Article

Partial range of motion exercise is effective for facilitating muscle hypertrophy and function via sustained intramuscular hypoxia in young trained men

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  • Tokyo Medical University, Tokyo
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Abstract

Goto, M, Chikako, M, Hirayama, T, Terada, S, Nirengi, S, Kurosawa, Y, Nagano, A, and Hamaoka, T. Partial range of motion exercise is effective for facilitating muscle hypertrophy and function through sustained intramuscular hypoxia in young trained men. J Strength Cond Res 33(5): 1286-1294, 2019-The acute response to and long-term effects of partial range of motion exercise (PRE) and full range of motion exercise (FRE) of elbow extensors were compared in young trained men. The PRE was expected to increase the intramuscular hypoxic environment, which was theorized to enhance muscular hypertrophy. Forty-four resistance-trained men were divided into 2 training groups, PRE (n = 22) or FRE (n = 22) group, and performed the PRE or FRE acute exercise protocol. The PRE (elbow range from 45° to 90°) and FRE (from 0° to 120°) acute protocols consisted of 3 sets of 8 repetitions, with an 8RM, and an equivalent workload. After the initial testing, the training program for each group, comprised 3 training sessions per week for 8 weeks, was started. The acute responses of area under the oxygenated hemoglobin (Oxy-Hb) curve, blood lactate concentration, and root mean square of electromyography were significantly higher both before and after PRE than FRE training. Long-term effects were produced by both PRE and FRE, with significant (p ≤ 0.05) increases in cross-sectional area (CSA) of triceps brachii and isometric strength. The CSA increased significantly greater after PRE (48.7 ± 14.5%) than after FRE (28.2 ± 10.9%). Furthermore, during the PRE program, a positive correlation was detected between the percent increase in CSA and area under the Oxy-Hb curves before and after 8-week exercise training (before 8-week exercise training: r = 0.59, after 8-week exercise training: r = 0.70, p < 0.01). These results suggest that intramuscular hypoxia might facilitate muscular hypertrophy with PRE being more effective than FRE.

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... Given that resistance training adaptations are specific to the mode or variable of training performed (20), it is necessary to implement these variables in a planned fashion specific to the goals of the athlete or team performing the program. Common training variables used in resistance training programs include repetition ranges (61), training intensity (39,61), training frequency (63), contraction speed emphasized (52,62), loading patterns (33,70), and even the joint range of motion used (5,19,32,38,55,59,68) in resistance training exercises. ...
... Researchers can measure strength training range of motion through a small variety of tools. The primary measurement method has centered on assessing the degrees of rotation performed at a specific joint (5,19,32,38,55,68). In addition, resistance implement displacement has also been used in research (26) albeit to a lesser extent. ...
... Indeed, previous studies have consistently used greater ranges of motion or deeper positions of joint flexion to assess muscles at "long" lengths, whereas shorter ranges of motion or more shallow joint angles represent "short" muscle lengths (19,37,38,47,55,57,59). Certainly, the change in joint angle does not perfectly correlate with a change in muscle length because this relationship can be affected by muscle activation (48,64), contraction/movement velocity (43), and muscle pennation angle and resultant architectural gear ratios (64). ...
Article
One resistance training variable that may be altered to achieve desired outcomes is the range of motion used in training. Generally, the strength and conditioning field has accepted that using a greater range of motion in strength training exercises results in more substantial muscle hypertrophy outcomes. However, this theory has proved to be inconsistently supported in the literature, and to date, no sufficient explanation exists to explain this phenomenon. This review article seeks to outline a novel approach for potentially describing the disparities seen in range of motion research with respect to hypertrophy outcomes by applying the unique length tension curve of each muscle being examined. As will be discussed in the review, virtually all the results from range of motion studies in various muscles have corresponded to each muscle’s length-tension curve; muscles that are active on the descending limb of the curve appear to garner greater hypertrophy from using larger ranges of motion. Conversely, muscles that are not active on the descending limb exhibit similar adaptations despite alterations in range of motion. A novel hypothesis for applying this information to resistance training programs will be presented and discussed.
... The full texts of these articles were then screened and 6 were identified as meeting inclusion criteria. [16][17][18][19][20][21] All included studies tallied 6 points on the PEDro checklist and thus were classified as being of "excellent" methodological quality. Figure 1 provides a flow chart of the search process. ...
... Five of the studies included untrained individuals as study participants [17][18][19][20][21] and one study 16 involved trained individuals. The total combined sample of the studies was n = 135, which comprised 127 men and 8 women. ...
... As previously noted, only two studies have explored the effects of training with full versus partial ROM in RT on muscle hypertrophy in the upper extremities. In one study, Goto et al. 16 observed that training with a partial ROM promoted greater increases in muscle size of the elbow extensors than training with a full ROM. Alternatively, results from Pinto et al. 17 showed modest hypertrophic benefits for full versus partial ROM (9.7% vs. 7.8%; p = 0.07). ...
Article
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The purpose of this study was to systematically review the literature as to the effects of performing exercise with a full vs. partial range of motion (ROM) during dynamic, longitudinal resistance training (RT) programs on changes in muscle hypertrophy. Based on the available evidence, we aimed to draw evidence-based recommendations for RT prescription. Six studies were identified as meeting inclusion criteria: four of these studies involved RT for the lower limbs while the other two focused on the upper extremities. The total combined sample of the studies was n = 135, which comprised 127 men and 8 women. The methodological quality of all included studies was deemed to be “excellent” based on the modified PEDro scale. When assessing the current body of literature, it can be inferred that performing RT through a full ROM confers beneficial effects on hypertrophy of the lower body musculature vs. training with a partial ROM. Alternatively, research on the effects of ROM for the upper limbs is limited and conflicting, precluding the ability to draw strong practical inferences. No study to date has investigated how ROM influences muscle growth of the trunk musculature. Finally, some evidence indicates that the response to variations in ROM may be muscle-specific; however, this hypothesis also warrants further study.
... Whilst, both pROM and fROM RT produce improvements in muscle size, it has been reported that fROM RT is more efficacious for promoting muscle hypertrophy in the lower body [3]. Evidence in the upper body is more equivocal [5,6] and research has not been consolidated in review. Similarly, in regard to performance outcomes such as strength, both pROM and fROM RT have been shown to stimulate improvements [7][8][9]. ...
... In addition, it has been suggested that pROM RT may promote greater muscle deoxygenation and greater blood lactate accumulation compared to fROM RT [6]. Mechanistically, these differences in acute responses to ROM may lead to divergent training adaptations [12,13]. ...
Preprint
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Background: Range of motion (ROM) during resistance training is of growing interest and is potentially used to elicit differing adaptations (e.g. muscle hypertrophy and muscular strength and power). To date, attempts at synthesising the data on ROM during resistance training have primarily focused on muscle hypertrophy in the lower body. Objective: Our aim was to meta-analyse and systematically review the effects of ROM on a variety of outcomes including hypertrophy, strength, sport, power and body-fat type outcomes. Following pre-registration and consistent with PRISMA guidelines, a systematic review of PubMed and SportsDISCUS was performed. Data was extracted and a Bayesian multi-level meta-analysis was performed. A range of exploratory subgroup and moderator analyses were performed. Results: The main model revealed a trivial SMD (0.13; 95% CI: −0.01, 0.27) in favour of full ROM compared to partial ROM. When grouped by outcome, SMDs all favoured full ROM, but SMDs were trivial to small (all between 0.05 to 0.2). Subgroup analyses suggested there may be a muscle hypertrophy benefit to partial ROM training at long muscle lengths compared to using a full ROM (SMD=−0.28, 95% CI: −0.81, 0.16). Analysis also suggested the existence of a specificity aspect to ROM, such that training in the ROM being tested as an outcome resulted in greater strength adaptations. No clear differences were found between upper-and lower-body adaptations when ROM was manipulated. Conclusions: Overall, our results suggest that using a full or long ROM may enhance results for most outcomes (strength, speed, power, muscle size, and body composition). Differences in adaptations are trivial to small. As such, partial ROM resistance training might present an efficacious alternative for variation and personal preference, or where injury prevents full-ROM resistance training.
