With all the benefits that strength exercise can offer, why do so few distance runners include this activity in their conditioning program? Primarily because the typical strength training workout is just as aversive to distance runners as the typical distance running workout is to weight lifters. Distance runners do not need a two-hour strength workout to improve their muscular fitness anymore than bodybuilders need a two-hour run to improve their cardiovascular fitness. However, in our experience, competitive distance runners and triathletes obtain excellent results from relatively brief strength training sessions.

Referring once again to the physiological and morphological changes during pregnancy, there are reasons that limit the ability as well as the desire to exercise at an intense level during pregnancy. Non-weight-bearing activities have proven to be successful alternatives for maintaining a high - intensity , moderate - duration regimen of exercise training throughout the third trimester ⁵. However, pregnancy itself is a weight-bearing activity that increases in intensity for 9 months.

Recommended Strength Training Program
First, our research with over 1100 adults shows that two strength training sessions per week is about 85 percent as productive as three strength training sessions per week ². I therefore suggest that you begin with just two strength workouts per week, on days when you do easy to moderate effort training runs.

Second, since single set strength training seems to be as effective as multiple set workouts, I recommend just one good set of each exercise³. This greatly reduces the exercise time as well as the risk of overtraining problems.

Third, because successful distance runners typically have higher muscle endurance (due to a greater percentage of slow-twitch muscle fibers), they generally attain better results by strength training in higher repetition ranges. Whereas power athletes thrive on four to eight repetitions per set, endurance athletes are better served with 12 to 16 repetitions per set ⁴. In my opinion, using the proper repetition range may be the single most important training factor for successful strength exercise experiences.

My fourth recommendation for distance runners is movement control, which is best exemplified by moderate to slow speed repetitions. Fast weight training movements involve momentum which reduces strength development and increases injury potential. A safe, effective, and time-tested training speed is six seconds for each repetition, or about one minute for a set of 10 repetitions ⁵. Each lifting movement should be performed in about two seconds, and each lowering movement should be performed in about four seconds. By slowing down the otherwise easier lowering movement, both phases of each repetition become productive for building strength. Keep in mind that one set of exercise performed at six-seconds per repetition requires as much muscle tension as three sets of exercise performed at a more typical two seconds per repetition.

Finally, the key to building musculoskeletal strength is progressively increasing the training resistance. This is what makes free weights and machines superior to bodyweight exercises. Whenever you can complete 16 properly performed repetitions of an exercise, increase the resistance by about five percent for continued progress.