Energy Metabolism during Repeated Sets of Leg Press Exercise Leading to Failure or Not

Abstract

This investigation examined the influence of the number of repetitions per set on power output and muscle metabolism during leg press exercise. Six trained men (age 34±6 yr) randomly performed either 5 sets of 10 repetitions (10REP), or 10 sets of 5 repetitions (5REP) of bilateral leg press exercise, with the same initial load and rest intervals between sets. Muscle biopsies (vastus lateralis) were taken before the first set, and after the first and the final sets. Compared with 5REP, 10REP resulted in a markedly greater decrease (P<0.05) of the power output, muscle PCr and ATP content, and markedly higher (P<0.05) levels of muscle lactate and IMP. Significant correlations (P<0.01) were observed between changes in muscle PCr and muscle lactate (R2 = 0.46), between changes in muscle PCr and IMP (R2 = 0.44) as well as between changes in power output and changes in muscle ATP (R2 = 0.59) and lactate (R2 = 0.64) levels. Reducing the number of repetitions per set by 50% causes a lower disruption to the energy balance in the muscle. The correlations suggest that the changes in PCr and muscle lactate mainly occur simultaneously during exercise, whereas IMP only accumulates when PCr levels are low. The decrease in ATP stores may contribute to fatigue.

Blood Ammonia and Lactate as Markers of Muscle Metabolites During Leg Press Exercise

“…The present study was part of a larger project that examined the metabolic, neuromuscular response (9,10), and training effect (15) of the leg press exercise and was approved by the Institutional Review Committee of Instituto Navarro del Deporte (Government of Navarre, Spain), according to the Declaration of Helsinki. Muscle ATP and muscle lactate data of the 6 subjects that underwent biopsies have been reported in a previous study (9). The power output and blood ammonia and lactate values of the whole sample of 13 subjects are novel data.…”

“…This knowledge enables us to optimize the manipulation of acute resistance exercise variables to improve the design of resistance training programs aiming at enhancing neuromuscular performance. For instance, we have recently found that 5 sets of 10 repetitions to failure (5310RF) of bilateral leg press exercise interspersed by 2-minute resting pauses demanded a maximal effort and caused a disruption of cellular homeostasis, as reflected by a marked decrease in power output, a state of energy deficiency, and a decline in skeletal muscle phosphate potential (9). This resulted in a near-complete depletion of phosphocreatine (PCr) stores, a significant reduction in adenosine triphosphate (ATP) (21%) and muscle total adenine nucleotide pool as well as extremely high increases in inosine monophosphate (IMP) and muscle lactate that were accompanied by a wasteful loss of purines from muscle (9).…”

“…For instance, we have recently found that 5 sets of 10 repetitions to failure (5310RF) of bilateral leg press exercise interspersed by 2-minute resting pauses demanded a maximal effort and caused a disruption of cellular homeostasis, as reflected by a marked decrease in power output, a state of energy deficiency, and a decline in skeletal muscle phosphate potential (9). This resulted in a near-complete depletion of phosphocreatine (PCr) stores, a significant reduction in adenosine triphosphate (ATP) (21%) and muscle total adenine nucleotide pool as well as extremely high increases in inosine monophosphate (IMP) and muscle lactate that were accompanied by a wasteful loss of purines from muscle (9). However, when the number of repetitions in each set was reduced by 50%, a much lower decrease in muscle PCr content (;15 vs. 80% decline) was observed, with only modest increases in muscle lactate and no measurable changes in muscle levels of ATP and IMP, blood levels of uric acid, and whole-body purine stores.…”

Acute response to cluster sets in trained and untrained men

“…CLU incorporate a short rest (typically 15-30 s) between individual repetitions (inter-repetition rest) or group of repetitions (intra-set rest) (Haff et al 2008). The ability to maintain greater mechanical power output is facilitated by the ability of the phosphagen and glycolytic energy systems to recover during the added rest periods as evidenced by studies demonstrating lower blood lactate concentrations (Girman et al 2014;Goto et al 2005) following CLU when compared to TRD configurations, as well as greater intramuscular adenosine triphosphate (ATP) and phosphocreatine (PCr) concentrations (Gorostiago 2012).…”

Effects of Exercise Modality During Additional “High-Intensity Interval Training” on Aerobic Fitness and Strength in Powerlifting and Strongman Athletes

“…The hypothesis was partly support as both the AM and SM groups improved significantly in aerobic fitness and strength, however, changes in aerobic fitness where significantly greater for the AM group. These results further support the idea that Copyright ª 2017 National Strength and Conditioning Association appears to be the first study to directly compare aerobic and resistance training modes for both aerobic fitness and strength changes whilst attempting to match for effort and volume.Copyright ª 2017 National Strength and Conditioning Association greater drop in ATP:AMP ratio in addition to metabolite production when compared with lower effort exercise(30). AMPK is active independent of modality as long as effort is high due to its role as a key sensor of cellular energy requirements (i.e.…”