When it comes to weightlifting, people hit the gym for a plethora of reasons. Maybe you want to improve your overall health, lose weight, or cross-train for your sport.
Two of the most common workout goals are training for aesthetics, like growing your muscle size, or building muscle strength, which can both be achieved through lifting weights, says Brittany Watts, NASM-CPT, head coach at Tone House. Chances are, if you’ve ever dabbled in weightlifting, you’ve noticed some crossover between these goals—maybe your muscles are getting bigger, but does that mean they’re becoming stronger too? And vice versa?
Meet the experts: Brittany Watts, NASM-CPT, is a head coach at Tone House. Jacqueline Kasen, CPT, is a Miami-based coach, master trainer, and senior director of group fitness at Anatomy.
Ahead, trainers explain whether muscle size really equals muscle strength—and how to train to achieve your goals.
Does muscle size equal muscle strength?
In short, not necessarily. The ways you train to grow your muscle size versus muscle strength are completely different.
Muscle size, or hypertrophy, refers to the cross-sectional area of the muscle (literally how big your muscles appear), achieved by building muscle fibers through focusing on high volume, time under tension (slower, more controlled movements that hold a muscle under tension), and muscle fatigue. If you’re training to build muscle size and you have visibly large muscles, that won’t necessarily lead to actual strength gains—instead, it’s a measure of the size of your muscle fibers, says Watts.
On the flip side, muscle strength refers to the muscle’s ability to exert force, and it isn’t necessarily related to size, Watts says. One small study published in Medicine & Science in Sports and Exercise assessed 52 active men through isometric knee extension strength tests, MRI scans, and ultrasound images of their legs to determine the strength and size of their muscles. It found that muscle size had a weak association with strength.
“While larger muscles often have the potential to produce more force, strength is influenced by more than just size,” says Jacqueline Kasen, CPT, a Miami-based coach, master trainer, and senior director of group fitness at Anatomy. When you lift a heavy load, the mind-muscle connection gets involved— your nervous system kicks into gear to pick up the heavy load as efficiently as possible by recruiting muscle fibers. So someone might be super strong without having large, bulky muscles, Kasen says.
While someone might have visibly large muscles from training for hypertrophy, that doesn’t necessarily mean they can lift as heavy as someone who trains purely for strength. That’s because building muscle size doesn’t train the nervous system to handle maximal loads, Watts adds.
A 2020 review in the European Journal of Translational Myology looked at human and rodent studies on the parallels between muscle size and strength and concluded that while there’s generally a positive relationship between muscle hypertrophy (increased muscle size) and muscle strength, they are not always directly linked. Numerous studies in both humans and rats show that it’s possible to gain muscle size without gaining strength, and vice versa.
To sum it up: While hypertrophy training is about the size of the muscle fibers, strength training is about the efficiency of those muscle fibers, Kasen says. So, you can have big muscles and still not be the strongest one at the weight rack.
How To Train For Muscle Size Vs. Muscle Strength
Muscle Size
If you want to grow the size of your muscles, you likely have an aesthetic goal—maybe you’re focusing on body recomposition (like gaining muscle and losing fat) or are training for a bodybuilding competition. Hypertrophy training can also help increase your metabolism, since muscle tissue burns more calories than fat tissue, according to the National Library of Medicine, which can improve your basal metabolic rate (BMR)—the amount of calories your body needs to sustain at rest, says Watts. Training muscle size can additionally preserve muscle mass to combat age-related muscle tissue loss, Kasen adds.
Your Plan
- Weight: 60 to 80 percent of your one-rep max (the heaviest weight you can comfortably lift with good form for a single rep) or 7 to 9 on the rate of perceived exertion (RPE) scale throughout your effort. (This is a subjective measurement, on a scale of one to 10, of how hard you’re working.)
- Reps and sets: 6 to 15 reps for 3 to 6 sets
- Rest periods: 60 to 90 seconds
Train each major muscle group (shoulders, chest, arms, core, back, legs, glutes) two to three times a week with a focus on time under tension, progressively increasing volume over time. For example, if your starting point is 6 reps and 3 sets with good form, you can gradually work up to 15 reps for 6 sets. Supplementing with one to two days per week of cross-training, like cardio or mobility work, can support overall health and recovery.
Muscle Strength
If your goal is muscle strength, you’re training to lift heavier in the gym, but the benefits extend far beyond. Building muscle strength enhances functional fitness and improves your ability to perform daily tasks, Kasen says. (For example, doing biceps curls will help you carry heavy bags of groceries up stairs with ease.) Plus, strength training is especially valuable for maintaining bone density, joint stability, and functional movement, especially as you age, Kasen says.
A 2022 review in the British Journal of Sports Medicine looked at 16 studies and compared the association between muscle-strengthening activities and health in healthy adults over the age of 18. It found that adding activities for muscle strength into your routine can help reduce your risk of conditions including heart disease, diabetes, and early death.
Your Plan
- Weight: 80 to 95 percent of your one-rep max or 8 to 10 RPE
- Reps and sets: 3 to 6 reps for 3 to 6 sets
- Rest periods: two to five minutes
Train each muscle group around two to four times a week and focus on compound movements that work multiple muscle groups at once, like deadlifts and squats. When you’re ready to increase your load—with good form, of course—gradually increase the load of the weight you’re lifting, Watts says.
Adding in one to two days of cross-training per week is also “crucial for cardiovascular health, joint mobility, and metabolic conditioning,” Watts says. “Strength alone won’t cover all health markers.” Cross-training also helps prevent muscle imbalances, reduces injury risk, and can aid recovery by promoting blood flow, she adds. Just be sure to avoid high-intensity cross-training on heavy lifting days, as this can prevent proper muscle recovery.
Training just for muscle size or muscle strength both have their advantages. But “the best approach often includes a combination of both—training in a way that helps you stay strong and muscular enough to support daily life and healthy aging,” Kasen says. To find this balance, try two to three days of hypertrophy training, two days of strength training, and one to two days per week of cross-training (running, cycling, swimming, or yoga), Watts says.
And just like that, you’re ready to hit the weights.
Jordan Smith is a writer and editor with over 5 years of experience reporting on health and fitness news and trends. She is a published author, studying for her personal trainer certification, and over the past year became an unintentional Coronavirus expert. She has previously worked at Health, Inc., and 605 Magazine and was the editor-in-chief of her collegiate newspaper. Her love of all things outdoors came from growing up in the Black Hills of South Dakota.
Read the full article here
