Some athletes swear by total-body routines that allow you to train a muscle as frequently as possible whereas others support a traditional body part split where you train a muscle once per week. A recent study probed the effect of training frequency of these two different splits on muscular adaptations in a controlled experiment.
Brad Schoenfeld and his team took 19 trained men with an average lifting career of 4 years and assigned them to follow the two opposing training splits (10 in the total-body group and 9 in the body part split group).Both groups performed an equal number of sets and reps over the course of 8 weeks in a controlled setting.
One group followed a total-body (all muscles worked in a session) and the other used a split-body routine (2-3 muscle groups worked in a session).
The study concluded that total-body workouts performed three times per week produced significantly greater increases in forearm flex muscle (biceps and brachialis) thickness than the body part split routine. Schoenfeld and colleagues found the reason for the increase in muscle gain was simply because the muscles were worked more often.
“…athletes need to use both splits in their yearly periodized plan to continue making progress.”
Increased frequency packs on more muscle since muscle protein synthesis is elevated for about 48 hours after training. If a muscle is worked every Monday, Wednesday and Friday it should undergo some amount of protein synthesis for the entire week. If the two programs were matched by volume (sets x reps x weight) then a total- body routine results in more muscle gain.
Both groups also increased their strength in the bench press and squat although the effect size for the bench press did seem to favour the total-body subjects. All the muscles showed greater growth from a higher training frequency although a benefit of the split routine was the ability to increase per-workout volume while affording sufficient recovery. Muscular adaptations enhance when program variables change outside the traditional norms.This might have been the main reason subjects in the total-body group benefited from the unaccustomed stimulus of training more frequently because they were following a traditional body part split before the study. The result of this research may not be that total-body workouts are better than body part split workouts but that athletes need to use both splits in their yearly periodized plan to continue making progress.