... In general, researchers have demonstrated that slower tempos are associated with greater hormonal response (Goto et al. 2008;Headley et al. 2011), higher blood lactate concentration Wilk et al. 2021), and lower levels of muscle oxygenation (Tanimoto and Ishii 2006;Tanimoto et al. 2008). The latter is an important factor to consider because local tissue hypoxia has been implicated in skeletal muscle hypertrophy (Goto et al. 2019), angiogenesis (Ferguson et al. 2017), and improved oxidative capacity (Ferguson et al. 2021). Regardless, a common confounding variable of the available research on repetition tempo is that TUT (Goto et al. 2008;Headley et al. 2011;Martins-Costa et al. 2016;Wilk et al. 2021) and/or proximity to concentric muscular failure (i.e., effort) were not matched between protocols with different tempos (Tanimoto and Ishii 2006) making it difficult to isolate the effect of tempo on metabolic stress. ...
... This result supports previous research where faster tempos led to greater blood lactate concentration than slower tempos when TUT was matched at 36 s (Lacerda et al. 2016) and 60 s (Vargas-Molina et al. 2020). Although speculative, it is possible that training with more repetitions (20 vs. 10) and shorter concentric phases (1 vs. 2 s) involves more frequent and forceful contractions that recruit higher-threshold motor units with more glycolytic fibers which produce more anaerobic products (Carpinelli, 2008;Goto et al. 2019;Lacerda et al. 2016;Mazzetti et al. 2007). This speculation is further supported by evidence that training with faster tempos resulted in greater motor unit recruitment, as indicated by higher electromyographic responses (Lacerda et al. 2016) and higher energy expenditure (Mazzetti et al. 2007). ...
Article
Full-text available
Purpose To investigate the effect of repetition tempo on cardiovascular and metabolic stress when time under tension (TUT) and effort are matched during sessions of lower body resistance training (RT). Methods In a repeated-measures, cross-over design, 11 recreationally trained females (n = 5) and males (n = 6) performed 5 sets of belt squats under the following conditions: slow-repetition tempo (SLOW; 10 reps with 4-s eccentric and 2-s concentric) and traditional-repetition tempo (TRAD; 20 reps with 2-s eccentric and 1-s concentric). TUT (60 s) was matched between conditions and external load was adjusted so that lifters were close to concentric muscular failure at the end of each set. External load, total volume load (TVL), impulse (IMP), blood lactate, ratings of perceived exertion (RPE), HR, and muscle oxygenation were measured. Results Data indicated that TVL (p < 0.001), blood lactate (p = 0.017), RPE (p = 0.015), and HR (p < 0.001) were significantly greater during TRAD while external load (p = 0.030) and IMP (p = 0.002) were significantly greater during SLOW. Whether it was expressed as minimal values or change scores, muscle oxygenation was not different between protocols. Conclusion When TUT is matched, TVL, cardiovascular stress, metabolic stress, and perceived exertion are greater when faster repetition tempos are used. In contrast, IMP and external load are greater when slower repetition tempos are used.
... In general, to apply greater metabolic stress on working muscles, intramuscular hypoxia caused by resistance exercise is a key element to stimulate the secretion of growth hormones and testosterone in relation to muscle hypertrophy 6) . Recently, a positive correlation was found between the level of intramuscular hypoxia during resistance exercise and the rate of muscle hypertrophy 7) . ...
... The lower % baseline oxy-Hb/Mb level during resistance exercise and longer T1/2 reoxy time in intervals between sets in the cold pack were due to high muscular activation. Goto et al. 7) compared the effects of resistance exercise on the % MVC-RMS of EMG and intramuscular hypoxia between total range of motion exercise and partial range of motion exercise. They concluded that the myoelectric activity and intramuscular hypoxia during partial range of motion exercise were higher than those during total range of motion exercise, and a higher degree of intramuscular hypoxia resulted in a greater isometric contraction force and muscle CSA after eight weeks, demonstrating a positive correlation. ...
Article
[Purpose] The purpose of this study was to determine the efficacy of using a cold pack while doing resistance exercises for enhancing muscle strength and muscle hypertrophy through decreased intramuscular oxygenation and/or increased myoelectric activity. [Participants and Methods] Twenty-four resistance-trained males (age: 26.4 ± 8.4 years, height: 169.3 ± 5.2 cm, body weight: 74.7 ± 8.8 kg) involved in this study. All the participants completed two experimental sessions in random order (cold pack resistance exercise and resistance exercise) with a 3-day interval. Four types of resistance exercises (4 sets × 8 repetitions with an 8-repetition maximum) targeting the right triceps brachii muscle were performed in both the experimental sessions. [Results] The percentage baseline oxyhemoglobin/myoglobin level during resistance exercise was significantly lower, the half-recovery time of muscle oxygenation in intervals between sets was significantly longer, and the myoelectric activity was significantly higher in the cold pack resistance exercise than in the resistance exercise session. [Conclusion] The results suggest that using a cold pack with resistance exercises is effective in inducing intramuscular deoxygenation and increasing myoelectric activity and may be useful for increasing muscle strength and inducing hypertrophy.
... Therefore, bearing in mind the above-mentioned aspects and according to Wilk et al. 4,5 , time under tension might be the most reliable indicator to assess exercise volume in resistance exercise regardless of the number of performed REPs and desired ROM. The effects of the ROM on training outcomes have been widely analyzed [7][8][9][10][11][12][13] . A study by Martínez-Cava et al. 11,12 indicated that the mean velocity achieved against a wide range of loads was significantly higher, with a greater ROM during resistance exercises. ...
... These findings should be taken into account especially when designing research procedures comparing the effectiveness of different ROM in a given exercise on the training outcomes. The results of this type of studies rather indicated a superior effect of the full ROM compared to the partial one on muscle development [10][11][12][13]29 , with some exceptions 8,9 . However, only one of these studies equalized the training volume to the time under tension 8 or load-displacement 10 while the vast majority did so based on the number of Table 3. Differences in performance variables during a standard and cambered barbell bench press. ...
Article
Full-text available
Abstract The resistance training volume along with the exercise range of motion has a significant impact on the training outcomes. Therefore, this study aimed to examine differences in training volume assessed by a number of performed repetitions, time under tension, and load–displacement as well as peak barbell velocity between the cambered and standard barbell bench press training session. The participants performed 3 sets to muscular failure of bench press exercise with the cambered or standard barbell at 50% of one-repetition maximum (1RM). Eighteen healthy men volunteered for the study (age = 25 ± 2 years; body mass = 92.1 ± 9.9 kg; experience in resistance training 7.3 ± 2.1 years; standard and cambered barbell bench press 1RM > 120% body mass). The t-test indicated a significantly higher mean range of motion for the cambered barbell in comparison to the standard (p
... After the full-text screening, 16 studies were considered for qualitative analysis and meta-analyses. [53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] Two authors provided missing data not published in the original studies. 54,60 ...
... Our results are in line with a previous systematic review 35 suggesting a potential greater effect of full ROM resistance training on muscle hypertrophy, especially in the lower limbs. 54,56,64,66 It is worth noting that, except for Goto et al. 58 (muscle size measured at a single point of the muscle length), the rest of the investigations used as an indicator of muscle hypertrophy either the muscle volume 54,66 or CSA measurements acquired at different lengths of the target muscle (eg, proximal-medial-distal). 54,56,64 Although the assessment of the muscle volume via MRI would be the gold-standard technique, 80 measuring the CSA at different points would allow researchers to identify regional changes which would be dependent on the exercise trained (eg, leg press and knee extension would maximize hypertrophy in the middle 81 and distal sites 39 of the muscle, respectively). Therefore, the results found by the current study regarding the superior effectiveness of the full ROM in generating 39 muscle growth has been proved to be influenced by the duration of the training program in a linear fashion (ie, the longer the duration, the more muscle hypertrophy). ...
