Have you ever walked into the free-weight area of a gym, seen the enormous barbells getting lifted, and turned right back around? If so, you aren’t alone. The idea of hoisting a super heavy weight over your head is scary and intimidating—especially if you’re relatively new to strength training. That’s why a recent study in the Journal of Applied Physiology is so exciting. Researchers found that you can get just as strong lifting light weights as you would lifting heavy weights—you just need to make sure you’re doing the moves for a little longer.
The researchers took two groups of men and had them lift weights four days a week for 12 weeks. One group lifted heavy weights and the other lighter ones. “Everyone did the exact same moves; the only difference was the load—how heavy the weights were—and how many reps they did,” says Rob Morton, a PhD candidate at McMaster University and lead author of the study. “For this study, we made sure that everyone did each exercise until they reached something called ‘volitional failure,’ which means their muscles got so tired that they couldn’t do another rep.” As a result, the group that lifted lighter weights ended up working out for a little longer—they needed to do more reps than the other group before they hit the point of failure.
Here’s the exciting part: The results showed there’s no need to pick up a huge barbell to get stronger. That’s because both groups put on an equal amount of lean muscle mass and saw the same improvements in strength. It turns out it doesn’t matter how much you lift, you just need to keep going until you can’t do the movement anymore. “By going until volitional failure, you fatigue your smaller muscle fibers and need to recruit the bigger muscle fibers—and activating all of those fibers is key to changing your muscle mass and strength,” says Morton.
How to Build Muscle Using Any Size Weight
So light and heavy weights can both help you reach your strength training goals. That’s great! Now how do you put this knowledge into practice? Jennifer Ledford, a certified personal trainer in the San Francisco area, had these tips:
Start lighter and work your way up. It’s okay to pick up a five-pound dumbbell and go from there.
Know when to go heavier. You don’t want to spend all day in the gym, so if you can do 25 reps with ease, it’s time to go up to the next weight.
Keep it light if you have joint problems. Heavier weights can put a lot of strain on your joints, so stick to the lighter weights if you have weaker joints or pain in your elbows, shoulders, knees, and hips.
Take a day off between lifting days. While you can do cardio on back-to-back days, your body needs to recover after you strength train. Rest your muscles for 48 hours between visits to the weight room, even if you don’t feel sore. If you want to lift weights more regularly, do upper body one day and lower body the next.
This article is not intended to substitute for informed medical advice. You should not use this information to diagnose or treat a health problem or condition. Always check with your doctor before changing your diet, altering your sleep habits, taking supplements, or starting a new fitness routine.