Do you ever find yourself trying a little harder when you know someone is watching you lift? Maybe it's the really jacked person training next to you. Maybe it's your gym crush. Suddenly, your technique tightens up, your effort increases, and you squeeze out an extra rep or two that you normally wouldn't have gotten.
If you've ever taken a psychology class, this probably isn't too surprising. You may have heard of the Hawthorne effect, which refers to the tendency for people to change their behavior, often improving their performance, simply because they know they're being observed.
So what happens if you're always training with someone watching, such as a coach or training partner? Would you actually enhance your performance and make better gains?
Interestingly, this question has been examined in the research. A 2022 meta-analysis by Fisher et al. pooled data from 12 randomized controlled trials comparing supervised and unsupervised resistance training. The authors found that supervision led to greater strength gains, although its effects on body composition outcomes (fat-free mass, fat mass, and body fat percentage) were relatively modest.
In addition to these findings, Coleman et al. (2023) had trained men and women complete the same full-body resistance training program for 8 weeks. The only difference was that one group trained under the supervision of research assistants, while the other trained alone. The program included the lat pulldown, machine chest press, machine shoulder press, biceps curl, triceps pushdown, leg press, leg extension, and lying leg curl.
On average, the supervised group experienced greater increases in triceps brachii and vastus lateralis muscle size, along with greater improvements in Smith machine squat strength. However, both groups experienced similar gains in Smith machine bench press strength.
Why might this happen?
One possibility is that supervision improves both exercise technique and effort. For instance, when someone is watching and encouraging you, you may be more willing to push through discomfort and get closer to true muscular failure. It's also possible that supervision helps lifters maintain better exercise execution throughout a set, with these benefits potentially being more pronounced during complex movements (e.g., lower-body compound lifts).
Personally, I suspect that effort may have played a larger role than technique in this particular study. Most of the exercises were machine-based, so there was less room for technical differences to influence the results. We also know that training close to failure is an important driver of muscle growth, so it's possible that having someone there to supervise and encourage participants helped them consistently push harder during their sets.
From a practical standpoint, this doesn't mean everyone needs an in-person coach or personal trainer to build muscle. Plenty of people make excellent progress training on their own and more research is certainly needed to better understand how supervision influences muscle growth across different exercises and training populations.
That said, if your goal is to maximize muscle growth and you struggle to consistently push yourself hard during training, some form of supervision may be worth considering.
One obvious option is training with a partner who can provide encouragement and accountability during challenging sets. If you prefer training alone, recording your sets can be an underrated alternative. Simply knowing that a camera is recording can sometimes motivate you to push a little harder, even if nobody else ever watches the footage. Reviewing your videos can also help ensure your technique is matching your intentions.
You don't need to record every set of every exercise, especially if you're like me and find filming awkward in a crowded gym. But occasionally recording a hard set can help keep you honest and provide valuable feedback on both effort and technique.
Give it a try. You might be surprised by how much harder you train when you know someone, or something, is watching.
References:
1. Fisher, J., Steele, J., Androulakis-Korakakis, P., Smith, D., & Gentil, P. (2022). Evidence-Based Resistance Training Recommendations for Muscular Hypertrophy. International Journal of Strength and Conditioning, 2(1).
2. Coleman, M., Burke, R., Heilbronn, L. K., & Schoenfeld, B. J. (2023). Effects of supervision on resistance training adaptations in trained men and women. Journal of Sports Sciences, 42(3).