Without question, all young people who compete in fall sports should perform appropriate exercise programs to enhance their physical fitness. Of course, some of the training procedures will vary based on the demands of the activity. For example, football players should emphasize power exercises such as sprinting, cross-country runners should focus on endurance exercises such as three to five mile runs, and soccer players should include both sprinting and sustained running such as 100 yard dashes and half-mile repeats.

But when it comes to muscle conditioning, I propose that a similar strength training program may be successfully applied to all of the athletes. Oh, there are some differences, such as the number of repetitions completed. Generally speaking, power athletes respond best to lower (4 to 8) repetitions with relatively heavy weightloads, endurance athletes respond best to higher (12 to 16) repetitions with relatively light weightloads, and combination athletes respond best to moderate (8 to 12) repetitions with moderate weightloads.

However, when it comes to the exercise selection all of these athletes should be strong in all of their major muscle groups. Regardless of your sport, there is no advantage in having a weak upper body or a poorly conditioned midsection. Going a step further, training some muscle groups more than others can be a serious disadvantage.

Years ago when I was a university track coach, I determined that sprinters should have powerful quadriceps muscles to explode out of the blocks, and flexible hamstring muscles to prevent hamstring pulls. All winter we strengthened their quadriceps and stretched their hamstrings, and I couldn't wait to see the results of my specialized conditioning program. As it turned out every single sprinter pulled a hamstring muscle and I was dumbfounded. What had I done wrong?

Simple. I unintentionally promoted a serious imbalance between the sprinters' opposing muscle groups. You see, a powerfully accelerating quadriceps group must be properly decelerated by a relatively strong hamstrings group. If the hamstrings muscles are significantly weaker they will be overwhelmed by the stronger quadriceps muscles, and injury is inevitable in spite of their flexibility.

So what should I have done to better condition and safeguard my sprinters? Clearly, I should have strengthened all of their major muscle groups, especially their hamstrings and quadriceps. Years later, working with the Notre Dame High School track and cross-country teams, I discovered how well the comprehensive conditioning approach really works. All of the athletes trained all of their major muscle groups, and the result was one injured runner in four years, and four consecutive Massachusetts and New England championship teams.

But why would football players train with the same exercises as cross-country runners or field hockey players? Because they all have the same major muscle groups. Let's take a look at the major muscles of the body, and the basic free-weight and machine exercises that strengthen these muscle groups.

Many people mistakenly believe that strength training inevitably results in larger muscles and more bodyweight. This is not necessarily true. Strength training produces stronger muscles in all cases, but gains in muscle size and bodyweight are very dependent upon personal genetic factors. For example, most football players have mesomorphic physiques that respond to strength exercise with relatively large changes in muscle size and body weight. On the other hand, most cross-country runners have ectomorphic physiques that respond to strength exercise with relatively small changes in muscle size and body weight. Furthermore, the heavy weightload - low repetition training followed by football players maximizes muscle strength and size, whereas the lower weightload - higher repetition training performed by cross-country runners emphasizes muscle endurance without additional bodyweight.

The main point is that all fall sports participants can benefit from a standard program of strength exercise, and that the results will be specific to each type of athlete. A stronger athlete in any sport is a better athlete, and more importantly, a more injury-resistant athlete. If your fall athletes are not presently performing basic strength exercises, like those presented in the table, you can greatly enhance their sport safety and success by starting a sensible strength training program. Thirty minutes a day, twice a week, is all the time and energy requirements necessary for some significant physical benefits.

Wayne L. Westcott, Ph.D., is fitness research director at the South Shore YMCA in Quincy, MA., and author of several fitness books including the new releases, Building Strength and Stamina and Strength Training Past 50.