We like to be watched. Why else are so many of us Instagramming our every meal and workout? And research has shown that people generally perform better on simple tasks (and worse on complex ones) when being observed. This is called social facilitation, and it applies to weight-training. A new study looked to see just how deep this goes with a twist or two on the classic question: How much can you bench— for reps—with and without spotters?

A previous study, with 32 participants, showed that one-rep max bench presses improved by 13% when performed before an audience. A new study explicitly set out to replicate more common training conditions: a couple of partners or none at all. Twelve experienced weight-trainers performed three sets of bench presses at 60% of their one-rep max (ex: 180 for a 300-bencher), to failure, with two minutes rest between sets. On one day, they benched with a silent spotter on each side of the bar. On the other day, they were alone (the spotters were hidden). The subjects totalled 11.2% more reps with spotters than without. That’s the difference between nine reps and 10.

Spot me, bro. / credit: Olufemi Owolabi

Of course, with a spotter (or spotters) you’re able to truly go to failure (missing your last rep) and get help re-racking the weight. (The study did not note this happening.) But there was more to these bench sessions. After sets, participants ranked their perceived exertion (how hard they thought they’d worked) and self-efficacy (belief in ability at a given task, in this case: hitting again the rep total of their previous set). With spotters, their perceived exertion was 8% lower, even though they were cranking out more work, and their self-efficacy was 45% higher, even though they ultimately fared no better in hitting their previous targets.

In other words, they thought they were working a little less hard and they were a lot more self-confident when being watched. The researchers concluded: “This study demonstrates that resistance exercise is improved by the presence of spotters, which is facilitated by reduced ratings of perceived exertion and increased self-efficacy. This has important implications for athletes and clients, who should perform resistance exercise in the proximity of others, to maximize total work performed.” These “others” were silent strangers. It’s probable that an encouraging training partner would’ve helped the benchers eke out still more reps.

Get a spot, not just on the heavy max you’re afraid you might miss, but even on lighter sets. We perform better when we’re being watched.