Do the Acute Biochemical and Neuromuscular Responses Justify the Classification of Strength- and Hypertrophy-Type Resistance Exercise?

Abstract

The present study aimed to examine a wide profile of acute biochemical and neuromuscular responses to strength (STR) and hypertrophy (HYP) resistance exercise (RE). Seven trained males completed a STR workout (4 x 6 repetitions, 85% one repetition maximum [1RM], 5 min rest periods), a HYP workout (4 x 10 repetitions, 70% 1RM, 90s rest periods) and a control condition (CON) in a randomised cross-over design. Peak force (PF), rate of force development (RFD) and muscle activity were quantified pre-and post-exercise during an isometric squat protocol. Blood samples were taken 20, 10 and 0 minutes pre-and 0, 10 and 60 minutes post-exercise to measure the concentration of blood lactate (BL), pH and a number of electrolytes that were corrected for plasma volume changes.No differences were observed between the workouts for changes in PF, RFD or muscle activity.Repeated contrasts revealed a greater (p ≤0.05) increase in BL concentration and reduction in pH following the HYP protocol than the STR or CON conditions. There were similar but significant (p ≤0.05) changes in the concentration of a number of electrolytes following both workouts and a handful of these changes displayed significant correlations with the PF reductions observed following the HYP condition. Although the STR and HYP workouts were significantly different in terms of intensity, volume and rest, these differences were only observable in the acid-base responses. The present findings reinforce the need for practioners to look beyond the classification of RE workouts when aiming to elicit specific physiological responses.

Acute neuromuscular and metabolic responses to upper body strength, power, and hypertrophy protocols in resistance trained men

“…For hypertrophy-type sessions (H) were studied using 3 to 5 sets, ~10 repetitions maximal or 70 to 80% 1RM, and rest intervals of 90 seconds to 3 minutes [1][2][3][4]24] . The reduction of ~24% on peak force after a H session is in accordance with previous studies (~16 to 48%) [5,6,22,23] . In addition, the S and H session presented high values for total volume load when compared to the P session.…”

“…Additionally, McCaulley et al, [6] investigated the acute neuromuscular and metabolic response to S, P, and H sessions with equated relative volume via S: 11 sets of 3 repetitions in the squat exercise at 90% of 1RM with 5-minutes rest; H: 4 sets of 10 repetitions at 75% of 1RM with 90-seconds rest; and P: 8 sets of 6 repetitions of jump squats using body weight with 3-minutes rest. Their BL results were similar to Nicholson et al, [5] , and H elicited the greatest increase followed by S, while P did not present any variation relative to baseline. They also observed a reduction in PF and RFD after S and H in the MVIC squat test.…”

“…The S session allows a high amount of load to be lifted, and, it also induces a drop in the peak force (~25%) [5,6,22,23] . Despite all differences in our procedures, it was observed 7 to 30% in the reduction of peck force that corroborates with previously studies [5,6,22,23] . On the other hand, the effects observed in force and total volume load of the present study cannot be only attributed to neural adjustments, as shown by IEMG and median frequency.…”

“…Despite the current RT scientific literature which has already classified protocols as strength (S), power (P), or hypertrophy (H) [1][2][3][4] , recent reports have questioned these divisions based on acute responses of the neuromuscular and metabolic systems [5,6] . Nicholson et al., [5] tested the acute biochemical and neuromuscular responses of S and H sessions via a S (4 x 6 repetitions at 85% of 1RM, with 5-minute rest), a H (4 x 10 repetitions at 70% of 1RM, with 90-second rest), and control.…”

“…Nicholson et al., [5] tested the acute biochemical and neuromuscular responses of S and H sessions via a S (4 x 6 repetitions at 85% of 1RM, with 5-minute rest), a H (4 x 10 repetitions at 70% of 1RM, with 90-second rest), and control. They observed an increase in blood lactate (BL) and a reduction in pH after the H compared to S, however, there were no differences between sessions for peak force (PF), rate of force development (RFD), or muscle activity during a maximal voluntary isometric contraction (MVIC) squat test.…”