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Training for Strength and Hypertrophy: An Evidence-based Approach
Abstract
Resistance exercise training (RET)-induced increases in voluntary 1RM strength are greater with higher loads and training by replicating (or close) the strength test. In contrast, RET-induced muscular hypertrophy is primarily mediated by intensity of effort, which is achieved by performing RET to volitional fatigue and with an internal focus on contracting a muscle throughout the exercise range of motion. In addition, RET-induced muscular hypertrophy is augmented by increasing training volume, but with diminishing returns. Other training variables such as volume-load, inter-set rest, and time under tension have negligible effects on RET-induced changes in muscle size or strength. We conclude that an uncomplicated, evidence-based approach to optimizing RET-induced changes in muscle size and strength follows the FITT principle: frequency, intensity (effort), type, and time.
... The athlete was risk stratified prio Exercise with BFR was first implemented with light, elastic band resistance or active range of motion exercise with the goal of building to 20-30 min of total occlusion time per exposure (i.e., 4-6 sets collecting 3-5 min of occlusion per set) (Table 1) [28,83]. From weeks 5-7 after ACLR, bodyweight and progressive resistance exercise was permitted/tolerated; sets to volitional fatigue were then utilized to reflect best evidence for hypertrophy-based resistance training [84]. The set volume for the quadriceps muscle(s) progressed from 8 sets/week (postoperative weeks 2-4) to 12+ sets/week (postoperative weeks 5+) of OKC+CKC exercise [84]. ...
... From weeks 5-7 after ACLR, bodyweight and progressive resistance exercise was permitted/tolerated; sets to volitional fatigue were then utilized to reflect best evidence for hypertrophy-based resistance training [84]. The set volume for the quadriceps muscle(s) progressed from 8 sets/week (postoperative weeks 2-4) to 12+ sets/week (postoperative weeks 5+) of OKC+CKC exercise [84]. ...
... Exercise with BFR was first implemented with light, elastic band resistance or active range of motion exercise with the goal of building to 20-30 min of total occlusion time per exposure (i.e., 4-6 sets collecting 3-5 min of occlusion per set) (Table 1) [28,83]. From weeks 5-7 after ACLR, bodyweight and progressive resistance exercise was permitted/tolerated; sets to volitional fatigue were then utilized to reflect best evidence for hypertrophy-based resistance training [84]. The set volume for the quadriceps muscle(s) progressed from 8 sets/week (postoperative weeks 2-4) to 12+ sets/week (postoperative weeks 5+) of OKC+CKC exercise [84]. ...
Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.
... The proper manipulation of exercise program variables and the knowledge of their underlying scientific bases, are key for optimizing the results from resistance training interventions (Morton, Colenso-Semple, & Phillips, 2019). Cadence, rest intervals, intensity, volume or frequency are variables that have been evaluated in isolation, even grouping several of them in different protocols (Vargas et al., 2019). ...
... Cadence, rest intervals, intensity, volume or frequency are variables that have been evaluated in isolation, even grouping several of them in different protocols (Vargas et al., 2019). Attentional focus is another relevant program variable to take into account when seeking to maximize muscular adap-tations (Morton et al., 2019). There are two basic categories of attentional focus: internal focus (IF) and external focus (EF). ...
... For this reason, one might think that higher rates of exertion may benefit the hypertrophic stimulus. However, when total work is matched, RPE is related to intensity (30% -60% -90% RM) with training volume being the primary programming variable for generating hypertrophy Morton et al., 2019. (Duncan et al., 2006Lagally, Robertson, Gallagher, Gearhart, & Goss, 2002) Consequently, although there was no difference between the groups in [bLa-], the effect sizes favoured IF. ...
The aim of this study was to investigate the effect of internal focus (IF) and external focus (EF) on lactate production and the perception of perceived exertion in the squat in strength trained-men. Methods: Thirteen men with experience in strength training (age =22.61 ± 1.19 years; height = 180 ± 6.55 cm; body mass = 79.38 ± 5.57 kg; BMI = 24.56 ± 2.11 kg·m-2; Squat = 129 ± 20 kg) performed two sessions, separated by one week, comprising 3 sets of 10 repetitions of the back squat with one minute of rest between sets. During the IF protocol participants were instructed to focus on tightening the quads during all repetitions, while participants in the EF were instructed to focus on lifting the barbell. Blood lactate samples were collected before and at immediately after each of the 3 sets, as well as 15 minutes after the last set. Additionally, the rating of perceived exertion (RPE) was evaluated using the OMNI-RES scale immediately after the completion of each session. Results: Significant increases were found in the IF protocol at the end of each of the 3 sets, with significant effect sizes (1ª set, P= .000, d= 2.66; 2ª set, P= .000; d= 3.14; 3ª set, P= .000, d= 3.50), as in the EF protocol (1ª set, P= .001, d= 2.24; 2ª set, P= .000, d= 3.35; 3ª set, P= .000; d= 3.67). However, there were no significant inter-group differences between pre and any set (1ª set, P=0.951, d=0.03; 2ª set, P=0.239, d=0.47; 3ª set, P=0.435, d=0.31, respectively). Additionally, the perceptions on the RPE scale were higher in the FI (P= 0.032; d = 0.47). Conclusions: Findings suggest that the application of IF may indirectly contribute to muscle hypertrophy in multi-joint lower limb exercises, due to the increase in RPE values and the existing correlation with lactate production. Keywords: Mind-muscle, muscle hypertrophy, internal focus, mind-muscle connection, resistance training
... letter on our paper highlights a minor semantic dispute rather than a fundamental difference of opinion. Nonetheless, we provide here a more nuanced evidence-based explanation than was provided in our paper [1]. ...
