Check Out What I’ve Been Checking Out
What I’m Reading
“Hypertrophic Effects of Single- Versus Multi-Joint Exercise of the Limb Muscles: A Systematic Review and Meta-analysis”
If time-efficiency is important to you in the gym, you may wonder whether or not compound movements sufficiently train the secondary muscle groups involved. For example, you may wonder whether or not bench pressing is enough to stimulate muscle growth in your triceps.
If the answer is no, then you’ll want to complete tricep exercises in addition to completing pressing movements; however, if the answer is yes, then you can save a significant amount of time by taking care of your chest, front deltoid, and tricep training all with bench pressing alone.
Rosa and Colleagus’ explored this concept in their 2023 meta-analysis linked above and found the following:
“Research indicates that both [single-joint (SJ)] and [multi-joint (MJ)] exercises may produce similar muscle hypertrophy of the extremities. These findings suggest that practitioners seeking to increase muscle mass can employ MJ without the need to include SJ movements and thus achieve a more time-efficient workout.” (I)
Notably, their findings are specific to the arms and legs with most of the studies included in the meta-anlysis assessing muscle growth of the biceps brachii and triceps brachii. (I) In addition, their results come with a couple of caveats:
Some muscle groups–like the hamstrings, calves, and side deltoids–are not stimulated significantly in most multi-joint movements. (I) As a consequence, significantly growing these muscles likely requires incorporating isolation exercises. (I)
For bi-articular muscles with components that cross several joints–for example, the long head of the triceps brachii crosses both the elbow and the shoulder joints–multi-joint movements may not sufficiently stimulate all muscle heads. (I) As a result, you may require single-joint movements to achieve whole-muscle hypertrophy. (I) For example, since it does not involve movement in the overhead position, the bench press likely does not sufficiently stimulate the long head of the triceps brachii. (I) So, in order to achieve whole-muscle hypertrophy of the triceps, you may need to incorporate an overhead isolation movement, like the overhead triceps extension. (I)
“However, although it appears clear that MJ exercise can elicit appreciable increases in muscle mass of the upper and lower limbs, limitations of the current literature preclude the ability to draw strong inferences on the nuances of the topic. In particular, evidence suggests that the inclusion of SJ exercise can help to target specific subdivisions of a muscle, thus promoting more complete muscular development. Moreover, the paucity of research on adaptations between conditions in muscles, such as the hamstrings, calves, and others, does not allow for insights into potential effects of SJ exercises in these regions; preliminary evidence suggests a potential benefit.” (I)
With those caveats taken into account, in my opinion, this data does suggest that you can probably save time by counting multi-joint pressing and pulling movements–like the bench press and the pull-up–towards weekly volume for your biceps and triceps–especially if you are less concerned with achieving optimal or maximal results.
And, even if you do choose to add in some isolation exercises for your biceps and triceps, like the overhead tricep extension I mentioned above, I think you can still save time considering that you can probably cut out some of your previous isolation volume by limiting the extra sets to these bi-articular movements specifically.