The Line Between Hypertrophy and Strength Is More Grey Than Black
In the raging battle and constant confusion over what training protocols work better for strength and size, a recent Journal of Strength and Conditioning Research article asks a different question: Is our distinction between these two protocols even important?
Coaches often advise different programs to athletes with goals of either strength or muscle development. However, recent research has called this practice into question. With low-rep, high-intensity programs proving effective for size, and the weakening grip of the hormone paradigm as the stimulus for anabolism, the researchers in the Journal study wished to reexamine our definitions of various program designs.
The participants performed two different workouts in a random order. Their blood was tested, as well as their strength and rate of force development. The researchers compared the strength and hypertrophy protocols to identify the chemical or mechanical differences between the two.
The hypertrophy plan was the back squat, performed to parallel for four sets of ten reps with a minute and a half in between sets. The load was seventy percent of one-rep-max (1RM). The strength protocol was four sets of six at 85% of the subjects' 1RM. During the strength program, they got five minutes of rest between sets.
The differences in volume was intended to make the two programs more realistic. However, the researchers acknowledged that the strength program isn’t what some might call a pure strength program.
There was a big difference in the biochemical response between protocols. While both programs increased blood lactate and acidity, the hypertrophy program did so to a greater degree. As a result there were some differences in electrolyte status as well, most notably sodium. The sodium levels were nearly three times higher in the hypertrophy group, perhaps as a buffering mechanism for the acid.
However, in spite of the biochemical differences, the researchers highlighted the similarities in neuromuscular response. That is to say, the participants experienced a similar loss of strength and rate of force development as the sets went on. This is important because of the big difference in protocol. The two programs used different intensities, different volumes, and different rest periods. They also had the above mentioned differences in acidity and electrolytes. Despite all this, the fatigue levels were similar.
The researchers noted the small sample size might have made these results a little dodgy if it weren’t for the agreement found in other studies. It seems that neuromuscular fatigue response is the same across various programs, as long as intensity rises above a certain threshold.
In the end, the researchers concluded with a caution for using typical terminology to differentiate between hypertrophy training and strength training. Because of the similar fatigue response observed in the study, it can’t be said that our phrasing is wholly accurate. What we consider hypertrophy training will develop strength, and what we call strength training will develop lean muscle. The researchers recommended using a repetition continuum scale as a more appropriate visual discussion aid that might illustrate the blurred boundaries in physiological response.
In light of this evidence, it seems more appropriate to choose your workout based on factors other than one specific response you’re looking for. In other words, choose what you think is the most fun.
1. Gareth Nicholson, et. al., “Do the acute biochemical and neuromuscular responses justify the classification of strength and hypertrophy-type resistance exercise?,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000519
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