... Programming manipulation over time should, in our opinion, be individualized to the athlete (or non-athlete) and one variable that could be manipulated is load, but there is a myriad of others that all, via a higher intensity of effort, mediate hypertrophy. We hope our clarification serves to highlight the evidencebased science and prescriptive advice we offered in our review [1]. ...
... Juneau and Tafur's letter on our paper highlights a minor semantic dispute rather than a fundamental difference of opinion. Nonetheless, we provide here a more nuanced evidence-based explanation than was provided in our paper [1]. ...
... The effects of manipulating resistance training (RT) variables on muscle hypertrophy response has been an ongoing focus of investigation [1][2][3]. Among the RT variables, range of motion (ROM) was generally overlooked in past studies targeting training prescription recommendations [3,4]. ...
... The effects of manipulating resistance training (RT) variables on muscle hypertrophy response has been an ongoing focus of investigation [1][2][3]. Among the RT variables, range of motion (ROM) was generally overlooked in past studies targeting training prescription recommendations [3,4]. However, its influence on neuromuscular responses is becoming increasingly recognized as a potential area of research interest [5,6]. ...
Objective:
The effects of ROM manipulation on muscle strength and hypertrophy response remain understudied in long-term interventions. Thus, we compared the changes in strength and regional muscle hypertrophy after training in protocols with different ranges of motion (ROM) in the seated dumbbell preacher curl exercise using a within-participant experimental design.
Design and methods:
Nineteen young women had one arm randomly assigned to train in the initial ROM (INITIALROM: 0°-68°; 0° = extended elbow) while the contralateral arm trained in the final ROM (FINALROM: 68°-135°), three times per week over an eight-week study period. Pre- and post-training assessments included one repetition maximum (1RM) testing in the full ROM (0°-135°), and measurement of biceps brachii cross-sectional area (CSA) at 50% and 70% of humerus length. Paired t-tests were used to compare regional CSA changes between groups, the sum of CSA changes at 50% and 70% (CSAsummed), and the strength response between the training protocols.
Results:
The INITIALROM protocol displayed a greater CSA increase than FINALROM protocol at 70% of biceps length (p = 0.001). Alternatively, we observed similar increases between the protocols for CSA at 50% (p = 0.311) and for CSAsummed (p = 0.111). Moreover, the INITIALROM protocol displayed a greater 1RM increase than FINALROM (p < 0.001).
Conclusions:
We conclude that training in the initial angles of elbow flexion exercise promotes greater distal hypertrophy of the biceps brachii muscle in untrained young women. Moreover, the INITIALROM condition promotes a greater dynamic strength increase when tested at a full ROM compared to the FINALROM.
... 1, 2 Increasing muscle size is one of the main goals of resistance training, and several evidence-based hypertrophy-oriented training guidelines have been established and updated in the past three decades for various training variables such as load/intensity, volume, repetition speed/tempo, and inter-set rest. [3][4][5][6][7] On the other hand, only relatively recently have studies begun to examine the influence of muscle length/joint angle during exercise on muscle hypertrophy. [8][9][10][11][12][13][14][15] Nevertheless, a growing body of evidence suggests that muscle hypertrophy is promoted when resistance training is conducted at long vs. short muscle lengths (see 16 for a recent review), likely attributable, at least in part, to greater metabolic stress 17 and IGF-1 expression 10 associated with exercise at long muscle lengths. ...
... However, resistance training guidelines generally recommend dynamic exercises with a full ROM when possible. 3,5,6 Thus, it is of great practical importance to compare hypertrophic effects of full ROM exercises that place the same target muscle(s) under long vs. short conditions. Based on the characteristics of biarticular muscles that their lengths are influenced by two joints the muscles cross, we recently compared hamstrings muscle hypertrophy induced by seated (hip-flexed: long) vs. prone (hip-extended: short) leg curl training performed with a full ROM. ...
