Neuromuscular Fatigue and Metabolic Stress during the 15 Minutes of Rest after Carrying Out a Bench Press Exercise Protocol

Abstract

Background: Velocity loss (VL) at 1 m·s−1 can help to determine neuromuscular fatigue after performing an exercise protocol. The aim of this study was to analyse muscle fatigue and metabolic stress during the 15 min that follow the execution of a bench press (BP) exercise protocol. Methods: Forty-four healthy male students of sports science performed two exercise sessions separated by one week of rest. In the first week, the participants carried out a test with progressive loads in the (BP) exercise until reaching the one-repetition maximum (1RM) in order to obtain the load–velocity relationship of each participant. In the second week, each participant conducted three BP exercise sets at an intensity of 70% of 1RM, determining this load through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship, with the participants performing the maximum number of repetitions (MNR) to muscle failure. Two minutes of rest were allocated between sets. MPV at 1 m·s−1 and blood lactate concentrations were recorded before executing the exercise and at minute 0, 5, 10 and 15 after performing the exercise protocol. Results: A two-factor repeated measures ANOVA was performed. MPV at 1 m·s−1 in minute 0 post-exercise was −33.3% (p < 0.05), whereas in minute 10 and 15 post-exercise, it was ≈−9% (p > 0.05). Regarding the blood lactate levels, significant differences were observed in all measurements before and after the exercise protocol (p < 0.001), obtaining ≈7 mmol·L−1 at minute 10 post-exercise and 4.3 mmol·L−1 after 15 min of recovery. Conclusions: MPV with medium or moderate loads shows a certain recovery from minute 10 of rest. However, the blood lactate levels are still high (>5 mmol·L−1). Therefore, although there seem to be certain conditions to reach a similar maximum MPV peak, the residual fatigue at the neuromuscular level and the non-recovery of metabolic homeostasis would hinder the reproduction of these protocols, both at the level of applied stimulus and from a methodological perspective, since a long recovery time would be required between sets and exercises.

Fatigue and Metabolic Responses during Repeated Sets of Bench Press Exercise to Exhaustion at Different Ranges of Motion

“…Blood lactate concentration after high intensity exercise of this volume is expected to reach a peak after 1.3 to 3.3 min from the cessation of exercise ( Chatel et al, 2016 ), but information on this is sparse. The level of blood lactate concentration reached after this protocol is in line with previous studies reporting comparable values after 3 sets to failure using a relative load corresponding to 70% of 1-RM ( Heredia-Elvar et al, 2022 ; Hernández-Lougedo et al, 2022 ). Despite the relatively small muscle mass, the considerable increase in blood lactate concentration within only three sets of the bench press exercise may indicate high metabolic stress and considerable glycolytic contribution ( de Freitas et al, 2017 ; Schoenfeld, 2013 ).…”

“…It has been reported that during fatiguing protocols to instant exhaustion (e.g., during hypertrophy protocols), blood lactate concentration increases significantly and remains elevated for around 15 min post exercise ( Heredia-Elvar et al, 2022 ; Hernández-Lougedo et al, 2022 ), while movement velocity of the barbell decreases linearly ( Tsoukos et al, 2021 ) and the number of completed repetitions also decreases during repeated sets of exercise ( Heredia-Elvar et al, 2022 ; Hernández-Lougedo et al, 2022 ). There is evidence showing that blood lactate responses during resistance exercise depend not only on the total work, but mainly on the frequency of repetitions.…”

Effects of Creatine Supplementation after 20 Minutes of Recovery in a Bench Press Exercise Protocol in Moderately Physically Trained Men

“…To the best of our knowledge, this is the first study in the literature that measured post-exercise fatigue through velocity loss in CR supplementation protocols, although recent studies have analysed this mechanical variable. The results of such studies are similar to those of the PLA group, measuring an MPV of 1 m·s −1 for up to 15 min after the exercise during the same exercise protocol [ 35 ]. Nevertheless, a different study with two types of functional fitness training (strength and endurance ones) involved participants performing squat and military press exercises, and recording an MPV of 1 m·s −1 15 min after the exercises, the researchers found higher velocity values in all of the control points, with them even regaining the pre-exercise velocity after 15 min of recovery [ 36 ].…”

“…After determining the individualised load at which a velocity of 1 m·s −1 was obtained, 3 repetitions of BP were performed before and at 0, 5, 10, 15, and 20 min after the exercise protocol. As per the study by Hernandez-Lougedo et al, [ 35 ] the participants performing the same bench pressing protocol almost reached pre-exercise MPV levels after 15 min of recovery, and so a post-exercise measurement at 20 min was included in this study. All of the repetitions were carried out at maximum velocity.…”

“…Nevertheless, although these earlier studies associate the improvements in performance with a greater capacity to recover between sets, a few studies have measured the recovery period after performing an intense exercise protocol. Recent studies have measured recovery at 15 min after a multiple-set exercise protocol with bench pressing [ 35 ] or a high-interval functional training protocol [ 36 ], with the aim of determining the recovery time required to perform another exercise protocol in the same session, reaching levels of execution velocity that are similar to those that were obtained in the first protocol, in order to reduce the residual fatigue and increase the performance capacity. In this sense, it would be interesting to know whether creatine supplementation can help people to recover the initial strength levels after performing an exercise protocol.…”