You’ve probably heard that when it comes to developing muscle mass, heavy weights are favored over lighter weights. And if you’re simply aiming to enhance overall muscular fitness, it’s better to do a higher number of repetitions using lighter weights, correct?

As it happens, the question of what to lift and when for specific purposes is a highly debated topic in the fitness industry. Here, experts analyze the science and disclose the precise occasions when you should incorporate light weights or heavy weights in your strength training routine.

Should You Opt for Light Weights or Heavy Weights?

Despite the straightforwardness of the question, there is still no consensus on whether you should select light weights or heavy weights for your strength training workouts. Currently, the existing research on the matter presents conflicting views. A study conducted in 2016 and published in the Journal of Sports Science & Medicine discovered that when the number of sets is the same, training with heavy weights may be optimal for maximizing muscular strength (referring to the greatest amount of force a muscle can generate), whereas training with moderate weights may be ideal for increasing muscle size.

However, the findings published in the Journal of Strength & Conditioning Research in 2015 diverge from these conclusions. In this study, a small group of men who were experienced in resistance training were assigned different exercises using either a lower weight for 25 to 35 repetitions per set or a higher weight for just eight to 12 repetitions per set. At the conclusion of the study, the participants who used heavier weights for fewer repetitions displayed significantly greater improvements in back squat strength and the maximum weight they could lift for the bench press. On the other hand, those who used lighter weights for a higher number of repetitions demonstrated greater enhancements in upper-body muscular endurance. Remarkably, both groups experienced similar increases in muscle size, as stated by the researchers.

Furthermore, it may not solely be about choosing between light weights or heavy weights, but also about working the muscle until complete failure or exhaustion, according to Michele Olson, Ph.D., F.A.C.S.M., C.S.C.S., a senior clinical professor at Huntingdon College in Montgomery, Alabama. “If you continue an exercise until you are unable to perform another repetition with proper form, the weight’s heaviness becomes less significant.”

Consider a study published in the Journal of Applied Physiology. It determined that regardless of how heavy or light people lifted, they experienced similar increases in strength and reductions in body fat when they lifted to the point of near failure. This concept of working until failure, regardless of the weight being lifted, is not a new idea, adds Olson. Additionally, the American College of Sports Medicine advises individuals to choose a weight that feels like an 8 out of 10 in terms of difficulty, perform three sets of eight to 12 repetitions with proper form, and ensure that the final repetition of each set feels challenging to complete.

TL;DR: Opting for a substantial weight could assist in enhancing your muscle strength, while a moderate weight may contribute to the development of your muscular endurance, as indicated by research. However, there is uncertainty regarding the most effective load for increasing muscle size. Nevertheless, experts and research suggest that lifting until you are close to reaching your limits, regardless of the weight you are using, can play a crucial role in boosting both muscle strength and size.

4 Factors to Consider When Engaging in Weight Lifting

The ongoing debate between using light weights versus heavy weights is not yet settled, and load is not the sole aspect to take into consideration. “Every aspect matters: the number of sets, repetitions, tempo, rest periods, and exercise selection all determine the outcomes you achieve from your weight lifting,” states Lawrence Betz, C.S.C.S., the former director of the Brooklyn Athletic Club. So, apart from fixating solely on light or heavy weights, what other points should you keep in mind while engaging in weight lifting?

Familiarize Yourself with the Sensation of ‘Heavy Enough’

As a general guideline, if you are using an appropriate load during an exercise, ideally, the last one or two repetitions of a set should feel exceptionally challenging to complete while maintaining proper form, according to Jessica Matthews, D.B.H., M.S., an associate professor and program director in the College of Health Sciences at Point Loma Nazarene University. If you effortlessly complete your final repetition without exerting much effort, consider it an indication to increase the weight you are using.

Reevaluate the Definition of a ‘Light’ Weight

Olson suggests that most individuals would likely benefit from reevaluating their perception of what qualifies as a “light” weight. For an average woman weighing 145 pounds, a maximal squat would typically range between 130 and 135 pounds. Hence, in this context, utilizing a “light” weight would entail performing around 25 to 30 repetitions while holding dumbbells weighing 15 to 20 pounds. Olson further explains, “Many women regard a dumbbell weighing approximately 10 pounds as heavy.”

Prioritize Volume

“The commonly accepted viewpoint has always been that volume (frequency of lifting and number of repetitions) is the most crucial factor in achieving results from weight lifting,” explains Dan Roberts, a well-known strength and conditioning coach, trainer, and creator of the online fitness plan Methodology X. “No one suggests that you need to lift exceedingly heavy weights in order to become stronger.”

Therefore, rather than exclusively focusing on lifting heavy weights all the time, it is equally important to concentrate on lifting an adequate amount, he advises.

Keep a Watch on Your Technique

The manner in which you’re actually lifting the weights is also crucial, says Betz. Ensure that you’re not attempting to lift such a significant amount that your technique becomes poor, as this could potentially lead to strains and injury and reduce the effectiveness of the exercise. Regardless of how heavy you’re lifting, incorporate suitable periods of rest as well. Otherwise, you’re simply on your way towards additional injury rather than gaining more muscle. Ouch.

Thanks for your feedback!