If overweight guys in their mid-30s do a short but intense weight training routine three times a week for six weeks, they can boost their leg strength by nearly 27%—showing you don’t need long workouts to get stronger fast.

If young guys stick to the same exercises every time they work out for about two months, they get stronger in a specific leg test than if they keep switching up their routine.

If you're already strong and lift weights, training each muscle group either once or five times a week for eight weeks will give you about the same strength gains on the bench press, squat, and row.

Doing slow, low-effort weight training three times a week for 12 weeks can make your thigh muscles bigger and stronger, just as much as doing fast, high-effort weight training.

If you're a guy who already lifts weights, doing 4 workouts a week for 8 weeks will make you way stronger—adding about 25 pounds to your squat and 10 pounds to your bench, whether you stick to the same routine or mix it up.

Doing gentle strength exercises slowly and steadily twice a week for 12 weeks makes older adults' knee muscles stronger.