The biarticular triceps brachii long head (TBLong) is lengthened more in the overhead than neutral arm position. We compared triceps brachii hypertrophy after elbow extension training performed in the overhead vs. neutral arm position. Using a cable machine, 21 adults conducted elbow extensions (90−0°) with one arm in the overhead (Overhead-Arm) and the other arm in the neutral (Neutral-Arm) position at 70% one-repetition maximum (1RM), 10 reps/set, 5 sets/session, 2 sessions/week for 12 weeks. Training load was gradually increased (+5% 1RM/session) when the preceding session was completed without repetition failure. 1RM of the assigned condition and MRI-measured muscle volume of the TBLong, monoarticular lateral and medial heads (TBLat+Med), and whole triceps brachii (Whole-TB) were assessed pre- and post-training. Training load and 1RM increased in both arms similarly (+62−71% at post, P = 0.285), while their absolute values/weights were always lower in Overhead-Arm (-34−39%, P < 0.001). Changes in muscle volume in Overhead-Arm compared to Neutral-Arm were 1.5-fold greater for the TBLong (+28.5% vs. +19.6%, Cohen's d = 0.61, P < 0.001), 1.4-fold greater for the TBLat+Med (+14.6% vs. +10.5%, d = 0.39, P = 0.002), and 1.4-fold greater for the Whole-TB (+19.9% vs. +13.9%, d = 0.54, P < 0.001). In conclusion, triceps brachii hypertrophy was substantially greater after elbow extension training performed in the overhead versus neutral arm position, even with lower absolute loads used during the training.
• Highlights
• Growing evidence suggests that resistance training at long muscle lengths promotes muscle hypertrophy, but its practical applications are yet to be explored.
• Triceps brachii muscle hypertrophy was substantially greater after cable elbow extension training performed in the overhead than neutral arm position, particularly in the biarticular triceps brachii long head, even with lower absolute loads lifted (i.e. lower mechanical stress to muscles/joints).
• Cable elbow extension training should be performed in the overhead rather than neutral arm position if one aims to maximise muscle hypertrophy of the triceps brachii or to prevent atrophy of this muscle.
... Manipulation of resistance training variables to maximize muscle strength and hypertrophy has been widely investigated [64][65][66]. While there are some crossover effects, training for muscle strength or hypertrophy requires separate loading schemes to optimise specific training adaptations [65]. ...
... Manipulation of resistance training variables to maximize muscle strength and hypertrophy has been widely investigated [64][65][66]. While there are some crossover effects, training for muscle strength or hypertrophy requires separate loading schemes to optimise specific training adaptations [65]. This is due to increases in strength being preceded by neuromuscular changes that increase the capacity to produce force [67]. ...
There is a wide variance in the magnitude of physiological adaptations after resistance or endurance training. The incidence of “non” or “poor” responders to training has been reported to represent as high as 40% of the project’s sample. However, the incidence of poor responders to training can be ameliorated with manipulation of either the training frequency, intensity, type and duration. Additionally, global non-response to cardio-respiratory fitness training is eliminated when evaluating several health measures beyond just the target variables as at least one or more measure improves. More research is required to determine if altering resistance training variables results in a more favourable response in individuals with an initial poor response to resistance training. Moreover, we recommend abandoning the term “poor” responders, as ultimately the magnitude of change in cardiorespiratory fitness in response to endurance training is similar in “poor” and “high” responders if the training frequency is subsequently increased. Therefore, we propose “stubborn” responders as a more appropriate term. Future research should focus on developing viable physiological and lifestyle screening tests that identify likely stubborn responders to conventional exercise training guidelines before the individual engages with training. Exerkines, DNA damage, metabolomic responses in blood, saliva and breath, gene sequence, gene expression and epigenetics are candidate biomarkers that warrant investigation into their relationship with trainability. Crucially, viable biomarker screening tests should show good construct validity to distinguish between different exercise loads, and possess excellent sensitivity and reliability. Furthermore “red flag” tests of likely poor responders to training should be practical to assess in clinical settings and be affordable and non-invasive. Early identification of stubborn responders would enable optimization of training programs from the onset of training to maintain exercise motivation and optimize the impact on training adaptations and health.
... R esistance training volume, specifically as it pertains to the total number of sets of resistance exercise performed to or near muscular failure (4) for a specific muscle group, has received considerable attention from the scientific community (4,11,26,27) insofar as being posited to be one of the (23,29,27), if not the most (11,26), effective variable for developing muscular hypertrophy. Authors of meta-analyses (20,27) suggested a dose-response relationship between weekly resistance training volume (i.e., the number of sets performed over the training week) and muscle mass accrual in nonresistance-trained individuals; however, experimental data in resistance-trained individuals have shown conflicting results (3,18,24,28). ...
Resistance training volume has been suggested to be one of the most effective variables for developing muscular hypertrophy. Meta-analyses have concluded that there exists a dose-response relationship between weekly resistance training volume (i.e., the number of sets performed over the training week) and muscle mass accrual in nonresistance-trained individuals; however, experimental data in resistance-trained individuals have shown conflicting results. Current literature suggests that the performance of additional sets of resistance exercise within a single training session and training week does not inherently result in greater increases in muscle size compared with groups or conditions that perform lower volumes of resistance training. Notwithstanding these results, it has been suggested that controlling for each individual's previous training volume could improve the precision of the muscle hypertrophic response to resistance training and that failing to do so would disregard the principle of progressive overload. Herein, we explore the evidence for the suggestion that a higher-volume approach to training, in comparison to what an individual has been accustomed to, would improve the precision of the muscle growth response to resistance training and the physiological rationale that may (or may not) underpin this phenomenon.