Article
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Background Nowadays, there is a lack of consensus and high controversy about the most effective range of motion (ROM) to minimize the risk of injury and maximize the resistance training adaptations. Objective To conduct a systematic review and meta-analysis of the scientific evidence examining the effects of full and partial ROM resistance training interventions on neuromuscular, functional, and structural adaptations. Methods The original protocol (CRD42020160976) was prospectively registered in the PROSPERO database. Medline, Scopus, and Web of Science databases were searched to identify relevant articles from the earliest record up to and including August 2020. The RoB 2 and GRADE tools were used to judge the level of bias and quality of evidence. Meta-analyses were performed using robust variance estimation with small-sample corrections. Results Sixteen studies were finally included in the systematic review and meta-analyses. Full ROM training produced significantly greater adaptations than partial ROM on muscle strength (ES=0.56, P=0.004) and lower-limb hypertrophy (ES=0.88, P=0.027). Furthermore, although not statistically significant, changes in functional performance were maximized by the full ROM training (ES=0.44, P=0.186). Finally, no significant superiority of either ROM was found to produce changes in muscle thickness, pennation angle, and fascicle length (ES=0.28, P=0.226). Conclusion Full ROM resistance training is more effective than partial ROM to maximize muscle strength and lower-limb muscle hypertrophy. Likewise, functional performance appears to be favored by the use of full ROM exercises. On the other hand, there are no large differences between the full and partial ROM interventions to generate changes in muscle architecture.
... However, on the other hand, greater metabolic stress may be obtained when focusing the exercise execution training with short lengths [29]. Thus, the balance between lower and greater torque at the distinct phases of the movement (i.e., lower torque for CAB and greater for BAR at the initial angles; ...
... However, in another experiment, after training protocols at longer (0-90° of knee flexion) and shorter (0-50°) average muscle lengths, the authors showed an evident advantage for training at longer muscle lengths only at the distal site of the vastus lateralis [27]. Together, these results indicate that a clear benefit for training at long muscle lengths may occur only when training in that length in an isolated manner, and in comparison to shorter isolated ones [13,16,20,27,29,30]; so that the slight difference produced by the present exercise setups was not sufficient to elicit different adaptations. ...
Article
Full-text available
Muscular strength and hypertrophy following resistance training may be obtained in different degrees depending on the approach performed. This study was designed to compare the responses of the biceps brachii to two preacher curl exercises, one performed on a cable-pulley system (CAB; in which a greater torque was applied during the exercise when elbows were flexed and biceps shortened) and one performed with a barbell (BAR; in which greater torque was applied when the elbows were extended and biceps stretched). Thirty-five young adults (CAB: 13 men, 5 women; BAR: 12 men, 5 women; age = 24 ± 5 years) performed a resistance training program three times per week for 10 weeks, with preacher curl exercises performed in 3 sets of 8-12 repetitions. Outcomes measured included elbow flexion peak isokinetic torque at angles 20°, 60°, and 100° (considering 0° as elbow extended), and biceps brachii thickness (B-mode ultrasound). Following training period, there were observed significant increases for both groups in elbow flexion peak torque at the 20° (CAB: 30%; BAR = 39%; P = 0.046), 60° (CAB: 27%; BAR = 32%; P = 0.874), and 100° (CAB: 17%; BAR = 19%; P = 0.728), and biceps brachii thickness (CAB: 7%; BAR = 8%; P = 0.346). In conclusion, gains in muscular strength were greater for BAR only at longer muscle length, whereas hypertrophy was similar regardless if torque emphasis was carried out in final (CAB) or initial (BAR) degrees of the range of motion of preacher curl in young adults.
... Previous studies suggest that multiple exercise, moderate to high load (65-85% of 1 repetition maximum), 6 to 12 repetitions, slower speed (2-4 seconds) for both concentric and eccentric contractions, 3 to 5 sets, and intervals between sets within 60-90 seconds are optional for a resistance exercise protocol targeting muscle hypertrophy (Schoenfeld, 2010). This resistance exercise protocol induces metabolic changes such as increased hydrogen iron concentration (Cheema et al., 2014), production of reactive oxygen species (Powers et al., 2011), promotion of intramuscular hypoxia, and increased blood lactate concentration (Goto et al., 2019). As these intramuscular metabolic changes disturb regular muscle contraction, interstitial fluid accumulates in the plasma membrane of the muscle to buffer these metabolites, increasing intracellular hydration (Sjogaard, 1998). ...
... The reason for muscle CSA and intracellular hydration at 5 minutes after resistance exercise in resistance-trained group being greater than that in untrained group might be due to differences in original muscle size, resistance exercise-induced metabolic responses, and motor unit activation between two groups. Sustained intramuscular hypoxia is facilitated by intramuscular capillary compression with greater muscle contraction (Goto et al., 2019). As a result, the glycolysis metabolism might be promoted and post resistance exercise intracellular hydration and muscle CSA might increase (Frigeri et al., 1998). ...
Article
Full-text available
The purpose of this study was to compare the temporal increase in muscle cross-sectional area (CSA) as the acute response of resistance exercise (RE) between resistance-trained and untrained groups and investigate the factors that affect the muscle CSA. Resistance-trained (n = 14) and untrained (n = 14) subjects performed four kinds of triceps brachii RE. Muscle CSA and intracellular hydration (IH), were measured prior to and 5-, 30-, and 60-minute after RE. Pearson's correlation coefficient was calculated to clarify the relationships among percent increases in muscle CSA and IH, area under the Oyx-Hb curve, blood lactate concentration, and % maximum voluntary contraction (MVC)-root-mean-square (RMS) of electromyogram (EMG). At 5-minute after RE, muscle CSA increased significantly to 120.2 ± 6.3% in the resistance-trained group and 105.5 ± 2.3% in the untrained group (p < .01). However, neither group showed a significant difference between the values before and 30-minute after RE. In the resistance-trained group, there was a significant increase in IH at 5-minute post-RH (p < .01), and correlations were found between percent increases in muscle CSA and IH (r = 0.70, p < .01), area under the Oxy-Hb curve (r = 0.77, p < .01), and % MVC-RMS of EMG (r = 0.72, p < .01). The findings of this study suggest that measurements of muscle CSA in studies of muscle hypertrophy should be performed 30-minute or more after the last resistance exercise session, and muscle pump exercises should be conducted just before participation in bodybuilding, and physique contests.
... Similarly to our study, the participants performed the exercises three days a week for eight weeks. They concluded that range of motion exercises facilitate muscle hypertrophy positively (Goto et al., 2019). Moradi et al. implemented an eight-week exercise program in their study examining male volleyball players with internal rotation deficit in the shoulder. ...
Article
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Background. Resistance-trained males aim to increase their overall health, strength and fitness level. Many resistance-trained males aiming to increase their strength neglect the muscles that stabilize the scapular and glenohumeral joints. The shoulder joint is among the most frequently injured areas in resistance-trained males. In addition, strength training displays different effects in young and old individuals. The study purpose was to investigate the effects of stability and mobility exercises on range of motion, posture and body awareness in resistance-trained males with shoulder immobility. Materials and methods. Thirty-two resistance-trained males diagnosed with shoulder immobility were divided into two groups according to their age ranges (G1: Adult, G2: Young Adult). The program consisting of mobility and stability exercises was applied 3 days a week for 8 weeks. The participants were evaluated with a universal goniometer, the New York Posture Rating, and the Body Awareness Questionnaire before and after the treatment lasting 8 weeks. Results. Following the 8-week treatment, improvements in body awareness and range of motion were observed in all participants (p≤0.05). There were improvements in the scores of the New York Posture Rating and Body Awareness Questionnaire in both groups, but they were not statistically significant (p≥0.05). Conclusions. An exercise program combining stability and mobility exercises was applied to resistance-trained males with shoulder immobility and it was observed to have positive effects on the range of motion of the joint, body awareness and posture. We are of the opinion that various types of exercise should be implemented when planning exercise programs.
