Hormone Function in Resistance Exercise: Training to Failure versus Non-Failure
In a unique recent study, Izquierdo et al. (2006) examined hormonal responses in an 11-week resistance training to failure (one group) vs. non-failure (second group) followed by an identical (both groups) 5-week peaking period of maximal strength and power protocol. Subjects were 42 physically active males randomly assigned to the two groups. The results showed that 11 weeks of training to failure and not-to-failure resulted in similar gains in 1RM strength, muscle power output of the arm and leg extensor muscles, and maximal number of repetitions in the squat. However, after the identical 5-week peaking period of maximal strength and power training, the non-failure group showed greater increases in strength, power, resting testosterone levels, and reduced coritsol levels when compared to the failure group. The failure group did have a greater increase in muscular endurance in bench press repetitions and a decrease in insulin-like growth factor 1 (IGF-1), a muscle building hormone.
Practical Application: Training to Failure versus Non-Failure
Taking each set to failure may not be as an important factor as once felt when trying to increase muscular strength, power, and hormonal response for clients. By taking each set to failure, a trainer may actually make clients more susceptible to overtraining and decreased hormonal and muscle power adaptations.
---------- Post added at 13:36:13 ---------- Previous post was at 13:35:35 ----------
Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men
Nicholas A. Burd1, Daniel W. D. West1, Aaron W. Staples1, Philip J. Atherton2, Jeff M. Baker1, Daniel R. Moore1, Andrew M. Holwerda1, Gianni Parise1,3, Michael J. Rennie2, Steven K. Baker4, Stuart M. Phillips1*
1 Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada, 2 School of Graduate Entry Medicine and Health, City Hospital, University of Nottingham, Derby, United Kingdom, 3 Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada, 4 Department of Neurology, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
Abstract
Background
We aimed to determine the effect of resistance exercise intensity (% 1 repetition maximum—1RM) and volume on muscle protein synthesis, anabolic signaling, and myogenic gene expression.
Methodology/Principal Findings
Fifteen men (21±1 years; BMI = 24.1±0.8 kg/m2) performed 4 sets of unilateral leg extension exercise at different exercise loads and/or volumes: 90% of repetition maximum (1RM) until volitional failure (90FAIL), 30% 1RM work-matched to 90%FAIL (30WM), or 30% 1RM performed until volitional failure (30FAIL). Infusion of [ring-13C6] phenylalanine with biopsies was used to measure rates of mixed (MIX), myofibrillar (MYO), and sarcoplasmic (SARC) protein synthesis at rest, and 4 h and 24 h after exercise. Exercise at 30WM induced a significant increase above rest in MIX (121%) and MYO (87%) protein synthesis at 4 h post-exercise and but at 24 h in the MIX only. The increase in the rate of protein synthesis in MIX and MYO at 4 h post-exercise with 90FAIL and 30FAIL was greater than 30WM, with no difference between these conditions; however, MYO remained elevated (199%) above rest at 24 h only in 30FAIL. There was a significant increase in AktSer473 at 24h in all conditions (P = 0.023) and mTORSer2448 phosphorylation at 4 h post-exercise (P = 0.025). Phosporylation of Erk1/2Tyr202/204, p70S6KThr389, and 4E-BP1Thr37/46 increased significantly (P<0.05) only in the 30FAIL condition at 4 h post-exercise, whereas, 4E-BP1Thr37/46 phosphorylation was greater 24 h after exercise than at rest in both 90FAIL (237%) and 30FAIL (312%) conditions. Pax7 mRNA expression increased at 24 h post-exercise (P = 0.02) regardless of condition. The mRNA expression of MyoD and myogenin were consistently elevated in the 30FAIL condition.
Conclusions/Significance
These results suggest that low-load high volume resistance exercise is more effective in inducing acute muscle anabolism than high-load low volume or work matched resistance exercise modes.
Citation: Burd NA, West DWD, Staples AW, Atherton PJ, Baker JM, et al. (2010) Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men. PLoS ONE 5(8): e12033. doi:10.1371/journal.pone.0012033
Editor: Alejandro Lucia, Universidad Europea de Madrid, Spain
Received: June 13, 2010; Accepted: July 14, 2010; Published: August 9, 2010
Copyright: © 2010 Burd et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by the Natural Sciences and Engineering Research Council of Canada (http://www.nserc-crsng.gc.ca/index_eng.asp). The funders had no role in study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: phillis@mcmaster.ca
http://www.plosone.org/article/info%...l.pone.0012033
---------- Post added at 13:42:39 ---------- Previous post was at 13:36:13 ----------
quest'ultimo è molto interessante.. praticamente 24h dopo l'allenamento solo il gruppo che ha utilizzato il 30% dell'1RM (carico basso) al fallimento ha protratto una sintesi proteica per le miofibrille mentre quelli del 90% dell'1RM (carico alto) no
---------- Post added at 13:43:11 ---------- Previous post was at 13:42:39 ----------
questo studio è riportato anche su wikipedia:
In a unique recent study, Izquierdo et al. (2006) examined hormonal responses in an 11-week resistance training to failure (one group) vs. non-failure (second group) followed by an identical (both groups) 5-week peaking period of maximal strength and power protocol. Subjects were 42 physically active males randomly assigned to the two groups. The results showed that 11 weeks of training to failure and not-to-failure resulted in similar gains in 1RM strength, muscle power output of the arm and leg extensor muscles, and maximal number of repetitions in the squat. However, after the identical 5-week peaking period of maximal strength and power training, the non-failure group showed greater increases in strength, power, resting testosterone levels, and reduced coritsol levels when compared to the failure group. The failure group did have a greater increase in muscular endurance in bench press repetitions and a decrease in insulin-like growth factor 1 (IGF-1), a muscle building hormone.
