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Chae S, Long SA, Lis RP, McDowell KW, Wagle JP, Carroll KM, Mizuguchi S, Stone MH. Combined Accentuated Eccentric Loading and Rest Redistribution in High-Volume Back Squat: Acute Stimulus and Fatigue. J Strength Cond Res 2024; 38:648-655. [PMID: 38241478 DOI: 10.1519/jsc.0000000000004694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
ABSTRACT Chae, S, Long, SA, Lis, RP, McDowell, KW, Wagle, JP, Carroll, KM, Mizuguchi, S, and Stone, MH. Combined accentuated eccentric loading and rest redistribution in high-volume back squat: Acute stimulus and fatigue. J Strength Cond Res 38(4): 648-655, 2024-The purpose of this study was to examine acute stimulus and fatigue responses to combined accentuated eccentric loading and rest redistribution (AEL + RR). Resistance-trained men ( n = 12, 25.6 ± 4.4 years, 1.77 ± 0.06 m, and 81.7 ± 11.4 kg) completed a back squat (BS) 1 repetition maximum (1RM) and weight releaser familiarization session. Three BS exercise conditions (sets × repetitions × eccentric-concentric loading) consisted of (a) 3 × (5 × 2) × 110/60% (AEL + RR 5), (b) 3 × (2 × 5) × 110/60% (AEL + RR 2), and (c) 3 × 10 × 60/60% 1RM (traditional sets [TS]). Weight releasers (50% 1RM) were attached to every first repetition of each cluster set (every first, third, fifth, seventh, and ninth repetition in AEL + RR 5 and every first and sixth repetition in AEL + RR 2). The AEL + RR 5 resulted in greater total volume load (sets × repetitions × eccentric + concentric loading) (6,630 ± 1,210 kg) when compared with AEL + RR 2 (5,944 ± 1,085 kg) and TS (5,487 ± 1,002 kg). In addition, AEL + RR 5 led to significantly ( p < 0.05) greater rating of perceived exertion (RPE) after set 2 and set 3 and lower blood lactate (BL) after set 3 and 5, 15, and 25 minutes postexercise than AEL + RR 2 and TS. There was a main effect of condition for BL between AEL + RR 5 (5.11 ± 2.90 mmol·L -1 ), AEL + RR 2 (6.23 ± 3.22 mmol·L -1 ), and TS (6.15 ± 3.17 mmol·L -1 ). In summary, AEL + RR 5 results in unique stimulus and fatigue responses. Although it may increase perceived exertion, coaches could use AEL + RR 5 to achieve greater back squat total volume load while reducing BL accumulation.
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Affiliation(s)
- Sungwon Chae
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
- Department of Kinesiology, Coastal Carolina University, Conway, South Carolina
| | - S Alexander Long
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
| | - Ryan P Lis
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
| | - Kurt W McDowell
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
| | - John P Wagle
- University of Notre Dame, Athletics, Sports Performance, Notre Dame, Indiana
| | - Kevin M Carroll
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
| | - Satoshi Mizuguchi
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
| | - Michael H Stone
- Department of Sport, Exercise, Recreation, and Kinesiology, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee
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Chae S, Hill DW, Bailey CA, Moses SA, McMullen SM, Vingren JL. Acute Physiological and Perceptual Responses to Rest Redistribution With Heavier Loads in Resistance-Trained Men. J Strength Cond Res 2022; 37:994-1000. [PMID: 36227234 DOI: 10.1519/jsc.0000000000004366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
ABSTRACT Chae, S, Hill, DW, Bailey, CA, Moses, SA, McMullen, SM, and Vingren, JL. Acute physiological and perceptual responses to rest redistribution with heavier loads in resistance-trained men. J Strength Cond Res XX(X): 000-000, 2022-The purpose of this study was to explore the effect of rest redistribution with heavier loads (RR + L) on physiological and perceptual responses in resistance-trained men. Eight men who had back squat (BS) 1 repetition maximum (1RM) to body mass ratio; 1.8 ± 0.2 completed 2 BS exercise sessions in a counterbalanced and a randomized order; RR + L: 4 sets of (2 × 5) repetitions with 90-second interset rest and 30-second intraset rest using 75% BS 1RM and traditional sets (TS): 4 sets of 10 repetitions with 120-second interset rest using 70% BS 1RM. Blood samples were collected before exercise, immediately post exercise, and 5, 15, and 30 minutes post exercise for the analysis of growth hormone (GH), total testosterone (TT), cortisol (C), and blood lactate (BL), whereas rating of perceived exertion (RPE) and heart rate (HR) were measured immediately after each set of the BS exercise. While neither main effect of condition nor interaction existed, there was a significant (p < 0.05) main effect of time point (and set) for GH, TT, C, BL, RPE, and HR. Volume load was greater for RR + L compared with TS (4,074.9 ± 786.7 kg vs. 3,796.3 ± 714.8 kg). In conclusion, RR + L increases volume load by approximately 7% but does not seem to influence GH (g = -0.15), TT (g = -0.09), BL (g = -0.22), RPE (g = 0.14), and HR (g = -0.08) responses. Practitioners may consider using RR + L to increase volume load without increasing acute fatigue responses.