... [1][2][3][4] Although endogenous biological and physiological factors are pertinent to maximising RT-induced skeletal muscle adaptations, 5 6 RT programming variables can affect RT adaptations. [7][8][9][10][11][12][13] Therefore, a RT prescription (RTx) should be determined appropriately. Each RTx is comprised of a distinct combination of RT variables, and the most-studied RTx variables include the load lifted per repetition, sets per exercise (generally ...
Objective
To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy.
Data sources
MEDLINE, Embase, Emcare, SPORTDiscus, CINAHL, and Web of Science were searched until February 2022.
Eligibility criteria
Randomised trials that included healthy adults, compared at least 2 predefined conditions (non-exercise control (CTRL) and 12 RTx, differentiated by load, sets and/or weekly frequency), and reported muscle strength and/or hypertrophy were included.
Analyses
Systematic review and Bayesian network meta-analysis methodology was used to compare RTxs and CTRL. Surface under the cumulative ranking curve values were used to rank conditions. Confidence was assessed with threshold analysis.
Results
The strength network included 178 studies (n=5097; women=45%). The hypertrophy network included 119 studies (n=3364; women=47%). All RTxs were superior to CTRL for muscle strength and hypertrophy. Higher-load (>80% of single repetition maximum) prescriptions maximised strength gains, and all prescriptions comparably promoted muscle hypertrophy. While the calculated effects of many prescriptions were similar, higher-load, multiset, thrice-weekly training (standardised mean difference (95% credible interval); 1.60 (1.38 to 1.82) vs CTRL) was the highest-ranked RTx for strength, and higher-load, multiset, twice-weekly training (0.66 (0.47 to 0.85) vs CTRL) was the highest-ranked RTx for hypertrophy. Threshold analysis demonstrated these results were extremely robust.
Conclusion
All RTx promoted strength and hypertrophy compared with no exercise. The highest-ranked prescriptions for strength involved higher loads, whereas the highest-ranked prescriptions for hypertrophy included multiple sets.
PROSPERO registration number
CRD42021259663 and CRD42021258902.
... Resistance training is performed to increase strength in consideration of the positive modifications at the neural [1,2] and structural level [3]. All resistance exercises involve muscles primarily carrying out the movement (prime movers) and muscles stabilizing the joint/s around which the movement is realized [4][5][6][7][8][9][10]. ...
The current study analyzed the excitation of biceps brachii, brachioradialis, and anterior deltoid during bilateral biceps curl performed with different handgrips. Ten competitive bodybuilders performed bilateral biceps curl in non-exhaustive 6-rep sets using 8-RM with the forearm in supinated, pronated, and neutral positions. The ascending and descending phase of each variation was separately analyzed using the normalized root mean square collected using surface electromyography. During the ascending phase, (i) biceps brachii excitation was greater with the supinated compared to the pronated [+19(7)%, ES: 2.60] and neutral handgrip [+12(9)%, ES: 1.24], (ii) the brachioradialis showed greater excitation with the supinated compared to the pronated [+5(4)%, ES: 1.01] and neutral handgrip [+6(5)%, ES: 1.10], (iii) the anterior deltoid excitation was greater with the pronated and neutral handgrip compared to the supinated condition [+6(3)% and +9(2)%, ES: 2.07 and 3.18, respectively]. During the descending phase, the anterior deltoid showed greater excitation in the pronated compared to the supinated handgrip [+5(4)%, ES: 1.02]. Changing the handgrips when performing biceps curl induces specific variations in biceps brachii and brachioradialis excitation and requires different anterior deltoid interventions for stabilizing the humeral head. Practitioners should consider including different handgrips in the biceps curl routine to vary the neural and mechanical stimuli.
... It seems that in our population with the use of the BL/UL LP exercise, UL training could be more effective than BL training in improving UL strength. A possible explanation for this might be that UL training offered more training specificity to the UL tests (Morton et al., 2019). Additionally, because of the existence of the bilateral deficit phenomenon (total amount of force produced during BL contraction is less than the sum of two UL contractions), the UL group received greater training loads compared with the BL group and this could be another mechanism for the greater UL strength improvement in the UL training group (Costa et al., 2015;Jones et al., 2012). ...
This study aimed to compare the effects of 5 weeks of unilateral and bilateral leg press training on lower body strength, linear sprinting and vertical jumping performance in adolescent rugby players. Twenty-six male adolescent rugby players (age = 15.3 ± 0.4 years) were assigned to unilateral (n = 9), bilateral (n = 9), and control (n = 8) groups. Training consisted of either the unilateral or the bilateral leg press twice weekly over five weeks, with the control group maintaining habitual training. Lower body unilateral and bilateral strength, vertical jump, and linear sprint performance were assessed before and after training. After 5 weeks of training, both training groups significantly increased the 5-repetition maximum bilateral leg press (unilateral = 8.9%, d = 0.53; bilateral = 10.9%, d = 0.55, p < .01) and the 5-repetition maximum unilateral leg press (unilateral = 20.2%, d = 0.81; bilateral = 12.4%, d = 0.45, p < .01). There was no significant difference between the size of improvement in unilateral and bilateral groups in the 5-repetition maximum bilateral leg press, but the 5-repetition maximum unilateral leg press increased significantly more in the unilateral group (p < .05). No significant training effects were found for vertical jump or linear sprint performance. The results indicated that unilateral leg press training was as effective as bilateral leg press training in improving bilateral strength and more effective in improving unilateral strength in adolescent rugby players. However, strength improvement did not transfer to athletic performance improvements in either group.
