Browse evidence-based analysis of health-related claims and assertions
Your muscle fibers don’t get longer with one training method over another—whether you go to failure, use pyramids, or stick to the basics—as long as you do the same total amount of work.
Causal
No matter if you use a pyramid, go to failure, or stick to a normal routine, your muscle fibers don’t change their angle or how they’re packed together any more with one method than another—when you do the same total work.
When people who already train hard do different kinds of leg workouts—pyramid, failure sets, or regular sets—all of them get about the same boost in how much weight they can lift in a leg extension machine, around 17%.
Whether you lift weights using a pyramid, go to failure, or stick to a standard routine, if you do the same total amount of work, your leg strength improves by about the same amount—around 25%—after 12 weeks.
When people who already lift weights train with different methods—like starting light and going heavy, or doing sets to failure—all of them get about the same muscle growth if they do the same total amount of work.
Just because short rests make you feel more tired and your muscles burn more during one workout doesn’t mean they’ll make your muscles bigger over time—you’d need to study people for months to know that.
Descriptive
You can make your workout feel harder and your muscles burn more by resting less between sets—but you can still lift the same total weight without getting weaker.
Even if the air has the same oxygen level, being at real high altitude makes your body respond differently to weightlifting than breathing the same air through a mask—your muscles get more oxygen, you produce more lactic acid, and your heart works harder.
After lifting weights, your heart rate comes back down to normal at about the same speed whether you rested 1 minute or 2 minutes between sets, or whether you trained at real altitude or with a mask.
When you breathe oxygen-poor air through a mask for only 5 minutes before lifting weights, your blood oxygen level drops more than when you’re at real high altitude—even if the air has the same oxygen content.
Whether you rest 1 minute or 2 minutes between squat sets, your muscles get about the same amount of oxygen during the exercise, even if you're at high altitude or breathing normal air.
People feel much more tired after doing weightlifting with only 1 minute of rest between sets than with 2 minutes of rest, no matter if they’re at high altitude or breathing oxygen-poor air.
Whether you rest 1 minute or 2 minutes between sets, or train at real high altitude or with a mask, you can still lift the same total amount of weight without losing strength.
Even when the air has the same amount of oxygen, breathing it through a mask at low pressure makes your body produce less lactic acid and keeps your heart rate lower during weightlifting than being at real high altitude.
Breathing air with less oxygen through a mask (simulated altitude) makes your muscles get less oxygen during exercise than being at real high altitude, even when the oxygen level in the air is the same.
Taking less rest between sets of weightlifting makes your body work harder, raises your heart rate, makes your muscles burn more lactic acid, and feels much more exhausting.
If you're already someone who lifts weights, doing light weights twice a week until you can't do more reps can make your muscles bigger and stronger in just 8 weeks.
For people who already lift weights, it doesn’t matter much if you rest 30 seconds or 2.5 minutes between sets of light weights — you get the same muscle growth and strength gains either way.
Quantitative
You can get stronger and bigger muscles by lifting light weights until you're exhausted — even if you never lift heavy, which challenges the old idea that heavy weights are required.
Mechanistic
Whether you rest a short or long time between light weightlifting sets, your body releases about the same amount of growth-related hormones right after the workout.
Resting 30 seconds between sets of light weights builds your arm and leg muscles just as well as resting 2.5 minutes — at least in people who already train regularly.
If you're already trained, doing light weights with short or long breaks between sets gives you about the same strength boost in your chest and legs after 8 weeks.
Even though your body releases similar growth hormones after light workouts whether you rest a little or a lot, you still get stronger and bigger muscles either way.
Whether you rest 30 seconds or 2.5 minutes between sets of light weightlifting, you end up with about the same muscle growth and strength gains after 8 weeks.