How to Strength Train Faster, According to Science

If you struggle to find enough time to exercise, you're not alone. Even though an effective workout can be long, short, or anywhere in between, we often let the time commitment exercise requires become a barrier, and figure it's not worth even starting. Fortunately, a review paper by sports scientists has gathered a set of guidelines for time-efficient strength workouts, and their recommendations will help you get the most work done in the shortest amount of time.

How much time is enough for a strength workout?

Anything is better than nothing, so in that sense no workout is too short. The authors of this study point out that even 15-minute workouts are probably effective, as long as you get enough sets in across your week.

So think of your workouts in terms of a full week, and count up how many sets you do. Four to 12 sets per muscle group, per week seem to be enough for a basic level of strength gains. (Speaking very generally, two to three sessions of 20 to 30 minutes each are often enough to accomplish that.)

So how do you get enough quality work in during those short sessions? Here are the science-backed recommendations.

Skip the stretching and shorten your warmup

When you first get to the gym, do you spend 20 minutes doing cardio, stretching, and moving your body through a series of warmup exercises? If so, you can save a lot of time by cutting out everything that doesn't have a specific reason for being a part of your routine. (By coincidence, that's exactly what I would recommend anyway.)

The ideal time-crunched warmup, the authors of the review write, is one that gets right to the point: [W]e advise restricting the warm-up to exercise-specific warm-ups, and only prioritize stretching if the goal of training is to increase flexibility."

So skip the stretches, unless you need them to get ready for the specific exercise you're about to do, and proceed to your "exercise-specific warmups," which means doing lighter sets of the exercise you're about to do. For example, if you plan to do barbell squats, you would warm up by squatting the empty bar and then squatting some light weights before loading the bar for your first working set.

If that doesn't sound like enough to you, remember that these are just guidelines, and you're free to include anything that you enjoy doing or that makes your workout feel better. For more on how to tweak your warmup to your needs, take a look at our guide to warming up, where we explain the purpose of each part of the warmup. But just because you can include something in a warmup doesn't mean you have to.

Choose multi-joint, bilateral exercises

The exercises that work the most muscles in the shortest time are ones that are bilateral (using both arms or both legs at the same time) and that see you bending multiple joints rather than just one. Ideally, they should also involve both a lifting and a lowering movement.

For example, a bicep curl done with one dumbbell is unilateral (one arm) and single-joint (you're just asking your bicep to flex your elbow). A pull-up, on the other hand, uses both arms, and it involves your elbows and your shoulders. If you've ever done pull-ups, you'll know that they work just about everything from the waist up. That makes them perfect for a time-crunched workout.

The authors write that if you can only choose three exercises, make them:

• An upper body pull (like a pull-up or row)

• An upper body push (like a bench press, pushup, or overhead press)

• A leg exercise (like a squat)

Machines and free weights both work, they write, so you could use the leg press instead of doing a barbell squat, or use a chest press machine instead of a bench press station. They prefer barbells over dumbbells if you have the option, since you can usually move more weight in a barbell lift than in its dumbbell equivalent. Resistance bands and bodyweight moves can work too, as long as they are challenging enough to hit the appropriate number of reps.

Lift heavy enough that you can do 6-15 reps

How many reps should you do in each set? That's a long-debated question, to which the authors of this paper have two answers.

The ideal scenario is where you're at a gym and can choose any weights you like. Do sets that are heavy enough that the last few reps feel challenging. These sets can be anywhere between six and 15 reps, and the last one doesn't have to be to total failure; you can stop when it feels like you would only be able to squeeze out a few more. (Notice how your movement slows down on those last few reps. That's a sign that you're getting close.)

The other option, if you don't have heavy enough weights, is to do exercises to complete failure-the point where you simply cannot complete another rep. In this case, reps can be anywhere from 15 up to 40.

Don't rest long between sets

Normally you'd rest between two and five minutes between sets, depending on the exercise. But to save even more time, you can simply rest less between sets. If you're new to lifting, one to two minutes is probably fine, the authors write. (You may not be able to load as much weight on the bar as you could with longer rests, but your muscles are still getting plenty of work.) To condense things further, you can add a few time-honored bodybuilder hacks: supersets, drop sets, and rest-pause sets all give your muscles more work in less time.

How often should I strength train?

Two or three times per week is great when you're doing full-body workouts. But the authors note that what matters is the total amount of exercise you get done, not the number of days you exercise. So if you can only manage one session each week, but you're able to spend a little more time on it, you can effectively cram a whole week's worth of strength training into one day.

On the flip side, if you can only manage 15 minutes a day, but you can do that every day, you may still be able to get in the same amount of work as somebody who does two or three normal sessions a week.

What counts as a week's training? The authors recommend four to 12 sets per muscle group, per week. Four is on the low end compared to what many gym-goers do, but we're trying to find the minimum that will keep you in shape-so if you can only manage four, four it is. They note that research has found that people who are new to strength training can manage to build muscle with very little exercise (three sets per week, in some studies), so even a small amount of strength training is worth your time.

Going back to our three-exercise framework, if you can do four sets of push, four sets of pull, and four sets of legs, that's your weekly minimum right there. Do that in one day if that's all you can manage, or spread it over the course of the week. More is better, but that's your minimum target.