New training frequency study: 5x beats 2x

With the popularity of high frequency training, a ton of new research has been done on the best training frequency for muscle growth and strength development. Several of these studies have found no significant difference between lower and higher frequencies under volume-equated conditions (reviewed on this site or my Facebook page). But outside the lab we’re never in ‘volume-equated conditions’. We have a certain amount of time we want/can spend in the gym, often a certain amount of volume we tolerate and the practical question is: how do we distribute this number of sets across the week?

Everyone but the most bro of bros agrees by now that most people should train a muscle at least twice a week for maximum growth. The debate currently mostly centers on if training frequencies of 3+ per week are beneficial. A new study by Zaroni et al. (2018) involving my esteemed friend Brad Schoenfeld investigated exactly this in their paper titled: High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men.

18 Decently strength trained men – their average bench press exceeded 4 plates (over 100 kg) – were randomized to a program that trained each muscle either 5 times with 5 full-body workouts or once or twice with a bodybuilding split. The authors said that the split program trained each muscle group once a week, but look at the programs below. In red I commented on what was trained. The authors neglected that pull day trained the biceps and push day trained the triceps. So for the arms the comparison was a training frequency of 2x vs. 5x.

As you can see, the amount of sets per week, the exercises and the average intensity (RM) were exactly the same between groups. Both groups performed all exercises to failure (supposedly: I’m always extremely skeptical of this claim by researchers. Split squats and deadlifts to failure? I don’t think so.) Macronutrient intakes were also the same in both groups.