... Resistance training is considered a potent stimulus to increase strength [1] through neural [2] and structural adaptations [3]. In this practice, each exercise has a group of prime movers that are primarily stimulated during the movement [4]. ...
The present study investigated the excitation of the biceps brachii and anterior deltoid during bilateral biceps curl performed using the straight vs. EZ barbell and with or without flexing the arms. Ten competitive bodybuilders performed bilateral biceps curl in non-exhaustive 6-rep sets using 8-RM in four variations: using the straight barbell flexing (STflex) or not flexing the arms (STno-flex) or the EZ barbell flexing (EZflex) or not flexing the arms (EZno-flex). The ascending and descending phases were separately analyzed using the normalized root mean square (nRMS) collected using surface electro-myography. For the biceps brachii, during the ascending phase, a greater nRMS was observed in STno-flex vs. EZno-flex (+1.8%, effect size [ES]: 0.74), in STflex vs. STno-flex (+17.7%, ES: 3.93) and in EZflex vs. EZno-flex (+20.3%, ES: 5.87). During the descending phase, a greater nRMS was observed in STflex vs. EZflex (+3.8%, ES: 1.15), in STno-flex vs. STflex (+2.8%, ES: 0.86) and in EZno-flex vs. EZflex (+8.1%, ES: 1.81). The anterior deltoid showed distinct excitation based on the arm flexion/no-flexion. A slight advantage in biceps brachii excitation appears when using the straight vs. EZ barbell. Flexing or not flexing the arms seems to uniquely excite the biceps brachii and anterior deltoid. Practitioners should consider including different bilateral biceps barbell curls in their routine to vary the neural and mechanical stimuli.
... They include working out at least three times a week with adequate volume: more than 15 sets per muscle group per week and each set contains more than 10 repetitions. Besides, the intensity refers to contracting each muscle group throughout the range of motion (Morton et al., 2019). ...
Cosmetic surgery is a thriving industry worldwide and Thailand is one of the market leaders. However, research which has explored issues concerning cosmetic surgery largely focuses on that of females. Moreover, it revolves around surveying clients, either quantitatively or qualitatively, rather than investigating the text which they consume. Even among the studies examining such text, they are predominantly conducted with the text published in offline media and within a Western context.
Therefore, the current study seeks to address such knowledge gaps by concentrating on online texts which male clients possibly consult for cosmetic surgery in Thailand. Since it is required by law that cosmetic surgery be conducted within authorised medical establishments, Thai cosmetic hospitals play a vital role in pursuing particular discursive strategies to communicate with clients. It is those strategies which the present study intends to investigate. To be exact, it intends to answer the following research questions: (1) What discursive strategies are employed by Thai cosmetic hospitals to propagate the ideologies about cosmetic surgery for masculinity enhancement? and (2) How do such strategies operate?
To answer the first question, the present study employs Van Dijk’s conception of the ideological square. It consists of how to: (1) emphasise our good things, (2) de-emphasise our bad things, (3) emphasise their bad things and (4) de-emphasise their good things. This framework is useful in providing a general principle of how hospitals are likely to communicate with clients. However, an additional issue may arise with regard to, for example, in which way hospitals actually emphasise the good things of cosmetic surgery. Such an issue connects with the second research question. Hence, the other framework, Taylor’s six-segment message strategy model, comes into play by functioning as a specific tool to answer it. The model consists of the ego, social, sensory, routine, acute need, and ration message strategies.
Methodologically, the present study utilises a corpus-assisted discourse analysis which amalgamates a quantitative method (the identification of significant keywords and collocations) into a qualitative analysis (the investigation of data extracts containing those significant lexical items). The corpus consists of the English version of webpage content belonging to 20 Thai hospitals with a total number of 73,168 words.
The findings reveal that, firstly, to emphasise the good things of cosmetic surgery, hospitals implement the ego, social, sensory and ration strategies. Secondly, to de-emphasise the bad things of post-operative complications, hospitals employ the ration strategy. Thirdly, to emphasise the bad things of not undergoing cosmetic surgery, hospitals adopt the ego strategy. Fourthly, to de-emphasise the good things of other means which are perceived as a rival to cosmetic surgery, hospitals pursue the ego and ration strategies. Overall, a preponderance of these strategies revolves around the notion of masculinity, which is conceptualised as the ideology concerning how to feel like a man, act like a man and have a body touted as a man.
The current study makes a theoretical and practical contribution. Theoretically, it is among the first which triangulates the discourse and the communication frameworks to analyse gender-related discourse pertaining to cosmetic surgery for masculinity enhancement in the Thai context. Practically, it hopes to raise awareness and promote media literacy among male clients about how cosmetic hospitals manifest and medicalise the ideology of masculinity via their online platforms.
