Resistance training is crucial for building muscle mass, but you’ll get very different results if you lift light or heavy weights.
Resistance and Strength training is beneficial not just for aesthetic results but also for your overall health and longevity. One main issue is whether you should lift heavy weights with a low amount of reps, or light weights with more reps.
Example: Low weight training might mean doing three sets of 40 bicep curls with a 2kg dumbbell, whereas high-weight training might be three sets of five bicep curls with 14kg dumbbells.
Lifting light may help you build a lean physique
Two popular workout classes of the moment are spinning and barre, both of which often incorporate work with light weights.
Low weight and high repetition training is fantastic for those looking for defined and lean muscles without bulk.
Generally speaking, heavy weight training is geared toward adding muscle mass, whereas high repetition training creates longer-looking muscle as less power is needed and the entire length of the muscle is used to create each contraction.
With high repetition training it creates a lactic acid burn on the muscle groups of focus creating a hormone reaction that occurs over the few days post-workout.
Ultimately, it is working out to the point that your muscles are beginning to burn and shake, which is commonly what happens with high repetition and low weight training. Sticking to low weights but working at a high rep rate so your muscles end up shaking could lead to burning more calories afterwards, but that’s not the only positive. Light weights cause fewer injuries than heavy ones
Working with light weights allows you to perform movements through your full range of motion properly and precisely . Plus, the risk of injury is much lower.
As we age, we can develop joint problems and this can also be exasperated by the wrong kind of training. Using lighter weights and incorporating longer reps will only empower the body, not hit it abruptly.
Lifting heavy will help you build strength
If you want to build bulging muscles, however, lifting heavy is the way to go, which means choosing weights so heavy you can’t do very many reps at a time.
Higher loads and lower reps produce strength gains. However, this doesn’t mean that by lifting heavy you’ll immediately start resembling a body-builder, and you’ll only build muscle if you’re in a calorie surplus — ie. consuming more energy than you’re burning.
If your goal is simply to improve your body composition, performing 3-4 sets of 8-12 reps per exercise — you need to choose a weight that allows you to do that, but also feel pushed.
Aesthetic changes are, broadly speaking, about reducing body fat in relation to lean tissue, so aim to produce a hypertrophy response whilst manipulating calories (surplus to gain muscle, deficit to lose fat). For this hypertrophy response, you need to be lifting heavy enough weights.
What does the science say?
In 2012, a study by McMaster University was undertaken to compare the training effects of light weights to heavy weights in young men.
The researchers tested the effects of performing leg extensions with either light (30% of 1 rep max) or heavy (80% of 1 rep max) weights over a 10 week period.
Interestingly, the researchers found that both heavy and light loads increased muscle size equally.
The key is that both loads were lifted to exhaustion. That means the 80% group was lifting a weight that made them fatigue after about 10 repetitions, while the 30% group was lifting weights that tired them out after about 35 repetitions.
What this tells us is that, as long as each set is taken to muscular fatigue, the load lifted isn’t as important as the maximal effort applied for building muscle. This is because all muscle fibers will be recruited as a load is repeatedly lifted to failure.
While the researchers found both techniques were equally efficient at building muscle, they also discovered that for building strength, the 80% load produced superior results.
For building strength, it is better to lift heavier weights because the heavier loads train your nervous system to be able to recruit more of your muscle cells to produce more force more quickly, something that a light load will not duplicate.
So in general, one would be most likely to realize the best benefits of muscle and strength-building by repeatedly lifting heavier loads (80%+) to the point of near-fatigue (6-10 reps, but leave a little something in the tank) over time, as this could be done with a much lesser likelihood of inducing burnout.
There are pros and cons of both
There are undeniably pros and cons to both ways of resistance training.
Training with low weight and a high number of reps generally means a shorter recovery period between workouts, along with shorter rest periods between sets. The number of calories burned is likely to be higher and there’s less pressure on joints.
On the flip side, training this way is likely to take longer to build bigger muscle and you’re not likely to improve your strength massively. Whereas when lifting a higher weight with lower reps, you’ll definitely see your strength improve, along with bone density and a greater fat loss. The cons of this type of training are that you’ll need a longer recovery period for the muscle group in training, your workout is likely to be longer, and you’re placing joints under a lot of stress.
How to get results from your weight training
Which training method you choose really depends on what you’re hoping to achieve, what works for you, and just what you enjoy. What’s key, however, is that you create what’s known as progressive overload — this means either increasing weight volume or number of reps over time, intensity or frequency or exercising techniques.
However, progression will not always be linear — there is a point at which you will not be able to perform more reps or add more weight.
Both heavy and light weights will help you build muscle. Ultimately, training with either light or heavy weights is going to be beneficial, or you can mix it up by incorporating both into your regime. Just make sure you work hard enough that your muscles start to fatigue .
The most important thing is the understanding that resistance training is the key to pretty much every training goal.
Reference and excerpts from :
https://www.insider.com/how-lifting-heavy-or-light-weights-affects-the-body-in-different-ways-2019-3
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