Do You Need Heavier Weight or More Reps to Build Muscle Mass?

It’s a great question- should you lift heavier weight or more reps to gain muscle mass? Many opinions float around on this topic. Like many of my posts, before we dive in, I want to recenter your focus on your individual goal. If you truly are looking to build muscle mass, you need a specific approach to get you the results you are looking for. The answer will differ if your focus is to get more toned, develop a certain look, increase endurance, gain strength, or any other goals you might have.

Here’s my quick thought on it. If you want to gain mass, it helps to focus on reps. The volume of work is a key component to lifting for mass, especially if you are naturally skinny. That’s not a hall pass to skip heavy weights. Please don’t use that as the excuse to stop challenging yourself in training. Keep reading below, and I’ll explain why I advise skinny people to focus on reps instead of heavy weights.

Heavier weights build your ego, not muscle mass

I know how it feels to walk into a gym and put a pair of 10 pound plates on the ends of a bar to bench. It’s embarrassing. I would rather at least slap some 45 pound plates on each side and push for a rep or two, so that everyone sees what you can do. Of course, I am not thinking about how little I’m actually gaining by doing this. How I think others see me or how much I hype myself in the moment matter more than really making any progress. Heavy weights can significantly stall your progress, because it screws up your form.

Think about performing a squat without actually reaching the point where your thighs are parallel to the ground. That lack of a full range of motion is cheating your potential to build muscle mass. However, if you are using a weight that’s too heavy for you, then you will struggle to ever complete a rep with full range of motion. This is the result of ego lifting. You are also risking injury, because your body is trying to do anything to get the weight back up. So, instead of staying strictly in proper form, you will start to cheat and move in ways that put you at risk. Injuries lead to time away from training, which does not build muscle mass.

Start light and see progress quickly

You’re not impressing anyone by lifting weights that you can’t handle. It’s obvious that when you’re struggling, look awkward trying to force the weight up. The biggest sign is when you haven’t made any progress over time. Instead, benefit from starting off with light weights that allow you to perform 10 reps per set. This will have a significant boost to your confidence quickly. Sure, maybe it’s not as cool as pushing heavy plates today, but you’ll start to increase the weight on the bar each week. That will give you the dose of accomplishment you need to keep going. With the German Volume Training that I recommend, when you can complete 10 sets of 10 reps with a certain weight, you increase that weight by 10% the next time.

Quickly, a 65 pound bench increases to 75, then 85, then 95 and more. Sure it was embarrassing to start at 65, but in a short time, you are now pushing two 25 pound plates on the bar. That’s a lot more impressive than for you to spend the rest of the year continuing to press 135 pounds for a few poorly performed reps, with no ability to move up.

Also, light weights give you a chance to get the fundamentals right. Get your form correct, so that when you are capable of lifting heavy, you can do it the right way. If the weight is too much for you to handle, there’s no way you get the form right. You’re too busy just trying to survive. Your back curves, your shoulder roll forward, and you strain your neck just trying to get through the moment. Lighten the load and get the fundamentals right first.

More reps increases your Time Under Tension

Time under tension is the central idea behind hypertrophy training and specifically German Volume Training. To build muscle, you have to stimulate the muscle to grow. Cranking out reps as fast as possible can work for powerlifting, but it’s not the best way to optimize your routine for size. When you increase the weight on the bar, you can naturally only lift it less times than if you decrease the weight. Also, heavy weights are more likely to lead to your body jumping into survival mode and cheat to get the weight up. Usually, this includes rushing through a rep, bouncing the weight off of your body, or swinging to make it easier.

Control the weight. Don’t let the weight control you.

However, there has to be a compromise between maximizing time under tension and making sure you are actually challenging yourself with a meaningful weight. See my post discussing the exact tempo that I found worked best for me when training for massive gains. The way I think of the weight is this- What’s the most I can lift, if I have to complete 10 sets of 10 reps, with 60 seconds of rest, following a 1-0-1 tempo?

The way I think of the weight is this- What’s the most I can lift, if I have to complete 10 sets of 10 reps, with 60 seconds of rest, following a 1-0-1 tempo?

This means I still emphasize more reps to build muscle, but it keeps me honest so I don’t fail to challenge myself.

You have to actually lift the heavy weights, not just touch them

Let’s say that I can bench 135 pounds for a few reps, but it’s a big struggle. If I set out to complete 10 sets of 10 reps, and I fail 5 reps into set 1, I can’t claim credit for the rest of the workout. The reality is that I’ve only moved the weight 5 times.

Instead, if I decide to drop the weight and the ego and bench 95 pounds, I can do more volume of work. In this example, even if I fail from time to time on each set, I will probably still end up having done 70-80 reps total. Lifting 95 pounds 70 times in a controlled fashion takes a lot more effort than lifting 135 pounds 5 times. That work is what will trigger your body to build muscle mass.

This is why it’s way more important, especially as skinny people, to think about optimizing for more reps than heavier weights. There’s a balance, but this is how I recommend you think about your training.

Thoughts? Questions? Please let me know in the comments!