... Exercise training can induce specific muscular adaptations depending on the exercise mode (Hawley, 2009;Hawley et al., 2014;Coffey and Hawley, 2016). For instance, resistance exercise training interventions maximize neuromuscular adaptations, such as muscle hypertrophy and strength (Campos et al., 2002;Mitchell et al., 2013;Bellamy et al., 2014;Nader et al., 2014;Damas et al., 2016;Morton et al., 2019). On the other hand, aerobic exercise training interventions improve aerobic muscle metabolism and cardiorespiratory fitness (e.g., aerobic power) (Maeda et al., 2001;Coffey and Hawley, 2007;Daussin et al., 2007;Sloth et al., 2013;Konopka et al., 2014;Milanovic et al., 2015). ...
Losses in skeletal muscle mass, strength, and metabolic function are harmful in the pathophysiology of serious diseases, including breast cancer. Physical exercise training is an effective non-pharmacological strategy to improve health and quality of life in patients with breast cancer, mainly through positive effects on skeletal muscle mass, strength, and metabolic function. Emerging evidence has also highlighted the potential of exercise-induced crosstalk between skeletal muscle and cancer cells as one of the mechanisms controlling breast cancer progression. This intercellular communication seems to be mediated by a group of skeletal muscle molecules released in the bloodstream known as myokines. Among the myokines, exercise-induced circulating microRNAs (c-miRNAs) are deemed to mediate the antitumoral effects produced by exercise training through the control of key cellular processes, such as proliferation, metabolism, and signal transduction. However, there are still many open questions regarding the molecular basis of the exercise-induced effects on c-miRNA on human breast cancer cells. Here, we present evidence regarding the effect of exercise training on c-miRNA expression in breast cancer, along with the current gaps in the literature and future perspectives.
... Moreover, velocity-based methods may be used to quantitatively monitor volitional fatigue in real-time and standardise the fatigue incurred during a workout [52]. Therefore strength testing and resistance training program will be conducted using velocity-based methods in conjunction with recommended evidence-based training variables targeting muscle hypertrophy [53]. ...
Participation in resistance training improves muscle strength and size, as well as reduced risk of chronic disease and frailty. However, the exercise response to resistance training is highly variable. In part this may be attributed to individual physiological differences. Identification of biomarkers that can distinguish between high and low responders to exercise are therefore of interest. Exhaled volatile organic compounds may provide a non-invasive method of monitoring the physiological response to resistance training. However, the relationship between exhaled organic compounds and the acute response to resistance exercise is not fully understood. Therefore, this research will investigate exhaled volatile organic compounds in acute response to resistance exercise with an aim to discover a common group of compounds that can predict high and low responders to standardised resistance training.
... There were no significant differences between groups in daily intake of carbohydrates, protein, lipids, and kilocalories during the study period (Table 3). With the ingestion of the supplements (35 g/day; 0.5 g·kg −1 ·day −1 ), the daily protein intake of both groups ranged from 1.6 to 2.0 g·kg −1 ·day −1 , which corresponds to an adequate intake to maximize gains in muscle mass in young adults (Morton et al., 2019;Thomas et al., 2016). ...
The purpose of this study was to investigate the effects of supplementation of whey protein (WP) versus leucine-matched collagen peptides (CP) on muscle thickness (MT) and performance after a resistance training (RT) program in young adults. Twenty-two healthy untrained participants were randomly assigned to either a WP (n = 11) or leucine-matched CP (n = 11) group and then submitted to a supervised 10-wk RT program (3 d·wk-1). The groups were supplemented with an equivalent amount of WP (35 g, containing 3.0 g of leucine) and CP (35 g, containing 1.0 g of leucine and 2.0 g of free leucine) during the intervention period (after each workout and in the evening on non-training days). MT of the vastus lateralis and biceps brachii, isokinetic peak torque (PT) and mean power output (MPO) of the elbow flexors, and peak power output (PPO) of the lower body were assessed before and after the RT program. WP group experienced a greater (interaction P < 0.05) increase in the vastus lateralis (effect size, WP: 0.68 vs. CP: 0.38; ∆%, WP: 8.4 ± 2.5 vs. CP: 5.6 ± 2.6%) and biceps brachii MT (effect size, WP: 0.61 vs. CP: 0.35; ∆%, WP: 10.1 ± 3.8 vs. CP: 6.0 ± 3.2%), with a similar increase in muscle performance (PT, MPO, and PPO) between groups (time p < 0.05). Supplementation with WP was superior to leucine content-matched CP supplementation in increasing muscle size, but not strength and power, after a 10-wk RT program in young adults.
... Panton et al. (2004) also reported 2.9% increase in the lower limb fat-free mass after 12 weeks of combined aerobic and resistance training in COPD patients. We speculate that the increases in lower limb fat-free mass could be due to the higher workload produced during eccentric cycling, which induced greater muscle hypertrophy (Morton et al. 2019). Thus, it is possible that hypertrophy after ECC could be mediated by greater activation of the protein synthesis signaling pathways and a decrease of the atrophy-related genes as shown in previous studies in healthy individuals (Valladares-Ide et al. 2019). ...