... Pinto et al. (2012) reported that the increase in elbow flexion one-repetition maximum (1-RM) strength was significantly greater after a full ROM (0 • -130 • elbow flexion) protocol (26%) than a partial ROM (50 • -100 • elbow flexion) protocol (16%), but the increase in brachialis plus biceps thickness was similar between the full (10%) and partial ROM (8%) groups. Goto et al. (2019) compared a full ROM (0 • -120 • elbow flexion) and a partial ROM (45 • -90 • elbow flexion) triceps extension resistance training for changes in muscle strength and muscle cross-sectional area (CSA) of the elbow extensors performed by resistance-trained men three times a week for 8 weeks. They showed that the partial ROM group had significantly greater increases in maximum voluntary contraction (MVC) torque (40%) and CSA (49%) than the full ROM group (24, 28%). ...
Article
Background: Postural balance represents a fundamental movement skill for the successful performance of everyday and sport-related activities. There is ample evidence on the effectiveness of balance training on balance performance in athletic and non-athletic population. However, less is known on potential transfer effects of other training types, such as plyometric jump training (PJT) on measures of balance. Given that PJT is a highly dynamic exercise mode with various forms of jump-landing tasks, high levels of postural control are needed to successfully perform PJT exercises. Accordingly, PJT has the potential to not only improve measures of muscle strength and power but also balance. Objective: To systematically review and synthetize evidence from randomized and non-randomized controlled trials regarding the effects of PJT on measures of balance in apparently healthy participants. Methods: Systematic literature searches were performed in the electronic databases PubMed, Web of Science, and SCOPUS. A PICOS approach was applied to define inclusion criteria, (i) apparently healthy participants, with no restrictions on their fitness level, sex, or age, (ii) a PJT program, (iii) active controls (any sport-related activity) or specific active controls (a specific exercise type such as balance training), (iv) assessment of dynamic, static balance pre- and post-PJT, (v) randomized controlled trials and controlled trials. The methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. This meta-analysis was computed using the inverse variance random-effects model. The significance level was set at p < 0.05. Results: The initial search retrieved 8,251 plus 23 records identified through other sources. Forty-two articles met our inclusion criteria for qualitative and 38 for quantitative analysis (1,806 participants [990 males, 816 females], age range 9–63 years). PJT interventions lasted between 4 and 36 weeks. The median PEDro score was 6 and no study had low methodological quality (�3). The analysis revealed significant small effects of PJT on overall (dynamic and static) balance (ES = 0.46; 95% CI = 0.32–0.61; p < 0.001), dynamic (e.g., Y-balance test) balance (ES = 0.50; 95% CI = 0.30–0.71; p < 0.001), and static (e.g., flamingo balance test) balance (ES = 0.49; 95% CI = 0.31–0.67; p<0.001). The moderator analyses revealed that sex and/or age did not moderate balance performance outcomes. When PJT was compared to specific active controls (i.e., participants undergoing balance training, whole body vibration training, resistance training), both PJT and alternative training methods showed similar effects on overall (dynamic and static) balance (p = 0.534). Specifically, when PJT was compared to balance training, both training types showed similar effects on overall (dynamic and static) balance (p = 0.514). Conclusion: Compared to active controls, PJT showed small effects on overall balance, dynamic and static balance. Additionally, PJT produced similar balance improvements compared to other training types (i.e., balance training). Although PJT is widely used in athletic and recreational sport settings to improve athletes’ physical fitness (e.g., jumping; sprinting), our systematic review with meta-analysis is novel in as much as it indicates that PJT also improves balance performance. The observed PJT-related balance enhancements were irrespective of sex and participants’ age. Therefore, PJT appears to be an adequate training regime to improve balance in both, athletic and recreational settings.
... Pinto et al. (2012) reported that the increase in elbow flexion one-repetition maximum (1-RM) strength was significantly greater after a full ROM (0 • -130 • elbow flexion) protocol (26%) than a partial ROM (50 • -100 • elbow flexion) protocol (16%), but the increase in brachialis plus biceps thickness was similar between the full (10%) and partial ROM (8%) groups. Goto et al. (2019) compared a full ROM (0 • -120 • elbow flexion) and a partial ROM (45 • -90 • elbow flexion) triceps extension resistance training for changes in muscle strength and muscle cross-sectional area (CSA) of the elbow extensors performed by resistance-trained men three times a week for 8 weeks. They showed that the partial ROM group had significantly greater increases in maximum voluntary contraction (MVC) torque (40%) and CSA (49%) than the full ROM group (24, 28%). ...
Article
Studies comparing children and adolescents from different periods have shown that physical activity and fitness decreased in the last decades, which might have important adverse health consequences such as body fat gain and poor metabolic health. The purpose of the current article is to present the benefits of high-intensity multimodal training (HIMT), such as CrossFit, to young people, with a critical discussion about its potential benefits and concerns. During HIMT, exercise professionals might have an opportunity to promote positive changes in physical function and body composition in children and adolescents, as well as to promote improvements in mental health and psychosocial aspects. Moreover, this might serve as an opportunity to educate them about the benefits of a healthy lifestyle and overcome the perceived barriers for being physically active. In technical terms, the characteristics of HIMT, such as, the simultaneous development of many physical capacities and diversity of movement skills and exercise modalities might be particularly interesting for training young people. Many concerns like an increased risk of injury and insufficient recovery might be easily addressed and not become a relevant problem for this group.
... In support of partial ROM, Goto et al. (2019) investigated if partial ROM RE is effective in inducing muscle hypertrophy and function. They hypothesized that partial ROM training induces higher vascular occlusion than full ROM training, mediated through greater muscular tension and constant contractions, resulting in increased hypertrophy and strength in resistancetrained men. ...
Article
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Skeletal muscle is one of the most important tissues of the human body. It comprises up to 40% of the body mass and is crucial to survival. Hence, the maintenance of skeletal muscle mass and strength is pivotal. It is well-established that resistance exercise provides a potent anabolic stimulus to increase muscle mass and strength in men and women of all ages. Resistance exercise consists of mechano-biological descriptors, such as load, muscle action, number of repetitions, repetition duration, number of sets, rest interval between sets, frequency, volitional muscular failure, and range of motion, which can be manipulated. Herein, we discuss the evidence-based contribution of these mechano-biological descriptors to muscle mass and strength.
... The decrease in the activation value with the increase of the eccentric contraction length may be one of them (Enoka, 1996). In a study supporting this situation in the literature, it was determined that triceps brachii muscle activation was higher in partial range of motion (from 45° to 90°) exercise than in full range of motion exercise (from 0° to 90°) (Goto et al., 2019). In another study, elbow joint angle was examined during bench press exercise and it was determined that the highest triceps brachii EMGPEAK value was in the middle of the concentric phase (Lacerda et al., 2020). ...
Article
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The parallel bar dip is one of the most commonly used calisthenic exercises. However, a recommended elbow angle in terms of activation patterns has not yet been studied. The aim of this study is to examine the activation values of the pectoralis major and triceps muscle groups during parallel bar dip at different elbow angles. Ten male volunteers (age: 25.1 ± 3.9 years) with regular exercise habits participated in the study. During the parallel bar dip, the pectoralis major, lateral triceps and long triceps muscles were examined at elbow angles of 75°, 85° and 95°. The movement was standardized using the metronome (60 beats.min-1) and evaluated in three phases (eccentric = 2 seconds, isometric = 1 seconds, concentric = 2 seconds). There was no statistically significant difference between the angles for pectoralis major (p>0.05). Significant differences were observed in triceps muscle groups, especially in favor of 75° in the isometric phase (p<0.05). The greatest activation in terms of phases was seen in concentric contraction for all muscles. This research has shown that the reduction of the elbow flexion angle has a positive effect on the activation of triceps muscle group. However, since there are some methodological limitations (such as biomechanical markers), it can be said that future research should improve these findings.
