I’ve been a big proponent of using long rest intervals for hypertrophy for some time now, and research continues to support this practice. Another common question many athletes and coaches pose is how cardio affects size and strength gains. An interesting new study in the Journal of Strength and Conditioning Research addressed both of these topics.
There were seventeen participants divided into two groups. Both of the groups performed the bench press and squat, with each group doing a different one of these two first. Within the two groups, three different protocols were performed, for a total of six conditions:
- Bench press then squat with one-minute rest
- Bench press then squat with two-minute rest
- Bench press then squat with three-minute rest
- Squat then bench press with one-minute rest
- Squat then bench press with two-minute rest
- Squat then bench press with three-minute rest
The researchers used a fairly standard bodybuilding load of 75% for both lifts, and the lifts were performed for five sets of up to ten repetitions each. In addition to measuring performance, the researchers calculated the VO2 consumption (and thus, energy use) of each participant as they exercised. To determine the effects of oxygen consumption on resistance exercise performance, the participants had widely different VO2 max levels at the start. These values were also compared to multiple performance variables.
The bench-press-first group performed more total repetitions, although the researchers noted the difference was not statistically significant. This is interesting information since in the real world, this sort of protocol might be performed with squats first. However, the bench press being first only worsened squat performance by an average of one rep across five sets when using three-minute rests. To contrast, doing the squat first made the bench go down by an average of 6.5 reps over five sets.
Many lifters also follow the old hypertrophy paradigm of short rest intervals to maximize hormonal response, but the results suggest this practice may not be warranted. Quite the opposite, actually. For the squat-first group, one-minute rests reduced the total number of reps for the workout by 16.5 on average, and 18.5 reps for the bench-first group when compared to three-minute rests.
Not surprisingly, V02 max was negatively correlated with strength. This means that the better a participant’s V02 max, the weaker they were. Since VO2 max is also negatively correlated to body size, this is pretty uncontroversial. Interestingly though, the number of squat reps the participants could perform with short rest intervals was higher in the subjects with a better VO2 max. Essentially, better cardio meant more volume and thus more size to a certain point. However, more size also meant worse cardio in some cases, so it seems there’s some kind of limit.
With this set up, a bench-first method with long rest intervals might work best for hypertrophy, since both conditions allow for greater total volume. If you must use short rest periods due to a time crunch, having good cardio seems to be beneficial. With longer rest periods it seems you can skip the cardio if your priority is getting big.
1. Nicholas Ratamess, et. al., “Acute Oxygen Uptake and Resistance Exercise Performance Using Different Rest Interval Lengths: The Influence of Maximal Aerobic Capacity and Exercise Sequence,” Journal of Strength and Conditioning Research, 28(7), 2014
Photo courtesy of CrossFit Impulse.