While a warm-up is nearly always recommended at the start of your workout, the recommendations on how to actually warm-up for hypertrophy training vary widely. This could be important, since performing better can boost volume load during the workout, which might play a role in stimulating muscle growth. Additionally, trimming the fat from your warm-up can save you time, freeing up more time for stimulative training (or – God forbid! – other hobbies).
Fortunately, when it comes to performance, we’re beginning to have some literature comparing the effectiveness of different warm-up strategies.
In a hot-off-the-presses study, a group of scientists in Brazil compared three different warm-up protocols in a cross-over design – each recreationally trained participant performed each test, and performance was compared across each trial.
The 40% warm-up condition had participants perform 15 repetitions with 40% of their 10-rep max. The 60% warm-up condition had participants perform 10 repetitions with 60% of their 10-rep max. Finally, the 80% warm-up condition had participants perform 5 repetitions with 80% of their working 10-rep max.
Following each warm-up protocol, 2 minutes of rest were taken before starting 3 sets of as many reps as possible with their 10-rep-max. Participants took 2 minutes of rest between each set. The exercises tested were the bench press, incline leg press, and wide grip lat pulldown.
The researchers measured a variety of performance-related variables. They measured reps performed on each set, as well as total training volume – essentially how many reps participants were able to complete across the three sets with their 10-rep-max. Finally, they also measured fatigue index, which is a proxy for fatigue, measuring the drop in repetitions achieved between the first and third set.
The results were straightforward: the greatest total training volume across the three exercises was achieved with the warm-up consisting of 80% of 10-rep max for 5 reps. Fatigue index was similar between groups.
If you’ve been following along with the research around warming up for hypertrophy training, this shouldn’t come as too big of a surprise.
Another recent study by Ribeiro et al found that a set of 8 repetitions with ~64% of 1-rep max enhanced performance compared to a set of 8 with only ~32% of 1-rep max during 3 sets of 6 at 80% of 1-rep max. Interestingly, even better performance was seen when combining a set of 8 at 32% 1RM with a set of 8 at 64%1RM.
Likewise, another 2024 study by Sousa et al found that a second, higher-load warm-up set with 90% 1RM, enhanced performance to a greater extent than performing a second warm-up set with 45% 1RM instead during 3 sets of squats to failure with 75% 1RM.
The beneficial effect of a heavy warm-up set for subsequent performance has been coined the “post-activation performance enhancement” (PAPE) effect in the research, and seems to be related to peripheral mechanisms like increased muscle temperature, water content, and enhanced muscle activation (1, 2).
For hypertrophy training, it looks like a heavy warm-up set beats a lighter warm-up set to enhance performance. There might be some additional benefit of doing one lighter set (around 20-50% 1RM), followed by the heavier warm-up set (around 50-85%1RM), but the heavier warm-up set appears to be the most important part. So, if you’re in a rush, stick to 1-2 sets, prioritizing the heavier warm-ups, especially if you already feel warm.