... However, a greater ROM allows for a higher velocity of movement (Drinkwater et al., 2012;, and recently conducted studies have found that full ROMs after resistance training produces greater neuromuscular adaptations than partial movements (Martínez-Cava, Hernández-Belmonte, et al., 2019;Pallarés et al., 2020). Therefore, the optimal ROM is still a matter of debate in the fitness society (Goto et al., 2019). ...
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Background/objective: The aim of this study was to examine differences in bar velocity between the cambered and standard barbell bench press exercise. Methods: Ten healthy men volunteered for the study (age = 27.9 ± 3.7 years; body mass = 89.6 ± 11.7 kg; experience in resistance training 5.7 ± 2.1 years; bench press one-repetition maximum > 120% body mass). The first session aiming at the determination of the one-repetition maximum was followed by two experimental sessions consisted of performing 3 sets of 3 repetitions of the bench press exercise with the cambered or standard barbell at 50% of one-repetition maximum (of the standard barbell) in randomized order. Results: The two-way repeated measures ANOVA indicated a significant main effect of bar type on mean velocity (p=0.001; η 2 =0.739) and peak velocity (p=0.002; η 2 =0.661). The post-hoc analysis showed a significantly higher mean velocity for the cambered barbell compared to the standard barbell bench press in Set 1 (p=0.002) and Set 2 (p=0.012), but not in Set 3 (p=0.062). Moreover, there was a significantly higher mean velocity in Set 2, than in Set 1 (p=0.017) during the standard barbell bench press, with no other differences. Furthermore, a significantly higher peak velocity for the cambered barbell in comparison to the standard barbell was observed in all sets of the BP exercise (p<0.001; p=0.014; p=0.048; respectively). Conclusions: The outcomes of this investigation indicated that the cambered barbell used during the bench press training session significantly increases bar velocity compared to the standard barbell with the same external load across the workout.
... The MT of all quadriceps muscles increased in response to squat training, regardless of condition, probably as a result of the muscle pump mechanisms mentioned earlier (Schoenfeld, 2013b;Goto et al., 2019). The acute increase in RF thickness in both resistance exercise conditions may be attributed to a swelling effect after performance of the bilateral squat. ...
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Background: Bilateral squat exercise is widely used in resistance training (RT) programs to increase lower limb strength and muscle mass, but this exercise does not result in significant hypertrophy of the hamstrings. It has been speculated that stretching between sets with a certain degree of tension results in muscle hypertrophy, while acute stretching could decrease performance during maximal contractions. Objective: This study investigated the acute effects of hamstring stretching before bilateral squatting on muscle thickness (MT), electromyography (EMG), and total training volume (TTV) on exercise performance. Methods: Fourteen resistance-trained young men, with ∼7.5 years of RT experience, performed the 10 repetition maximum (RM) for the barbell squat in two sessions (test–retest) separated by period after 48 h. Participants engaged in two resistance exercise conditions separated by a 1 week recovery interval: one session employed hamstrings stretching and the other did not include hamstrings stretching. Before and after each resistance exercise session, the thickness of the quadriceps muscles and biceps femoris long head were obtained by ultrasound imaging. Moreover, the EMG amplitudes for the quadriceps muscles, biceps femoris, and iliocostalis muscles were recorded during back squat performance. The TTV was also evaluated for each exercise session. Results: A significant increase in MT was observed after every set in both conditions for the evaluated quadriceps muscles (all p < 0.05), while for the biceps femoris, this effect was found only in the stretching condition (p < 0.05). EMG activity increased in the rectus femoris, vastus lateralis, and vastus medialis for the stretching condition. For the non-stretching condition, activity only increased in the vastus lateralis and medialis. There was no difference in EMG activity for the biceps femoris and iliocostalis in both conditions. Conclusion: Stretching the hamstrings immediately before each set of the back squat can be used to acutely increase biceps femoris thickness without impairing squat performance.
... There is a possible association between muscle damage with the increase in protein synthesis; and although not linear, also with muscle hypertrophy (Damas et al., 2016). A part from muscle damage and tension, metabolic stress is an important mediator of hypertrophic adaptations (Schoenfeld, 2013;Goto et al., 2017). It is speculated that once a certain level of mechanical tension is generated, metabolic stress may assume a determinant role in the optimization of hypertrophic responses (Schoenfeld, 2013). ...
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Background The pre-exhaustion (PreEx) method is used as a resistance training (RT) method to increase muscle mass, yet the chronic effects of this method are poorly understood.Objective Although readily prescribed as a RT method for promotion of muscle hypertrophy, few researches give light to gains made after chronic PreEx RT. Therefore, we compared the effects of traditional versus PreEx RT programs on muscle strength, body composition, and muscular hypertrophy in adult males.Methods Untrained subjects (age: 31.37 ± 6.83 years; height: 175.29 ± 5.52 cm; body mass: 82.04 ± 13.61 kg; 1RM leg press: 339.86 ± 61.17 kg; 1RM leg extension: 121.71 ± 11.93 kg) were submitted to 9 weeks of RT with weekly sessions. Traditional (TRT) group (n = 12) performed three sets at 45° of leg press exercise at 75% of 1RM, PreEx group (n = 12) completed a set to failure on a leg extension machine prior to the leg press, and the control (CON) group (n = 7) did not train. Maximum strength, muscle thickness, and body composition were analyzed.ResultsPreEx group increased in maximal strength on leg press (16 ± 8%) and leg extension (17 ± 11%), while the TRT group improved by 15 ± 9 and 11 ± 4%, respectively. The thickness of the quadriceps muscles increased for both intervention groups. Specifically, the post-training thickness of the vastus lateralis was significantly higher for PreEx (55%) compared to the CON group. The TRT group presented a greater loss of total and thigh fat mass when compared with the PreEx method. These results were found in the presence of a lower training load for the PreEx group.Conclusion The PreEx training can decrease the total training volume while maintaining results in strength and hypertrophy when comparing to TRT. However, TRT may be optimal if the goal is to decrease fat mass.
... For example, some individuals perform the squat with a more hipdominant movement pattern, which in turn tends to reduce excursion at the knee joint. There is some evidence that training through a full ROM elicits a greater hypertrophic response compared to a partial ROM [63,67,68], although these findings are not universal [69]. The extent to which this variable may affect set-volume ratios is undetermined and warrants further investigation. ...
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Resistance training volume, determined by the number of sets performed (set-volume) is considered one of the key variables in promoting muscle hypertrophy. To better guide resistance exercise prescription for weekly per-muscle training volume, the purpose of this paper is to provide evidence-based considerations for set-volume ratios between multi-joint (MJ) and single-joint (SJ) exercises so that practitioners can better manage prescription of training volume in program design. We analyzed this topic from three primary areas of focus: (1) biomechanical and physiological factors; (2) acute research; and (3) longitudinal research. From a biomechanical and physiological standpoint, when considering force production of different muscle groups, the moment arm of a given muscle, “motor abundance”, the link between biomechanics and exercise-induced fatigue, as well as the amount of time in voluntary muscle activation, a logical rationale can be made for SJ exercises producing greater hypertrophy of the limb muscles than MJ exercises (at least from specific exercises and under certain conditions). This would mean that sets for a MJ exercise should be counted fractionally for select muscles compared to an SJ exercise (i.e., less than a 1:1 ratio) when prescribing set-volumes for given muscles. When considering results from acute studies that measured muscle activation during the performance of SJ and MJ exercises, it seems that MJ exercises are not sufficient to maximize muscle activation of specific muscles. For example, during performance of the leg press and squat, muscle activation of the hamstrings is markedly lower than that of the quadriceps. These results suggest that a 1:1 ratio cannot be assumed. Current longitudinal research comparing the effects of training with MJ vs. SJ or MJ + SJ exercises is limited to the elbow flexors and the evidence is somewhat conflicting. Until more research is conducted to derive stronger conclusions on the topic, we propose the best advice would be to view set-volume prescription on a 1:1 basis, and then use logical rationale and personal expertise to make determinations on program design. Future research should focus on investigating longitudinal hypertrophic changes between MJ and SJ in a variety of populations, particularly resistance-trained individuals, while using site-specific measures of muscle growth to more systematically and precisely compute effective individualized set-volumes.
