You’re not going to like this one. We have a way to build muscle fast, but it doesn’t let you go heavy, it burns like hell, and it’ll leave you sore for days. Still want to try it? It’s called “intra-set isometrics,” and it means holding the contracted position of a rep for time, interspersed with normal speed reps. Sprinkle it into your back workouts as described below—just be prepared for some pain.

How to Do It

  • Set up to perform a wide-grip seated row, and row the weight to your sternum. Hold for five seconds, then perform five normal reps. Hold the last one for another five seconds. Repeat the process four times total, until you’ve done four five-second holds and four mini sets of five. After all this (the entire set should take about a minute to complete), you can set the weight down.
  • The point is time under tension. The longer your muscles work, the more the body gets the message that it had better build them up to handle the stress. Of course, time isn’t the only consideration— otherwise, all marathon runners would have big legs. That’s where tension comes in. Combine long sets with moderate loads and you’ll get your muscles growing fast.

Other Options

Intra-set isometrics also work well for these muscle groups.

Chest

On the dumbbell bench press, hold the weights at the bottom for five seconds. Let the weight stretch your pecs— squeeze as you hold, then press up for five reps. Repeat.

Legs

Perform leg presses and hold the bottom position for five seconds. Don’t go below where your knees are bent 90 degrees. Now press up for five reps. Repeat.