Do Cheat Reps Help Build Muscle? A Look at the Latest Research

Key Takeaways on Cheat Reps:

• Cheat reps won’t kill your gains. A recent cheat reps study found that using a little momentum while lifting doesn’t hurt muscle growth compared to strict form.
• You can lift heavier with cheat reps. Using some body movement lets you push more weight, which might help break plateaus.
• Strict form still has its place. It’s great for muscle isolation and lowering injury risk, so don’t throw it out completely.

Do Cheat Reps Kill Your Gains?

For years, gym-goers have heard the same thing: Always use strict form. Full range of motion is the only way to maximize gains. But what if that’s not the whole story? A new cheat reps study by the research team at CUNY Lehman College put this theory to the test, focusing on biceps curls and triceps pushdowns. Their goal? To find out if using momentum in these exercises leads to less muscle growth than strict form. The researchers’ results suggest that cheat reps may not be as bad for muscle growth as once thought.¹

Why Full Range of Motion Was the Golden Rule

For decades, the belief was simple: the more control and range you have over a movement, the better the results. Trainers and fitness organizations, including the National Strength and Conditioning Association, have long preached that strict form and full range of motion lead to greater muscle activation and prevent injuries.²

It makes sense—if you’re swinging the weight up, aren’t you making the exercise easier? Many bodybuilders feared that by using momentum, they’d shift the effort away from their target muscle and compromise gains. However, some strength coaches have argued the opposite. They believe cheat reps allow lifters to handle more weight and increase total training volume, which is another key factor for muscle growth.

Cheat Reps: What the Research Says

The conversation around cheat reps has been going on for years. Some swear by them; others say they’re a recipe for disaster. So, what does the research actually tell us?

Pros of Cheat Reps

Let’s start with the benefits. Swinton et al. (2011) found that using a bit of momentum can increase torque, making it possible to lift heavier weights without adding more load to the muscle.³ That might sound like cheating in the worst way; cheat reps might activate high-threshold motor units that strict form doesn’t always hit. In other words, a little body swing could actually lead to more muscle activation.⁴ Research on resistance training suggests that some degree of “cheating” or momentum can help overcome sticking points, allowing for additional reps and increased time under tension, both of which contribute to hypertrophy.¹

Then there’s the question of whether training to failure is really necessary. Grgic et al. (2022) found that you don’t have to hit complete failure every set to build muscle.⁵ This means cheat reps could be a solid alternative to fully exhausting yourself every workout. Similarly, Vieira et al. (2021) showed that muscle growth was pretty much the same whether participants trained to failure or not.⁶ That suggests you can still push hard without burning out too fast—cheat reps might help you do just that.

Cons of Cheat Reps

But let’s not get carried away. Cheat reps aren’t all sunshine and gains. Baechle and Earle (2008) warn that if you’re not careful, swinging weights around could put unnecessary strain on your joints and tendons. Strict form keeps the focus locked onto the target muscle, while cheat reps tend to spread the effort across multiple muscles. That might sound useful, but if your goal is maximum muscle isolation, cheat reps could be counterproductive. If you’re using cheat reps without a plan, you might not see the same benefits as someone who knows exactly when and how to use them.

Putting Cheat Reps to the Test

The researchers decided to settle this debate with an eight-week study comparing cheat reps vs strict reps. They had 30 participants train one arm with strict form and the other using cheat reps. The exercises? Biceps curls and triceps pushdowns.

Strict reps: Full range of motion, controlled movement, no extra momentum.

Cheat reps: Some momentum allowed, making it easier to move heavier weights.

Each participant trained twice a week, doing four sets of 8–12 reps. The researchers measured muscle thickness with ultrasound and checked for changes in arm circumference. The results? Not what most people expected.

What the Study Found

After eight weeks, both groups had similar increases in muscle size. Yep, cheat reps didn’t hold anyone back. Bayesian analysis supported the idea that neither training style had a clear advantage over the other.

Key Takeaways:

• Muscle Thickness: Both training styles led to similar gains.
• Arm Size: No significant differences in circumference between the two groups.
• Training Volume: Cheat reps let participants lift heavier, but that didn’t translate to extra growth.

So, if you’ve been avoiding cheat reps because you thought they’d ruin your progress, this cheat reps vs strict reps study suggests otherwise. But before you start swinging weights around wildly, there’s more to consider.

Final Thoughts on Cheat Reps

For years, we were told that strict form was the only way to build muscle. But as research evolves, we’re seeing that when comparing cheat reps vs strict reps, lifting isn’t always that black and white. Cheat reps aren’t a shortcut to avoiding hard work, but they also won’t kill your gains.

So, should you cheat? The answer is: it depends on your goals. If you use them strategically, cheat reps can be a great tool to add variety, break plateaus, and push heavier weights. Just don’t abandon strict form completely—there’s still plenty of value in controlled, full-range movements.

At the end of the day, smart training is about knowing when to push limits and when to dial it back. Now, go lift something heavy—and if you need to cheat a little, we won’t tell.

References

1               Augustin, F. et al. Do cheaters prosper? Effect of externally supplied momentum during resistance training on measures of upper body muscle hypertrophy. (2024).

2               Earle, R. Essentials of Strength Training and Conditioning, 3E. (2008).

3               Swinton, P. & Murphy, A. Comparative effect size distributions in strength and conditioning and implications for future research: A meta-analysis. (2022).

4               Swinton, P. A., Stewart, A., Agouris, I., Keogh, J. W. & Lloyd, R. A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads. J Strength Cond Res 25, 2000-2009 (2011). https://doi.org/10.1519/JSC.0b013e3181e73f87

5               Grgic, J., Schoenfeld, B. J., Orazem, J. & Sabol, F. Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis. J Sport Health Sci 11, 202-211 (2022). https://doi.org/10.1016/j.jshs.2021.01.007

6               Vieira, A. F. et al. Effects of Resistance Training Performed to Failure or Not to Failure on Muscle Strength, Hypertrophy, and Power Output: A Systematic Review With Meta-Analysis. J Strength Cond Res 35, 1165-1175 (2021). https://doi.org/10.1519/jsc.0000000000003936