Whether you do chest and back exercises together or separately, lifting weights for 8 weeks will make you stronger on the bench press and lat pulldown.

If you're a regular gym-goer, doing workouts that group similar muscle moves together or alternate them doesn't seem to make a difference in how much stronger or bigger your muscles get after 8 weeks.

If you're a regular gym-goer, doing workouts that pair similar muscle groups together (like two push exercises) or alternating push and pull exercises both work just as well to build strength and muscle size over 8 weeks.

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.

Whether you do similar muscle groups together or alternate them, you end up lifting about the same total weight over 8 weeks.

If you're already strong and lift weights regularly, doing 10–15 hard sets per muscle group each week for 2 months will make you stronger and add a little muscle — whether you train your whole body every day or just once a week.