For most people, a single set of 12 to 15 repetitions with the proper weight can build strength and improve fitness as effectively as can multiple sets of the same exercise. The important point is to exercise your muscles to fatigue — meaning that you can't lift any more with that muscle group. When you do this, you stimulate factors in the muscle that contribute to improved muscle strength and growth. And one set performed to muscle fatigue provides you with almost all the same benefits as a multiset program.

The one-set approach also has the advantage of saving time, which makes it easier to fit into an exercise routine. The Department of Health and Human Services recommends including strength training exercises for all the major muscle groups into a fitness routine at least two times a week.

During strength training, simply choose a weight or resistance heavy enough to tire your muscles after about 12 to 15 repetitions. As this becomes easier, gradually increase the amount of weight to keep doing 12 to 15 repetitions at a weight that tires your muscles.

It's important to use proper technique to avoid injury. Also, take time to rest between each exercise to give your muscles time to recover.

Although a single set of strength training exercises can improve muscle strength and fitness, the number of sets that you perform may differ depending on your fitness goals. For example, if you're a bodybuilder or an elite athlete with specific performance enhancement goals, then additional strength training sets may be appropriate.