... Lo mismo ha sido demostrado con el ejercicio de sentadilla (Bloomquist et al., 2013). Sin embargo, otras investigaciones como la de M. Goto et al. (2018), esta vez utilizando el ejercicio de extensión de codo en tendido supino con sujetos entrenados, vieron un mayor aumento de la sección transversal del tríceps con la utilización de rangos de movimiento parciales (48 vs 28 %). Los aumentos de área de sección transversal del grupo que entrenó con rangos de movimiento parciales son mayores a los que se suelen encontrar en otros estudios, mientras que los resultados conseguidos por la utilización de rangos de movimiento completo están dentro de los resultados esperables . ...
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Resistance exercise range of motion (ROM) influences muscular adaptations. However, there are no consistent practical guidelines about the optimal ROM for maximizing muscle hypertrophy. The objective of the present paper was to systematically review the literature for studies that compared the effects of full ROM (fROM) and partial ROM (pROM) on muscle hypertrophy. PubMed/MEDLINE, Scopus, and Web of Science databases were searched to identify articles from the earliest record up to and including April 2022. We calculated the effect size (ES) scores of the variables of interest. Eleven studies were included in the review. fROM and pROM performed in the initial part of the ROM elicited greater muscle hypertrophy of the rectus femoris, vastus lateralis, biceps brachii and brachialis distal sites (between-groups ES: 0.20–0.90) than pROM performed in the final part of the ROM. fROM elicited greater muscle growth on the gluteus maximus and adductors than pROM in the final part of the ROM (between-groups ES: 0.24–0.25). Initial pROM produced more favorable proximal rectus femoris hypertrophy than fROM (between-group ES: 0.35–0.38). pROM in the middle part of the ROM elicited greater triceps brachii hypertrophy than fROM (between-groups ES: 1.21). In conclusion, evidence suggests that when training at a longer muscle length—through either a pROM or fROM—some muscles, such as the quadriceps femoris, biceps brachii and triceps brachii tend to experience optimal growth. Thus, the use pROM in the initial part of the excursion in combination with fROM training should be considered when prescribing hypertrophy-oriented resistance training programs.
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The present study compared two unilateral arm curl resistance exercise protocols with a different starting and finishing elbow joint angle in the same ROM for changes in elbow flexors strength and muscle thickness of the trained and non-trained arms. Thirty-two non-resistance trained young adults were randomly assigned to one of the three groups: extended joint training (0°-50°; EXT, n=12); flexed joint training (80°-130°; FLE, n=12); and non-training control (n=8). The exercise training was performed by the dominant arms twice a week for 5 weeks with gradual increases in the training volume over 10 training sessions, and the non-dominant (non-trained) arms were investigated for the cross-education effect. Maximal voluntary contraction torque of isometric (MVC-ISO), concentric (MVC-CON), and eccentric contractions (MVC-ECC), and thickness (MT) of biceps brachii and brachialis of the trained and non-trained arms were assessed at baseline and 4-8 days after the last training session. The control group did not show significant changes in any variables. Significant (P<0.05) increases in MVC-ISO torque (16.2±12.6%), MVC-CON torque (21.1±24.4%), and MVC-ECC torque (19.6±17.5%) of the trained arm were observed for the EXT group only. The magnitude of the increase in MT of the trained arm was greater (P<0.05) for EXT (8.9±3.9%) than FLE (3.4±2.7%). The cross-education effect was evident for MVC-ISO (15.9±14.8%) and MVC-CON (16.7±20.0%) torque of the EXT group only. These results suggest that resistance training at the extended elbow joint induces greater muscle adaptations and cross-education effects than that at flexed elbow joint.
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Influence of different load exercise to muscle activity during subsequent exercise with 75% of one repetition maximum (RM) load among trained and untrained individuals was verified. Resistance-trained men who were involved in resistance training (n = 16) and healthy young men who did not exercise regularly (n = 16) were recruited for this study. Each subject performed bench pressing with a narrow grip exercise using two different training set methods, the drop-set (DS) (3 sets × 2-10 repetitions with 95-75% of 1RM) and the reverse drop-set (RDS) (3 sets × 3-10 repetitions with 55-75% of 1RM). The mean concentric contraction power, root mean square (RMS) of electromyogra-phy (EMG), area under the oxygenated hemoglobin (Oxy-Hb) curve, and time constant for muscle oxygen consumption (TcVO 2mus) values of the triceps brachii were measured during and after the DS and RDS. The trained group demonstrated significantly higher mean muscle power (242.9 ± 39.6 W vs. 215.8 ± 31.7 W), RMS of EMG (86.4 ± 10.4 % vs. 68.3 ± 9.6 %), and area under the Oxy-Hb curve (38.6 ± 7.4 %・sec vs. 29.3 ± 5.8 %・sec) values during the DS than during the RDS (p < 0.05). However, in the untrained group none of the parameters differed significantly for both the DS and RDS. Furthermore , a negative correlation was detected between the area under the Oxy-Hb curve and muscle thickness (r =-0.51, p < 0.01). Long-term effects of DS on muscle strengthening and hypertrophy will be explored in further research.
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Load and range of motion (ROM) applied in resistance training (RT) affect the muscle damage magnitude and the recovery time-course. Since exercises performed with partial ROM allow a higher load compared to those with full ROM, this study investigated the acute effect of a traditional RT exercise using full ROM or partial ROM on muscle damage markers. Fourteen healthy men performed four sets of 10 concentric-eccentric repetitions of unilateral elbow flexion at the Scott bench. Arms were randomly assigned to partial ROM (50° to 100°) and full ROM (0° to 130°) conditions, and load was determined as 80% of one repetition maximum in full and partial ROM tests. Muscle damage markers were assessed pre-exercise, and immediately, 24h, 48h and 72h after exercise. Primary outcomes were peak torque, muscle soreness during palpation and elbow extension, arm circumference, and joint ROM. The load lifted in partial ROM condition (1RM=19.1±3.0kg) was 40±18% higher compared to full ROM (1RM=13.7±2.2kg). 72h after exercise, the full ROM condition led to significant higher soreness sensation during elbow extension (1.3-4.1cm vs. 1.0-1.9cm) and smaller ROM values (97.5-106.1° vs. 103.6-115.7°). Peak torque, soreness from palpation and arm circumference were statistically similar between conditions, although mean values in all time points of these outcomes have suggested a more expressive muscle damage for the full ROM condition. In conclusion, elbow flexion exercise with full ROM seems to induce greater muscle damage than partial ROM exercises, even though higher absolute load was achieved with partial ROM.
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Resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, however, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower-body resistance exercise protocol. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV (P = 0.01-0.02), whereas the lactate response was significantly higher following HV compared to HI (P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI (P = 0.0001-0.04). No significant differences between protocols were observed for the IGF-1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater (P = 0.03) phosphorylation of IGF-1 receptor at 1H following HV compared to HI. Phosphorylation status of all other signaling proteins including mTOR, p70S6k, and RPS6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.