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Affiliation(s)
- Sungwon Chae
- Applied Physiology Laboratory, Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, Texas
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Refalo MC, Helms ER, Hamilton DL, Fyfe JJ. Towards an improved understanding of proximity-to-failure in resistance training and its influence on skeletal muscle hypertrophy, neuromuscular fatigue, muscle damage, and perceived discomfort: A scoping review. J Sports Sci 2022; 40:1369-1391. [PMID: 35658845 DOI: 10.1080/02640414.2022.2080165] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
While proximity-to-failure is considered an important resistance training (RT) prescription variable, its influence on physiological adaptations and short-term responses to RT is uncertain. Given the ambiguity in the literature, a scoping review was undertaken to summarise evidence for the influence of proximity-to-failure on muscle hypertrophy, neuromuscular fatigue, muscle damage and perceived discomfort. Literature searching was performed according to PRISMA-ScR guidelines and identified three themes of studies comparing either: i) RT performed to momentary muscular failure versus non-failure, ii) RT performed to set failure (defined as anything other than momentary muscular failure) versus non-failure, and iii) RT performed to different velocity loss thresholds. The findings highlight that no consensus definition for "failure" exists in the literature, and the proximity-to-failure achieved in "non-failure" conditions is often ambiguous and variable across studies. This poses challenges when deriving practical recommendations for manipulating proximity-to-failure in RT to achieve desired outcomes. Based on the limited available evidence, RT to set failure is likely not superior to non-failure RT for inducing muscle hypertrophy, but may exacerbate neuromuscular fatigue, muscle damage, and post-set perceived discomfort versus non-failure RT. Together, these factors may impair post-exercise recovery and subsequent performance, and may also negatively influence long-term adherence to RT.KEY POINTS This scoping review identified three broad themes of studies investigating proximity-to-failure in RT, based on the specific definition of set failure used (and therefore the research question being examined), to improve the validity of study comparisons and interpretations.There is no consensus definition for set failure in RT, and the proximity-to-failure achieved during non-failure RT is often unclear and varies both within and between studies, which together poses challenges when interpreting study findings and deriving practical recommendations regarding the influence of RT proximity-to-failure on muscle hypertrophy and other short-term responses.Based on the limited available evidence, performing RT to set failure is likely not superior to non-failure RT to maximise muscle hypertrophy, but the optimal proximity to failure in RT for muscle hypertrophy is unclear and may be moderated by other RT variables (e.g., load, volume-load). Also, RT performed to set failure likely induces greater neuromuscular fatigue, muscle damage, and perceived discomfort than non-failure RT, which may negatively influence RT performance, post-RT recovery, and long-term adherence.
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Affiliation(s)
- Martin C Refalo
- Centre for Sport Research (CSR), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Eric R Helms
- Sport Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand
| | - D Lee Hamilton
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, Australia
| | - Jackson J Fyfe
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, Australia
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