Have you ever watched a bodybuilder grunt as they lift an ultra-heavyweight? After seeing the grimace on their face, you might wonder whether weightlifting is for you! However, we all need it to reduce muscle loss related to aging. We begin to lose muscle after the age of 30, and the process accelerates after middle age. In this article, David Reagan, Atlanta-native and a certified personal trainer, answers the question: do we really need to lift heavy to get results?
The principle of progressive overload states that muscles grow when you overload them. In other words, you challenge them to work more or lift more than they’re accustomed to. You don’t confront them with heavy resistance all at once, but gradually increase the challenge of your strength-training workouts. However, increasing the weight isn’t the only way to use progressive overload, you can also boost the number of repetitions, number of sets, or otherwise adjust your training to make it harder, but it all comes down to challenging your muscles more over time. Recent Studies on Muscle Gains and Lifting
What if you don’t want to tackle the heavier weights but you still want to gain muscle size and definition? A study carried out by researchers at McMaster University finds that you can. For the study, a group of healthy, young men did unilateral leg extensions using two different resistances. One group did leg extensions against a resistance equal to 90% of their one-rep max. This is a very heavy resistance equivalent to the heavyweights that powerlifters and bodybuilders use. The other group used a lighter resistance, 30% of their one-rep max.
Each group of guys did legs extensions until muscle failure, meaning the muscle was too fatigued to do any more repetitions. As you might expect, the men pushing against the heavier resistance did fewer reps than the guys pushing against the lighter resistance. However, both worked their muscles to failure. They also completed four sets of leg extensions to failure with 3 minutes of rest between each set.
To look at the effects each workout had on muscle growth, the researchers measured muscle protein synthesis afterward in each of the subjects. Muscle protein synthesis is an indirect marker of new muscle growth. The results? Both groups experienced a similar boost in muscle protein synthesis. However, the guys who lifted the lighter weights had a more sustained increase in muscle protein synthesis and the protein synthesis remained high even a full day after their workouts. Working Muscles to Failure
Based on this study, lifting lighter weights may be as effective or even more effective for building muscle as lifting heavy. The stipulation is you have to work the muscle to failure or near failure to stimulate growth. However, this approach would not be as effective for building muscle strength. Muscles build the most strength through heavy lifting since it recruits more fast-twitch muscle fibers, the kind designed for strength and power. However, using lighter weights and higher reps means you can do more total volume, and training volume is a factor in maximizing muscle growth. Training volume is a product of the weight you use and the total number of repetitions and sets.
The take-home message here is that the weight you train with doesn’t matter as much as fatiguing the muscles that you’re working. If you exhaust the muscles, they will respond by growing even if you used lighter weights. One downside to this approach is, you’ll have to do more repetitions for each set to fatigue the muscles and that takes more training time.
The fact that you don’t need to lift super heavy to grow larger muscles is good news for older people who don’t feel comfortable lifting heavy. It’s also beneficial for those with joint problems or old orthopedic injuries where the added burden of using heavyweights could be uncomfortable. Plus, lifting weights is safer when people first start out. Until you’ve mastered the form of an exercise, like squats or deadlifts, it’s better to use a lighter resistance and more repetitions. It’s easy for proper form to break down after a few repetitions using heavyweights. Vary Your Strategy
There’s no need to use a single approach when weight training. In fact, varying the resistance and rep range will keep your muscles growing. Some days, lift heavier and do lower repetitions and other days, lighten up on the weights and do more repetitions. Also, don’t lift to failure on every set as this is too taxing to the muscles you’re working, especially if you’re using heavyweights. It’s safer to lift to failure when using lighter weights. But, even if you’re lifting lighter, don’t go to failure on every set every time you train. Taking every set to failure can reduce muscle gains by boosting the stress hormone cortisol.