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The impact of using different resistance training (RT) kinematics, which therefore alters RT mechanics, and their subsequent effect on adaptations remain largely unreported. The aim of this study was to identify differences to training at a longer (LR) compared with a shorter (SR) range of motion, as well as the time-course of any changes during detraining. Recreationally active participants in LR (aged 19 ± 2.6 years; n=8) and SR (aged 19 ± 3.4 years; n=8) groups undertook 8 weeks of RT and 4 weeks detraining. Muscle size, architecture, subcutaneous fat and strength were measured at weeks 0, 8, 10 and 12 (repeated measures). A control group (aged 23 ± 2.4 years; n=10) was also monitored during this period. Significant (p>0.05) post-training differences existed in strength (on average 4±2% vs. 18±2%), distal anatomical cross-sectional area (59±15% vs. 16±10%), fascicle length (23±5% vs. 10±2%) and subcutaneous fat (22±8% vs. 5±2%), with LR exhibiting greater adaptations than SR. Detraining resulted in significant (p>0.05) deteriorations in all muscle parameters measured in both groups, with the SR group experiencing a more rapid relative loss of post-exercise increases in strength than LR (p>0.05). Greater morphological and architectural RT adaptations in LR (owing to higher mechanical stress) result in a more significant increase in strength compared to SR. The practical implications for this body of work follow that LR should be observed in resistance training where increased muscle strength and size are the objective, since we demonstrate here that ROM should not be compromised for greater external loading.
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Resistance training is widely recommended to prevent sarcopenia and osteoporosis. However, the effects of upper and lower limb resistance training on arterial stiffness are unclear. The present study investigates the effects of upper and lower limbs resistance training on arterial stiffness. Thirty young healthy subjects (male 19, female 11, aged 20.1 +/- 0.4 years, mean +/- SD) were randomly assigned to upper limb RT group (upper limb group, n = 10, male 7, female 3), lower limb RT group (lower limb group, n = 10, male 7, female 3) and sedentary groups (n = 10, male 6, female 4). The upper and lower limb groups performed RT at 80% of one repetition maximum twice each week for 10 weeks. Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV). In addition, we measured plasma norepinephrine (NE) concentration. baPWV after training in the upper limb group had significantly increased from baseline (P < 0.05). In addition, plasma NE concentration after training in the upper limb group had significantly increased from baseline (P < 0.05). No such changes were observed in the lower limb and sedentary groups. Moreover, a significant positive correlation between baPWV and plasma NE concentration in upper limb group was observed (P < 0.05). In contrast, no significant correlation between baPWV and plasma NE concentration in lower limb and sedentary groups was observed. These findings suggested that upper limbs resistance training increases plasma NE concentration and promotes the increase of arterial stiffness.
Article
A simple muscle tissue spectrophotometer is adapted to measure the recovery time (TR) for hemoglobin/myoglobin (Hb/Mb) desaturation in the capillary bed of exercising muscle, termed a deoxygenation meter. The use of the instrument for measuring the extent of deoxygenation is presented, but the use of TR avoids difficulties of quantifying Hb/Mb saturation changes. The TR reflects the balance of oxygen delivery and oxygen demand in the localized muscles of the quadriceps following work near maximum voluntary contraction (MVC) in elite male and female rowers (a total of 22) on two occasions, 1 yr apart. TR ranged from 10 to 80 s and was interpreted as a measure of the time for repayment of oxygen and energy deficits accumulated during intense exercise by tissue respiration under ADP control. The Hb/Mb resaturation times provide a noninvasive localized indication of the degree of O2 delivery stress as evoked by rowing ergometry and may provide directions for localized muscle power output improvement for particular individuals in rowing competitions.
Article
Motor unit activity was investigated in the biceps brachii of twelve men during concentric (CC) and eccentric (EC) contractions by means of computer aided intramuscular spike amplitude-frequency (ISAF) histograms and surface EMG frequency power spectral analyses. Simultaneous recordings of the intramuscular and surface EMG signals were made during both types of contractions with the elbow joint angle varying from 30 to 150 degrees in reference to a fully extended position. Results demonstrated that r.m.s. amplitude and mean power frequency of the surface EMG were significantly higher during CC, particularly at shorter muscle length; e.g., 259 vs. 131 microV (p less than 0.01) and 102 vs. 91 Hz (p less than 0.05). The intramuscular spike recordings made at 45, 90 and 135 degrees showed greater motor unit (MU) activities during CC along with the presence of MUs with relatively large spike amplitude. The pooled data on the ISAF histograms revealed significantly greater mean MU spike amplitude and frequency during CC as compared to EC; e.g., 439 vs. 108 microV and 16.1 vs. 13.0 Hz at 135 degrees, respectively. These data suggest that EC is associated with much less pronounced MU recruitment and rate modulation due to economical tension development which might be a result of better utilization of elastic energy, particularly those inherent in the actin-myosin cross bridges and also a favorable length-tension relationship under the present experimental conditions.
Article
Relationships among isokinetic, isometric and isotonic strength measurements in knee and elbow extension and flexion were examined in 16 young, healthy men. Isokinetic and isometric torque measurements were obtained from modified Cybex II apparatus. Isokinetic torque values were obtained at velocities of 36 degrees/sec, 108 degrees/sec, and 180 degrees/sec. An electrogoniometer was used to monitor joint angle. A device similar to a Noland-Kuckhoff (NK) table was employed to determine maximal isotonic capabilities using a 1 repetition maximum procedure. Correlations among the 3 testing modes at joint angles of peak isometric torque were generally high (mean = 0.78, range = 0.97 to 0.47) for all 4 muscle groups. The amounts of common variance suggested that all 3 strength testing modes were measuring a similar phenomenon which could be termed maximal voluntary strength. Within a particular muscle group correlations decreased as isokinetic velocities and joint angles became more widely separated.
Article
The two purposes of the present study were 1) to determine the oxygen consumption in working skeletal muscle from the oxygenation measured by near-infrared continuous-wave spectroscopy (NIRcws) with the arterial occlusion method during the resting condition, INT(VT), and INT(MAX) and 2) to examine whether the decline rate of oxygenation is related to maximal oxygen uptake. Eight healthy males (aged 19.8 +/- 0.4 yr, height 166.9 +/- 17.4 cm, weight 62.1 +/- 2.5 kg, and maximal oxygen uptake [VO2max] 55.9 +/- 1.9 ml/kg x min(-1)) took part in this study. The oxygenation was measured by NIRcws during the Wingate anaerobic test (WAnT) and two intermittent pedalling exercises of VT (INT(VT)) and maximal (INT(MAX)) work intensity. The decline rates of oxygenation obtained during the resting condition, INT(VT), and INT(MAX) with arterial occlusion were 0.43 +/- 0.05%/sec, 4.94 +/- 0.31%/sec, and 8.16 +/- 0.38%/sec, respectively, and that during the WAnT without arterial occlusion was 8.73 +/- 0.49%/sec. The decline rate of oxygenation during the WAnTwas significantly (p < 0.0001) related to maximal oxygen uptake (VO2max). These findings indicate that O2 is utilized from the early phase, even during a supramaximal pedalling exercise, and that the oxidative metabolic capacity may be a factor contributing to supramaximal exercises. Therefore the arterial occlusion method with NIRcws is suitable for the evaluation of the muscle O2 consumption during exercise noninvasively.