PurposeThe present study compared the effects of eccentric cycling (ECC) and conventional concentric cycling (CONC) training on muscle function, body composition, functional performance, and quality of life (QOL) of patients with moderate chronic obstructive pulmonary disease (COPD).Methods
Twenty patients (age: 69.6 ± 10.1 years, forced expiratory volume in 1-s: 73.2 ± 11.4% of predicted) were randomly allocated to ECC (n = 10) or CONC (n = 10) group. They performed 12 weeks of ECC or CONC training at similar perceived exertion. The workload, heart rate (HR), blood oxygen saturation (SpO2), and dyspnea were monitored during cycling. Outcomes measures included maximal voluntary isometric contraction (MVC) strength of the knee extensors, rate of force development (RFD), lower limb fat-free (LLFFM) and fat (LLFM) mass, 6-min walking test (6MWT), timed up-and-go test (TUG), stairs ascending (SAWT) and descending walking time (SDWT), and QOL assessed by the Saint George's respiratory questionnaire.ResultsECC produced on average threefold greater (P < 0.001) workload (211.8 ± 106.0 kJ) than CONC (78.1 ± 62.6 kJ) over 34 training sessions. ECC showed 1.5 ± 2.1% greater SpO2, 24.7 ± 4.1% lower HR, and 64.4 ± 29.6% lower dyspnea in average than CONC (P < 0.001). ECC increased LLFFM (4.5 ± 6.2%; P = 0.03), while CONC decreased LLFM (3.3 ± 6.4%; P = 0.04) after training. Both ECC and CONC reduced (P < 0.05) SAWT (− 16.1 ± 9.3% vs − 10.1 ± 14.4%) and SDWT (− 12.2 ± 12.6% vs − 14.4 ± 14.7%), and improved (P < 0.05) QOL (33.4 ± 38.8 vs 26.1 ± 36.6%) similarly, but only ECC improved (P < 0.05) RFD (69–199%), TUG (13.6 ± 13.6%), and 6MWT (25.3 ± 27.7%).Conclusion
These results suggest that ECC training with less cardio-pulmonary demands was more effective in increasing functional performance and muscle mass for COPD patients than CONC training.
... Por su parte, la masa muscular aumentó en los dos grupos (GBM y GSM), sin embargo, sólo el GSM obtuvo cambios significativos. Estudios previos señalan que para incrementar la masa muscular se deben seguir los principios básicos del entrenamiento, especialmente, lo referente a la magnitud de la carga (duración, volumen, intensidad y densidad), además de considerar la ingesta diaria de proteínas 7,13 . Pese a que los resultados de nuestro estudio reportaron una tendencia de mejora para el GBM, no conseguir cambios significativos en dicho grupo, podría estar relacionado con el volumen y densidad constantes aplicados en la intervención, o bien, con la ingesta proteica, la cual, no controlamos. ...
Introduction: Resistance training exercises must be adapted to people’s characteristics and dosed individually to achieve maximum benefits.
Aim: To compare the effects of a resistance training program on body composition and maximum strength in physically active university students, according to their baseline body mass index (BMI).
Material and methods: Twenty-four Physical Education students (15 males and 9 females) completed a supervised resistance training program that lasted eight weeks (16 sessions). The students were previously distributed into a group below the mean BMI group (BMG; n = 11; 7 males and 4 females) and above the mean BMI group (AMG; n = 13; 8 males and 5 females). Body weight, height, BMI, body composition (adipose mass and muscle mass), and maximum upper body strength (bench press and military press), and lower body strength (parallel squat [45°] and deadlift) were measured through a one-repetition maximum (1RM).
Results: Fat mass decreased significantly (p< 0.05) with a small effect size (d< 0.30) in both groups (BMG and AMG). In contrast, muscle mass increased significantly (p= 0.008) only in AMG with a small effect size (d= 0.36). Maximum upper and lower body strength increased significantly (p< 0.05) with a small and moderate effect size (d< 0.80) in the BMG and AMG. Comparisons between the groups revealed no significant differences.
Conclusions: An eight-week resistance training program significantly reduces fat mass and a significant increase in maximal upper and lower body strength in physically active university students, independent of their baseline BMI. However, only AMG achieves a significant increase in muscle mass.
... The effectiveness of RT is associated with the appropriated manipulation of variables related to intensity and volume [6,10,11]. Current evidence suggests that increases in strength are more dependent on the intensity of load, while muscle hypertrophy is related to the RT volume [12][13][14][15][16]. However, the best approach to improve CVD risk factors in older women is still unknown [6,7,17,18]. ...
