Heavy vs Light Weights for Muscle Growth (WHICH WORKS BETTER)

If you have ever wondered whether to use heavy vs light weight to build muscle, you’ve come to the right place. In this video, I am going to explain to you whether you need to use heavy weight or light weight in order to build muscle and when to use both in your training. You might think one is better than the other in your pursuit to build muscle, but this might be a flawed way of thinking and you could be leaving gains on the table.

The video starts off with a quiz where I want you to leave your answer in a comment below. In this side-by-side of Jesse performing the dumbbell bench press, I want you to make a guess as to which clip shows Jesse building more muscle. Is it when he uses the heavy weight or is when he uses the light weight? In the heavier set, Jesse is using a 8-10 rep max and in the lighter set, he is using a 20-30 rep max. Clearly he hits failure earlier in the set with the heavier weight and he is still grinding out reps with the lighter weight. Once you have your answer, leave a comment thinking which one builds more muscle.

My answer? Jesse is building muscle with both the heavy weight and the light weight.

If you answered like me or even chose lighter weight as the winner, you would be wrong according to a comment left on a recent video. The commenter believes that you cannot build muscle with anything less than 80% of your one rep max and that using lighter weight is a waste of time.

This is where I have an issue. Research has pointed out that you can build muscle in any rep range as long as the intensity of the set is adequate. At heavier weights, this effort and intensity does not require you to achieve failure simply because the amount of tension on the muscles is greater due to the heavier weight. However, to achieve the same adequate tension required for muscle growth when using light weights, the intensity has to be much greater. That means as the number of reps you perform goes up, the closer to failure you have to go.

See, when it comes to building muscle, tension is the driving factor. With heavy weight, tension is achieved simply by the amount of load used. With light weight, there is far less tension outright, thus to equate it to heavy weight, training to failure is required.

It doesn’t stop there, however. There needs to be an understanding of what failure is within these rep ranges. In low rep ranges with heavy weight, there is no subjectivity. You either can lift the weight or you cannot. When using moderate weight, especially in the 8-12 rep range, failure becomes slightly more subjective. You will probably have a good indication of failure, but in many cases, you might be able to squeeze out another rep or two.

When using light weights and the amount of reps you are performing gets higher, such as in the 20-30 rep range, failure becomes extremely subjective. You might stop the set when your muscles begin to burn, thinking that it’s become too uncomfortable to perform another rep. However, I would argue that this is where your set is just beginning. If you decided to revel in the burn and push past that uncomfortable feeling, you would see that you are capable of quite a few more reps. This is where the magic happens.

I like to say that if you are using light weight and that you give up the set when the burn starts, you’ve wasted not only your set, but your time. The most productive, growth-inducing reps occur when the burn starts. As a matter of fact, those light weights can produce just as much muscle growth as the heavy weights as long as the set is taken to true failure.

As a matter of fact, you should explore training in all rep ranges as we know that heavy tension (in the form of weight) will only produce gains for a limited amount of time. Moderate rep ranges are great for eccentric overload, but with the packaged soreness that comes along with it, there needs to be something else that allows you to train hard. This is where metabolic training comes in thanks to the use of light weights.

But now comes the question; when should you use light weight and heavy weight in your training?

Continue watching the video to see the other scenarios where light weight and heavy weight should be used to build muscle.

For more videos on how to build muscle be sure to subscribe to our channel here on youtube via the above link and turn on your notifications so you never miss a video when it’s published.

[athleanx]

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[carbon_ceramic]

I remember in one of your videos..."dont count the reps, make the rep count!" That is the most concise advice I have ever seen on YouTube.

[thexclusivek]

I took your advice from last video. Lowered the weight focussed on mind body connection & SLOWED down the reps. That tension was amazing. Never felt better.

[ChildPsychologist-mr]

You are so RIGHT!!! i am 73 years young. About 7 years ago, I was diagnosed with an aortic aneursym. My cardiologist said i had to stop heavy weight training. I consulted with an aortic specialist who told me i can use light dumbbells and do high reps. I took his advice to "heart." I do 6 different upper body exercises for 200 reps each (1200 total) with light dumbells. The results have been amazing. A recent body scan showed 18% body fat and tons of lean muscle mass. The trainer who interpreted my scan said it was "phenomenal" and that she has "never seen anything like it " in my age group. Thank you for confirming my experience!

[Vusseyv]

In 40 years of gym I learned more about what I should and shouldn’t be doing from Jeff in the last 6 months than the previous 39.5 years. Cheers!!

