It is hard to resist the temptation to spend the most time on your best sport. Photo: John Segesta
It is hard to resist the temptation to spend the most time on your best sport. Photo: John Segesta

Tim Mickleborough addresses the dilemma many athletes face when it comes to balancing all three sports: How much time should be devoted to the sport that needs the most work?

Written by: Tim Mickleborough, PhD

Dear Speed Lab,

I compete mostly in Olympic-distance triathlons. My athletic background is in swimming and biking. I am finding that my run is a problem; in training and actual races my run is sub-par. I am wondering if I am spending too much time training in my stronger sports and not devoting enough time to running. I would say I average about 12 to 15 miles of running per week. The athletes I train with think that my run mileage is way too low. What do you think?

Robert Galway
Santa Rosa, Calif.

Dear Robert,

It is important to remember that the purpose of training is to stress the body so that when you rest it, it will grow stronger and more tolerant of the demands of triathlon. Unfortunately, endurance athletes often forget that you can train too hard or allow too little rest, which over-stresses the body and allows no opportunity for growth.

Some years ago, David Costill at Ball State University studied two marathon runners following a six-month break from running when they were at different stages in their reconditioning. As they gradually increased their weekly mileage, they underwent muscle biopsies and VO2max tests. As would be expected, the tests showed dramatic improvements in aerobic capacity after running only 25 miles per week. The runners eventually increased their weekly mileage to 50 and then to 75 miles per week. Beyond that level of training, the laboratory tests showed no additional gains in endurance. Indeed, during a one-month period, they even ran 225 miles per week with no improvement in endurance.
The take-home message is that there is a point of optimal distance that will cause the body to adapt to its full aerobic capacity. However, there is also a point of diminishing return, a point at which you can increase weekly mileage but see little or no improvement in performance.

Your current run mileage is rather low, so there are physiological advantages to be gained from additional mileage, but you need to be careful to not increase your mileage too quickly. The body is capable of tolerating slightly greater amounts of stress, but taking on too much too fast can lead to breakdown. You should increase your weekly mileage by 5 percent to 10 percent per week to avoid becoming chronically fatigued.

Your training program should allow for adequate recovery. Most athletes attempt to train hard every day, with the idea that the more they do, the better they will be. Running at the same pace each day does not allow you to inject any quality or speed into your running program. It is important to note that the rate at which the body adapts to a training stimulus is relatively slow. You may not see the benefits gained from a given workout for several weeks. The training regimen should be planned over a three- to four-week period, rather than day by day or week by week.