. I am a top-level sprinter that competes in the 60m (indoor), 100m, 200m and occasionally the 400m dashes. Doesn’t running 3 to 5 miles a day make me slower?
A: While most times coaches have the best interest of their athletes in mind, it sounds like you may need to approach him on this issue. The old saying, “Train fast, get fast. Train slow, get slow” applies directly to this case.
In your training regimen for track, specifically the races at shorter distances, I’m sure your coach uses a good blend of short to medium distance sprints followed by a set rest period that you may repeat several times. With the distances that you told me you race at, you should be spending at least 90% of your training running no further than 400m. While the intensity and frequency may change based on big meets and events, the distances should remain similar across all seasons.
The problem with running 3 to 5 miles is that when you train for a duration of greater than 2 minutes (equal to a decent 800m time), you will start to shift from anaerobic respiration to aerobic respiration. Furthermore, not only will you be utilizing a different energy system, you will be training a different set of muscle fibers based on the new demands of oxygen in your body. Your body will start to adapt by changing from “type II b” to “type II a” muscle fibers. While both are considered fast-twitch, the “type II a” fibers have a higher oxidative capacity and are so relatively resistant to fatigue. These fibers are used more readily in aerobic exercise whereas “type II b” fibers are used in anaerobic exercise. When your muscle fiber composition starts to change, your ability to buffer lactic acid will decrease, your short distance times will increase, and you will become more susceptible to injury once you go back to running the shorter distances because of the increased load on the decreased number of “type II b” muscle fibers. This is something your coach should take seriously if he wants you to be at peak performance in the spring.
Fortunately, regardless of running cross-country or not, most gifted sprinters are blessed with good genetics and can recover quickly from poor training practices and still perform at a high level in meets. But, if your goal is to achieve at your maximal capacity come winter and spring and try and remain injury free, a proper training program in the fall is necessary.