[Biking]

One of the few people to discuss and properly explain the challenges of listing over 50. it is the first time I have watched this channel, been lifting for 45 years, and learnt something today. Thank you. JP

[lindaabraham]

My opinion: the rep you have to be most concerned about is the one that is going to injure you. Pick the weights up carefully and correctly. Start light. Start few. Build slowly. For me (age 71, female, 102 lb) that means no more than 3 pounds, 8 reps, 3 sets. That is enough to keep you stronger. If you did nothing but that every day from a young age, you would still be more fit than 90% of the people my age. But the most important thing is, don't hurt yourself.

[superninja]

I have a heart condition that my cardiologist wants to limit my lifting to 15+ rep weights I’ve been on that for multiple years now and watching Athlean-X has helped me work around that. You have truly helped me and I’m certain many many more people. Thank you Jeff and Jessie and any other AX family!

[natman]

44 yr old Yorkshireman here Jeff, watching you're vids for years, usually with a beer in my hand thinking "I'm gonna start doin some of this soon" the "soon" came 4 months ago when I binned off the beer, dropped 2 stone, dusted off my bench and dumbbells, following your dumbbell only workouts, and seeing some real gains, not just in strength and my t-shirt fitting better but also with in myself... You're a true gent mate, Jessie too... Thanks for all that you've done lads..! Appreciate it..! A lot..! Peace..!

[michaelbell]

This guy is best exercise guy, out there.
He explains everything so well. Keep up the good work Jeff.

[janselperezmartinez]

Sir Ive been watching your videos for more than 6 years now. You know well your material by years of personal experience and researching scientific data. Dont let the people below your level of skills, professionalism and lack of acknowledge give you hard time. At the end of the day they’re just looking for attention to entertain their depressed boring ass life’s. Keep it up Boss. And thanks for all the info you provide us.

[Csailor]

I’ve found that I get the best results with a moderate weight, Mentzer style approach. I’m an injury prone guy, especially when I lift heavy. Since changing to the above approach, zero injuries. Solid gains.

1-2 vicious sets allows me to wreck the muscle without having to put a ton of force through it—and the tendons specifically.

For me, nothing kills gains like injuries.

[KiyoTheGringo]

I’ve been watching your vids since freshmen year in high school in 2018, and now it’s 2024, keep up the good work 👍

[renaissanceman]

let me save you 12 minutes : it depends.

[larrysmith]

Let me make this straightforward and simple, having worked out with weights for 50+ years, built quite appreciable levels of muscle and strength naturally (350x19 squat, 525 max deadlift, 220x15 and 250x7 bench—all at around 205-215 pounds), and now continuing to work out at age 71, as you get older, your joints will appreciate the use of higher rep ranges, such as 12-15, 15-20, and 20-25. Just make sure you take it to within 2 reps of failure on a regular—not constant—basis. This will work quite well for maintaining and even increasing muscle mass as you age. Period.

[paulscheufler]

Love that discussion. It's particularly meaningful for me because I'm in my 70's and just getting back to weight training after a 40 year layoff.

[lewconsiglieri]

As a new member of the septuagenarian club, I appreciate the advice on how to break up workouts into light, moderate, and heavy. A year into steady lifting, I’ve put on 25 lbs of muscle and dropped 10% body fat using your recommendations for best exercises and diet. Us older guys really worry about damaging joints. Thanks, Jeff.

[christinarumble]

About a month ago I suffered from a subarachnoid hemorrhage while I was bench pressing heavy. I was in shock: I couldn’t believe this happened to me being a healthy 37 year old fitness trainer in all. My neurosurgeon suggested I use lighter weights with more repetitions going forward. Breathing and form are overlooked in the fitness industry today, No matter how heavy or light, form and safety must be prioritized. Everyone's fitness journey is so individualized: There is no one size fits all. I am a fitness trainer and I have been watching this channel for over a decade. I have become a successful coach because of this channel! I love the fact that Jeff encourages all three types of training and the benefits that follow. Again, breathing properly and correct form are crucial no matter what the style of training.

[danqodusk]

Totally agree! Working out with heavy, medium and light weights in varying rep ranges seems to be common sense for getting the most benefits from lifting.

[Jordan-tged]

I appreciate all your videos because ive had many injuries in the past that made me never want to lift weights. I just started two months ago and have been using your advice and i feel no pain 😄