Article
The knowledge of surface electromyography (SEMG) and the number of applications have increased considerably during the past ten years. However, most methodological developments have taken place locally, resulting in different methodologies among the different groups of users.A specific objective of the European concerted action SENIAM (surface EMG for a non-invasive assessment of muscles) was, besides creating more collaboration among the various European groups, to develop recommendations on sensors, sensor placement, signal processing and modeling. This paper will present the process and the results of the development of the recommendations for the SEMG sensors and sensor placement procedures. Execution of the SENIAM sensor tasks, in the period 1996-1999, has been handled in a number of partly parallel and partly sequential activities. A literature scan was carried out on the use of sensors and sensor placement procedures in European laboratories. In total, 144 peer-reviewed papers were scanned on the applied SEMG sensor properties and sensor placement procedures. This showed a large variability of methodology as well as a rather insufficient description. A special workshop provided an overview on the scientific and clinical knowledge of the effects of sensor properties and sensor placement procedures on the SEMG characteristics. Based on the inventory, the results of the topical workshop and generally accepted state-of-the-art knowledge, a first proposal for sensors and sensor placement procedures was defined. Besides containing a general procedure and recommendations for sensor placement, this was worked out in detail for 27 different muscles. This proposal was evaluated in several European laboratories with respect to technical and practical aspects and also sent to all members of the SENIAM club (>100 members) together with a questionnaire to obtain their comments. Based on this evaluation the final recommendations of SENIAM were made and published (SENIAM 8: European recommendations for surface electromyography, 1999), both as a booklet and as a CD-ROM. In this way a common body of knowledge has been created on SEMG sensors and sensor placement properties as well as practical guidelines for the proper use of SEMG.
Article
The mechanisms that underlie the affect of acute program variables on muscle growth and strength development for strength/power athletes have been of great interest. This investigation examined the affects of two different resistance exercise protocols on muscle oxygenation, and the anabolic hormonal response to such exercise. Eleven experienced resistance-trained male athletes performed four sets of the squat exercise using either a low-intensity, high-volume (LI; 15 repetitions at 60% one-repetition maximum [1-RM]) or high-intensity, low-volume (HI; 4 repetitions at 90% 1-RM) load. Venous blood samples were obtained before (Pre), immediate (IP), 20- (20P), and 40-min (40P) postexercise. Continuous-wave near-infrared spectroscopy was used to measure oxygen desaturation during exercise. No differences in muscle deoxygenation were seen between LI and HI. However, time-dependent postexercise reoxygenation was significantly different between the two exercise sessions (35.3 +/- 17.4 s vs 24.5 +/- 14.3 s in LI and HI, respectively). Testosterone and growth hormone (GH) concentrations were significantly elevated from Pre at IP, 20P, and 40P in both LI and HI. GH concentrations were higher (P<0.05) for LI than at HI at 20P and 40P. Muscle oxygen recovery kinetics appeared to be influenced by differences in the intensity and volume of exercise, and delayed reoxygenation appears to affect the GH response to exercise.
Article
The effect of training with a combination of different loads (multiple-load training) on the force-velocity and force-power relationships was examined with training programs that included maximal isometric contraction (Fmax) and concentric contraction of the elbow flexor muscles. Twenty-one male college students were placed into 3 equal training groups (G(30 + 60), G(30 + 100), and G(30 + 60 + 100)) and performed multiple-load training 3 days per week for 8 weeks. The training load was a set fraction of the maximal isometric strength (% Fmax). The G(30 + 60) group performed 6 repetitions of elbow flexion at 30 and 60% Fmax. The G(30 + 100) group performed 6 repetitions at 30% Fmax and six 5-second Fmax loads. The G(30 + 60 + 100) group performed 4 repetitions at 30 and 60% Fmax and four 5-second Fmax loads. After training, Fmax and maximal velocity significantly increased (p < 0.05) in all 3 training groups. The increases in maximal power were significantly (p < 0.05) different between the G(30 + 60 + 100) group (52.9%) and the G(30 + 100) group (24.2%). These results suggest that multiple-load training programs with 4-6 repetitions are effective for improving muscle power and velocity of the elbow flexors.
Article
Some previous studies have shown that resistance exercise training with venous occlusion causes an enhanced hypertrophy in human muscles. To investigate the effects of blood flow on muscular size at either cellular or subcellular level, we developed an animal model in which several veins from hindlimb muscles of the rat are surgically crush-occluded. Twenty-four male Wister rats were randomly assigned into either a group for sham operation (sham group) or a group for venous occlusion (experimental group; N = 12 for each group). Fourteen days after the operation, plantaris, soleus, gastrocnemius, extensor digitorum longus, and tibialis anterior muscles were dissected from hindlimbs and subjected to morphological and biochemical analyses. Fourteen days after the operation, the muscles expect for soleus showed similar increases in wet weight/body weight (by 7-12%) as compared with the sham-operated group (P < 0.05). Further analyses on the plantaris muscle showed increases in muscle dry weight/ body weight (by 10%) and the concentrations of myofibrillar protein (by 23%), glycogen (by 93%) and lactate (by 23%) after the operation (P < 0.05). Mean fiber cross-sectional area was larger by 34% in the experimental group than in the sham-operated group (P < 0.01). The content of HSP-72 increased, whereas that of myostatin protein decreased (P < 0.01). The expression of nitric oxide synthase-1 (NOS-1) mRNA increased (P < 0.01), whereas that of IGF-1 mRNA showed no significant change (P = 0.36). Although the muscle nitric oxide (NO) concentration tended to increase, but the change was not significant (P = 0.10). Changes in muscle blood flow may affect the muscular size through actions of HSP-72, myostatin, and NOS-1.
Article
We investigated the acute and long-term effects of low-intensity resistance exercise (knee extension) with slow movement and tonic force generation on muscular size and strength. This type of exercise was expected to enhance the intramuscular hypoxic environment that might be a factor for muscular hypertrophy. Twenty-four healthy young men without experience of regular exercise training were assigned into three groups (n = 8 for each) and performed the following resistance exercise regimens: low-intensity [ approximately 50% of one-repetition maximum (1RM)] with slow movement and tonic force generation (3 s for eccentric and concentric actions, 1-s pause, and no relaxing phase; LST); high-intensity ( approximately 80% 1RM) with normal speed (1 s for concentric and eccentric actions, 1 s for relaxing; HN); low-intensity with normal speed (same intensity as for LST and same speed as for HN; LN). In LST and HN, the mean repetition maximum was 8RM. In LN, both intensity and amount of work were matched with those for LST. Each exercise session consisting of three sets was performed three times a week for 12 wk. In LST and HN, exercise training caused significant (P < 0.05) increases in cross-sectional area determined with MRI and isometric strength (maximal voluntary contraction) of the knee extensors, whereas no significant changes were seen in LN. Electromyographic and near-infrared spectroscopic analyses showed that one bout of LST causes sustained muscular activity and the largest muscle deoxygenation among the three types of exercise. The results suggest that intramuscular oxygen environment is important for exercise-induced muscular hypertrophy.
Article
The present study aimed i) to establish an index of muscle cross-sectional area (CSA) based on muscle thickness and circumference through a comparison with muscle CSA determined by magnetic resonance imaging (MRI), and ii) to examine the relationships between muscle strength and the index determined at rest and during the maximal isometric contraction. The muscle CSA of elbow flexors at 60% of the upper arm length (CSA60) and the maximal CSA of elbow flexors (CSAmax) were measured using MRI in 26 men and 8 women. The muscle thickness (MT) of elbow flexors and the circumference (C) of upper arm at 60% of the upper arm length were measured using ultrasonography and anthropometry, respectively, in 29 men and 9 women. The measurements of MT and C were performed in the resting (MT(r) and C(r)) and contracted condition (MT(m) and C(m)), where the subjects performed maximal voluntary contraction (MVC) of isometric elbow joint flexion. The torque developed during MVC was converted into the muscle force (F) of elbow flexors. The MT(r) x C(r) was significantly correlated both with CSA60 and CSAmax (P < 0.001). The F was significantly correlated with MT(m) x C(m) (r = 0.847, P < 0.001) and MT(r) x C(r) (r = 0.839, P < 0.001). However, stepwise multiple regression analysis selected only MT(m) x C(m) as a significant contributor for estimating F. The present study indicates that MT x C reflects muscle CSA, and can be an index for assessing muscle CSA. In addition, the findings obtained here showed a possibility that MT x C during MVC is more closely related to F than that at rest.
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