Is It Better To Use Heavy Or Light Weights? – Women’s Health

Weight training is like eating your veggies: You know it’s good for you, but with so many varieties to choose from, how do you pick what’s best?! Is lifting heavy the way to go? Or maybe working with fewer pounds for longer amounts of time? Perhaps somewhere in between?

With more ultra-popular fitness classes than ever on both ends of the spectrum (barre on one side and CrossFit on the other), the conversation gets even murkier. Picking up something is better than nothing, says Hannah Davis, CSCS, creator of Body By Hannah. But ultimately, the weight you should reach for really depends on your intended result.

Let’s back up. There are essentially two big-picture ways to think about strength training: high-weight, low-rep or low-weight, high-rep. (Try saying that 10 times fast.)

In the high-weight category, one approach is going heavy—say, deadlifting your body weight three to five times. Or you can use moderate loads (approximately 60 to 80 percent of your one-rep max, according to the American College of Sports Medicine) for 8 to 15 reps.

The other strength-training school of thought says to opt for much lighter weights and complete 20, 30, or as many reps as possible (AMRAP) in a set amount of time, usually 45 to 90 seconds.

Tyler Joe

Returning to the burning question: What’s the best way to reach your goals?

• Why low weight is very awesome for beginners:
  • Yeah, yeah, you know you shouldn’t go from zero to bench-pressing 150 pounds overnight, but if you’re trying out a new exercise or workout, lighter weights are your best friend. “The key is understanding the technique and range of motion before adding on weight,” says exercise physiologist Rachel Straub, CSCS, coauthor of Weight Training Without Injury. Lower weights can help you master your form, which will help you get more out of the move and prevent injury. Then you can either up your reps or increase the weight for more of a challenge.

• If you want to sculpt visible muscle…
  • “I personally go for a moderate to high weight in the 10-rep range, but some people prefer training to fatigue with lighter weights,” Straub says. Both techniques are effective. No matter which one you choose, Straub and Davis both agree that to create definition, this rule is key: The last two reps of each set should feel like a struggle. That means you’re actually challenging yourself and not just going through the motions.

• What about getting stronger in general?
  • Yep, strength and muscle aren’t synonymous. “Strength is relative,” says Davis. “If you’re not picking up progressively heavier weight, then you’re not building it.” (You need to continuously load your muscles to build new fibers.) For this, heavy lifting reigns supreme.

Tyler Joe

Are low-weight/high-rep combos better for cardio, or heavy-weight/low-rep ones?

No matter which weights you grab, if you minimize the rest between sets, you can keep your heart rate up, says Straub. But doing so can be tough with mega-heavy loads. By lifting lighter for longer instead—like 20 to 30 reps for one exercise—it’s easier to cross the aerobic threshold (using oxygen for energy), says Davis.

Straub even recommends turning it into a training circuit, moving from one drill to the next with short breaks. Aerobic strength training also goes hand in hand with building muscle endurance—a muscle group’s ability to sustain repeated contractions for a period of time, which is especially beneficial for runners, cyclists, and swimmers who need to go the distance during workouts.

Tyler Joe

Which weight-lifting option is better for staying healthy long-term?

Both high-weight, low-rep and low-weight, high-rep methods are fair game for staying in good shape over the long haul, says Davis. But when you’re talking really, really few reps with heavy loads—like powerlifting—there is a greater risk for injury. Straub adds that if your technique and flexibility aren’t solid, then you may run into issues here, whether you’re a beginner or not. “I see people with poor posture and alignment at the gym, trying to pile on heavy weights, but they’re not getting the benefits,” she says.

To remedy this, she recommends scaling back in size to ensure good form. Once you’ve mastered that, consistency is what matters. Think: lifting challenging weights three to five times per week. Doing so keeps your muscles and frame strong, according to research. That’s because bone mass peaks for most women in their late 20s, and density starts to dwindle in your early 40s. So strength training throughout this time will help support you.

The bottom line: In the end, if you’re lifting any weights, you’re already killing the game. And the great news is that whether you’re opting for high reps or low, you’ll see results. Whichever you choose, just be sure to pick loads that feel challenging (the last couple of reps should be a struggle), and continue to add more volume, Davis says. “That can mean increasing weight or reps.”

This article originally appeared in the October 2019 issue of Women’s Health.

Fitness & Wellness Editor Kristine Thomason is the fitness & wellness editor at Women’s Health, where she edits, writes, and helps oversee the food and fitness sections of the website and magazine.