When you're strength training, there's more to consider than reps and how much weight to pick up. Another important factor in improving: rest between sets.
The amount of break time you take determines how your muscles adapt to the movement, says Carwyn Sharp, Ph.D., chief science officer for the National Strength and Conditioning Association.
"Matching rest periods and intensities places the appropriate amount of stress on the muscles and their energy systems," he says.
Besides working your muscles in different ways, the breather you take between exercises correlates to injury prevention.
"If you wait too long to move your muscles again, they become cold, which increases the risk of injury due to muscle damage," says Peter McCall, exercise physiologist and American Council on Exercise trainer. "On the other hand, if you don't rest long enough, your body can't replenish the muscles' energy efficiently, so you're exercising in a fatigued state. This can lead to poor form and therefore injury."
Reach your fitness goals while still feeling 100 percent by following this goal-based breakdown.
Editor's note: For much of the advice below, it's helpful to know your 1RM, or one rep max. That's the maximum amount of weight you can lift and perform one repetition before you're fatigued. If you aren't sure of your 1RM, here's how to calculate it.
If your goal is to get stronger, faster...
A recent study found that when performing a three-rep move (that means you'd be pumping heavy iron—85 percent or more of the max weight you can lift), you should rest a minimum of two minutes between sets. This will maximize your strength gains. Even better, waiting three minutes will help lower your perceived exertion levels or how hard you think you're working, while still boosting your stamina.
"The rest between sets determines your ability to sustain the heavy weight for subsequent sets," says Estevao Scudese, study author and associate researcher at Federal University of Rio de Janeiro in Brazil.
Your muscles need this time to prepare for the next set of moves so the energy compounds, known as phosphagens, can replenish, says Amanda Butler, a certified trainer and instructor at The Fhitting Room in New York City. Without giving them the chance to refill, you'll feel too fatigued too fast.
More From Greatist: When Should You Lift More Weight?