This study analyzed the effects of the pyramidal resistance training (RT) system with two repetition zones on cardiovascular risk factors in older women (≥ 60 years old). Fifty-nine older women were randomly assigned in three groups: non-exercise control (CON, n = 19), narrow-pyramid system (NPR, n = 20), and wide-pyramid system (WPR, n = 20). Training groups performed eight weeks of RT (eight exercises for the whole-body, 3x/week, non-consecutive days) in which NPR and WPR performed 3 sets of 12/10/8, and 15/10/5 repetitions, respectively. Regional body fat was estimated by dual-energy X-ray absorptiometry. Blood parameters related to glycemic, lipid, and inflammatory profiles were assessed. After the training period, although no difference was observed for the magnitude of the changes between NPR and WPR, significant group by time interactions indicated benefits with RT compared to CON for reducing body fat (mainly android body fat; -7%) and improving glucose, HDL-C, LDL-C and C-reactive protein (P < 0.05). Composite z-score of cardiovascular risk, created by the average of the intervention effects on the outcomes, indicate similar responses between NPR and WPR, differing from CON (P < 0.001). Results indicate that both repetition-zones of the pyramidal RT reduced similarly the cardiovascular risk in older women.
... Strong evidence indicates that low-load resistance training (LL-RE) combined with blood flow restriction (BFR) can elicit comparable muscular adaptations to traditional high-load resistance training [1][2][3][4][5][6]. BFR resistance training (BFR-RE) offers a distinct advantage compared to traditional high-load resistance training (HL-RE) in that it does not require the recommended intensities associated with traditional resistance exercise [7] in order to induce positive neuromuscular adaptations. In fact, BFR-RE incorporates exercise loads corresponding to 20 to 30% of an individual's one-repetition maximum (1-RM), rather than loads exceeding 70% of a person's 1-RM [8,9]. ...
The purpose of the current investigation was to compare the acute perceptual responses during low-load resistance exercise (RE) with clinical blood flow restriction (cBFR-RE) and practical blood flow restriction (pBFR-RE), and during conventional low- (LL-RE) and high-load resistance exercise (HL-RE), to determine if these responses differed between young males and females. Twenty-nine participants (14 males: 23.6±2.7years, 25.3±3.1kg/m² and 15 females: 20.3±1.6years, 23.4±1.9kg/m²) completed the following exercise conditions in a randomized design: 1) cBFR-RE, 2) pBFR-RE, 3) HL-RE, and 4) LL-RE. Low-load conditions consisted of 30-15-15-15 repetitions of two-leg press (LP) and knee extension (KE) exercises with 30% one-repetition maximum (1-RM), and HL-RE consisted of 3 sets of 10 repetitions at 80% 1-RM, all with 60s rest intervals. Ratings of perceived exertion (RPE) and discomfort were assessed before exercise and immediately following each set. RPE was significantly higher in HL-RE compared to all low-load conditions for both exercises after each set (all p<0.05). cBFR-RE resulted in significantly greater RPE than pBFR-RE and LL-RE for both exercises for sets 1-4 for LP and sets 2-3 for KE (all p<0.05). Levels of discomfort were similar between cBFR-RE and HL-RE, which tended to be significantly higher than pBFR-RE and LL-RE (p<0.05). Men reported significantly greater RPE than women following sets 2-4 during KE with cBFR-RE and sets 2 and 3 during KE for HL-RE (all p<0.05). Males also reported significantly greater discomfort than women following sets 2-4 for KE LL-RE (p<0.05). Altogether, these data suggest that pBFR-RE may provide a more favorable BFR condition based on perceptual responses and that perceptual responses may differ between sexes across varying resistance exercise conditions.
... Resistance training is one of the most popular forms of physical exercise and commonly aims to increase muscle strength and mass [1][2][3]. It has been used to promote benefits in a wide range of populations, including healthy young people and chronically ill patients [4][5][6]. ...
The present article aims to compare electromyographic (EMG) activity of the knee extensors during traditional resistance training (TRT) and no load resistance training with or without visual feedback (NL-VF and NL-NF). Sixteen healthy men (age: 25.2 ± 3.6) volunteered to participate in the study. Participants visited the laboratory on three occasions involving: (1) a 10 repetition maximum test (10 RM test), (2) familiarization and (3) performance of knee extensions using TRT, NL-VF and NL-NF in a random order, with 10 min of rest between them. TRT involved the performance of a set to momentary muscle failure using the 10 RM load. NL-NF involved the performance of 10 repetitions with no external load, but with the intention to maximally contract the muscles during the whole set. NL-VF involved the same procedure as NL-NF, but a monitor was positioned in front of the participants to provide visual feedback on the EMG activity. Peak and mean EMG activity were evaluated on the vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Results: there were no significant differences in VM and VL peak EMG activity among different situations. There was a significant difference for peak EMG activity for RF, where TRT resulted in higher values than NL-VF and NL-NF (p < 0.05). Higher values of mean EMG activity were found for VM, VL and RF during TRT in comparison with both NL-VF and NL-NF. Conclusions: resistance training with no external load produced high levels of peak muscle activation, independent of visual feedback, but mean activation was higher during TRT. These results suggest that training with no external load might be used as a strategy for stimulating the knee extensors when there is limited access to specialized equipment. Although the clinical applications of no load resistance training are promising, it is important to perform long-term studies to test if these acute results will reflect in muscle morphological and functional changes.
... • Muscular hypertrophy (growth) is associated with training to muscular fatigue (uncomfortable experience) where one cannot complete that next rep [6]. ...
... [26][27][28][29][30] