People often times get confused about what muscle endurance is and how to train to improve it. This is especially important in training women since many are afraid of “bulking up”.

First of all, muscle endurance is the ability of a muscle or muscle group to repeatedly contract without fatiguing. If you were riding a bicycle for a 40 miles, the thigh and leg muscles would be demonstrating their muscular endurance as they would be contracting with each pedal stroke for this distance.

Muscle endurance is not the same as cardiovascular or aerobic endurance which illustrates the ability of your body to deliver oxygen to the body tissues. One would have a different workout emphasis to improve the heart and lungs and blood delivery of oxygen to the tissues than for muscular endurance as the emphasis. At the same time, training for one dimension of health like muscle endurance in the bicycling example, doesn’t preclude you from improving cardiovascular endurance. Chances are you would improve both even if that is not your goal.

Secondly, I am writing about muscle endurance because, as a female, I often hear women say they want to participate in a weight training program but not if they are going to “bulk” up. Commonly the trainer leading them in such a routine will suggest the use of lighter weights with many repetitions so they can improve muscular endurance in lieu of getting bigger muscles.

As a certified personal trainer, a university professor, and a woman with many years of experience in health and fitness from a variety of perspectives, this desire to “tone up” rather than “bulk up” always serves as a source of discussion for me.

First of all, women don’t have the testosterone levels to significantly increase the size of their muscles. Pick up an exercise physiology text and you can read the research that documents such. Secondly, women, especially pre- and post-menopausal women, need to lift a decent amount of weight to stimulate bone health which is decreasing as we age. Bone loss is especially substantial in the years following menopause. Another reason to engage in a weight routine with some “healthy” amount of weight, is to prevent sarcopenia, a loss of muscle mass which is usual with the aging process.

Bone loss or poor density can translate into fractures. Loss of muscle mass demonstrates a loss in strength. Both indicate a decreased ability to accomplish daily life tasks and ultimately, independent living can be the cost.

What would I suggest as an appropriate program for muscle endurance? Choose a weight for each exercise that is about 65% of the maximum weight you can lift in that exercise. For instance, if you can leg press 100 pounds, then you should have about a 65 pound load to train for muscle endurance. Press this 65 pound load for more than 12 times or repetitions. Rest 30 seconds, Repeat. Perform 2 or 3 sets of this exercise. Advance to the next muscle or muscle group and use the same “routine”.

Too many times, people are not engaging the principles that allow them to build muscle endurance. Too frequently, one set is performed and then a person “chats” with someone nearby and 5 minutes has passed before attempting the second set. For endurance, the rest periods must be short. Also, in many cases, the weight is too light for the benefits of helping the muscle “endure”.

If your goal is to build the endurance of a muscle, then you must lift the appropriate weight (about 65% of max for that exercise) and have short rest periods (less than 30 seconds). With such a program, a person will build some level of strength because you can’t improve endurance without some improvement in strength. But, the overriding improvement will be in the endurance of the muscle.

Women won’t likely increase the size of their muscle with this programming but they will achieve greater benefits by a heavier weight and shorter rest periods that are closely monitored and recorded than from previous “random” attempts at lifting without enough weight and rest periods of too great a length.

Finally, what if a woman gains a little muscle mass? If improving bone health and muscle endurance and strength is achieved so that quality of life is improved, isn’t this a small cost?!