Practical Application: Training to Failure versus Non-Failure
Taking each set to failure may not be as an important factor as once felt when trying to increase muscular strength, power, and hormonal response for clients. By taking each set to failure, a trainer may actually make clients more susceptible to overtraining and decreased hormonal and muscle power adaptations.
---------- Post added at 13:36:13 ---------- Previous post was at 13:35:35 ----------
Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men
Nicholas A. Burd1, Daniel W. D. West1, Aaron W. Staples1, Philip J. Atherton2, Jeff M. Baker1, Daniel R. Moore1, Andrew M. Holwerda1, Gianni Parise1,3, Michael J. Rennie2, Steven K. Baker4, Stuart M. Phillips1*
1 Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada, 2 School of Graduate Entry Medicine and Health, City Hospital, University of Nottingham, Derby, United Kingdom, 3 Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada, 4 Department of Neurology, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
Abstract
Background
We aimed to determine the effect of resistance exercise intensity (% 1 repetition maximum—1RM) and volume on muscle protein synthesis, anabolic signaling, and myogenic gene expression.
Methodology/Principal Findings
Fifteen men (21±1 years; BMI = 24.1±0.8 kg/m2) performed 4 sets of unilateral leg extension exercise at different exercise loads and/or volumes: 90% of repetition maximum (1RM) until volitional failure (90FAIL), 30% 1RM work-matched to 90%FAIL (30WM), or 30% 1RM performed until volitional failure (30FAIL). Infusion of [ring-13C6] phenylalanine with biopsies was used to measure rates of mixed (MIX), myofibrillar (MYO), and sarcoplasmic (SARC) protein synthesis at rest, and 4 h and 24 h after exercise. Exercise at 30WM induced a significant increase above rest in MIX (121%) and MYO (87%) protein synthesis at 4 h post-exercise and but at 24 h in the MIX only. The increase in the rate of protein synthesis in MIX and MYO at 4 h post-exercise with 90FAIL and 30FAIL was greater than 30WM, with no difference between these conditions; however, MYO remained elevated (199%) above rest at 24 h only in 30FAIL. There was a significant increase in AktSer473 at 24h in all conditions (P = 0.023) and mTORSer2448 phosphorylation at 4 h post-exercise (P = 0.025). Phosporylation of Erk1/2Tyr202/204, p70S6KThr389, and 4E-BP1Thr37/46 increased significantly (P<0.05) only in the 30FAIL condition at 4 h post-exercise, whereas, 4E-BP1Thr37/46 phosphorylation was greater 24 h after exercise than at rest in both 90FAIL (237%) and 30FAIL (312%) conditions. Pax7 mRNA expression increased at 24 h post-exercise (P = 0.02) regardless of condition. The mRNA expression of MyoD and myogenin were consistently elevated in the 30FAIL condition.
Conclusions/Significance
These results suggest that low-load high volume resistance exercise is more effective in inducing acute muscle anabolism than high-load low volume or work matched resistance exercise modes.
Citation: Burd NA, West DWD, Staples AW, Atherton PJ, Baker JM, et al. (2010) Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men. PLoS ONE 5(8): e12033. doi:10.1371/journal.pone.0012033
Editor: Alejandro Lucia, Universidad Europea de Madrid, Spain
Received: June 13, 2010; Accepted: July 14, 2010; Published: August 9, 2010
Copyright: © 2010 Burd et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by the Natural Sciences and Engineering Research Council of Canada (http://www.nserc-crsng.gc.ca/index_eng.asp). The funders had no role in study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: phillis@mcmaster.ca
http://www.plosone.org/article/info%...l.pone.0012033
---------- Post added at 13:42:39 ---------- Previous post was at 13:36:13 ----------
quest'ultimo è molto interessante.. praticamente 24h dopo l'allenamento solo il gruppo che ha utilizzato il 30% dell'1RM (carico basso) al fallimento ha protratto una sintesi proteica per le miofibrille mentre quelli del 90% dell'1RM (carico alto) no
---------- Post added at 13:43:11 ---------- Previous post was at 13:42:39 ----------
questo studio è riportato anche su wikipedia:
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