Drop sets can help you build muscle in half the time, new research suggests. Here's how to do them.

• A drop set is a workout technique that involves reducing the weight load so you can keep exercising.
• Adding drop sets to your workout can help you build muscle and strength faster, research suggests.

Want to build muscle but are short on time? A technique called drop sets may be ideal for making gains without putting in long gym sessions, new research suggests.

In a drop set, you start an exercise with a moderate to heavy weight and then periodically reduce the weight so you can squeeze out more reps without resting.

Drop sets can lead to the same muscle gains as traditional weightlifting workouts, but in half or even a third of the time, according to a study published last month in Sports Medicine Open.

The research confirms what personal trainers and fitness pros have long known and loved about the muscle-building power of drop sets, said National Academy of Sports Medicine master trainer Andre Adams, who was not involved in the study.

"I think almost anyone can really get some benefits out of it. We're focusing on increasing work capacity at the same time as building strength," he told Insider. "It's definitely going to lead to muscle growth."

The most recent research analysis on drop sets, from Nord University in Norway, included six studies and a total of 142 participants, mostly men, ranging in age from 19 to 27.

But drop sets can be useful for a wide variety of people, from gym newbies to experienced athletes, and in many different exercises, according to Adams. They also have more advantages than just building muscle — drop sets can improve strength, help burn more calories and even boost your heart rate for some aerobic benefits, too.

Drop sets help challenge your muscles to boost gains in less time

A typical workout style involves performing up to 10 exercises, doing two to four sets of up to 12 reps of each, and resting a few minutes between each set.

The new study, from Nord University in Norway, found that these workouts did lead to muscle gains — but drop sets worked just as well, and required half the time in the gym (or even less) to complete.

A basic principle of fitness called progressive overload helps explain why drop sets are so effective, according to Adams. If you want to gain muscle and strength, you need to put enough stress on the muscle tissues, combined with enough rest, that they break down and then adapt by building back bigger and stronger.

"It's very important to place enough stimulus on the muscle during each set, because you're trying to force an adaptation," Adams said.

There are three major strategies for promoting muscle growth, he said.

Mechanical tension, or heavy weight, uses a lot of force to stress the muscle.

Another type of muscular training is metabolic stress, or the physiological reactions producing energy and by-products like lactic acid inside the muscle tissue. It involves a lot of time under tension as the muscles are working.

Finally, muscular damage, or micro-tears in the tissue itself, can also stimulate growth — a common way to cause this is a lot of volume, or high-rep workouts.

Drop sets uniquely involve all three types of muscle training in a single workout, according to Adams.

The other advantage of drop sets is that you can efficiently work up to or near muscle failure, which can help make sure you're taking on enough of a challenge to see results.

"When there's a stronger adaptation, the muscle tissue will grow back stronger," Adams said. "When you get down to the end, you feel like you're on, you've got all that lactic acid, and then at the last rep you know you've really exhausted the muscle."

However, it's important to maintain good form, especially as you get tired, to make sure you're working the proper muscles and to reduce the risk of injury.

How to incorporate drop sets into your workout to build muscle

A common way to perform drop sets with dumbbells is known as "running the rack," Adams said. To do it, you'll set up right next to dumbbells and perform one set of your chosen exercise at your chosen weight, then immediately pick up a lighter set of dumbbells and do it again, repeating until you've reached the lowest weight.

Note that if you're doing this in a commercial gym, be courteous and perform your sets close to the rack and put each set of dumbbells right back on the rack when you're done so others can use them.

You can also easily do drop sets on gym machines, which make it convenient to change the weight as needed.

If you don't have weights, resistance bands can also be used to create a similar drop set stimulus by switching from heavier to lighter bands as you progress.

Finally, barbells are ideal for drop sets using the "strip the bar" method of performing your reps, then pulling weight plates off either side and repeating.

The major caveat, however, is that you should avoid doing large drop sets with high-skill exercises such as Olympic lifts, since too much fatigue can reduce the effectiveness and increase injury risk, according to Adams.

Regardless of which type of weight or exercises you choose, a good starting point is to aim for at least three drops in weight before you finish, lowering by about 20 percent of the weight each time, he said.

On their own or as a challenging finisher to a traditional working, adding drop sets to your workouts can be a valuable tool to get the most out of your gym sessions, Adams said.

"When working out by themselves, people forget that these are techniques that they can use or they don't push themselves as hard when they're not with a trainer," he said.

You might need more recovery time from strenuous drop sets

The tradeoff with drop sets is if you're doing more than one per workout, all that extra work for your muscles can mean a longer rest before you're able to hit the gym again, according to Adams.

"If you're doing drop sets at the end of each movement, you'll have a much longer recovery curve because you've put additional stress on the muscle," he said.

Recovery is a key aspect of muscle growth, since you can't build back stronger if you're overtraining and not giving your body enough rest.