When it comes to strength training, the one-size-fits-all approach doesn’t work. Your level of fitness and muscle-building goals are important facts in determining the best approach for you. Muscle development is split into three categories: increasing muscular strength, improving muscular endurance or enlarging muscle size. While either heavy weights or more repetitions are beneficial to your muscular development, you have to consider your age, experience and form to prevent exercise-related injuries.
Aim Low, Score High
Questions have been raised about the effectiveness of building muscles with light weights due to the myth that light weights will only “tone” your muscles. In a 2010 study published in “PLOS ONE,” Dr. Phillips and a team of researchers set out to determine whether light weights with high reps is more effective than heavier weights with low reps in stimulating muscle growth. The 15 young men participating in the study lifted either heavy weight that was 90 percent of the maximum weight they can possibly lift; or lighter weight that was 30 percent of their maximum. Both groups continued lifting the weights until their muscles were too fatigued to continue. The researchers concluded that lifting lighter weights with more repetitions is more effective than heavy weights with low reps when you exercise to fatigue.
Safer Route Burns More Calories
Dumbbells are free weights, which take more muscle and joint coordination to use than machine equipment. The higher degree of motion with dumbbells also increases the risk of injury -- and even more so with heavy weights. Light weights give you a greater degree of control while lifting, which can help prevent muscle pulls and strains. Dr. Phillips states that working your muscles to fatigue takes longer with lighter weights, which results in a higher rate of calorie expenditure than a heavy weight training session.
Reps to Shoot For
Determining what constitutes as “light weight” is dependent on how many reps it takes you to fatigue. Dr. Phillip tells “The New York Times” that with light weight, 15 to 20 reps should cause muscle fatigue for muscle growth and strength. If you can easily perform 20 repetitions or more, then the dumbbell is too light and if you are unable to perform at least 15 reps, it’s too heavy.
It’s Not Necessary to Lift Heavy
Older adults and beginners benefit the most from using lighter weights to exercise because they are more likely to suffer from muscle-related injuries than well-conditioned weightlifters. However, you should ask yourself whether using heavy weights is necessary at all. In a study published in 2012 in the “Journal of Applied Physiology,” Dr. Phillips and colleagues discovered that strength training with light weight to failure resulted in similar muscle enlargement as heavy weight. Additionally, training with light weights and high repetitions improves muscle endurance. The research suggests that there is no real benefit to heavy weights and lower reps.
- PLOS ONE: Low-load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-load Low Volume Resistance Exercise In Young Men.
- The New York Times: Ask Well: More Repetitions vs. More Weight?
- Journal of Applied Physiology: Resistance Exercise Load Does Not Determine Training-mediated Hypertrophic Gains In Young Men.
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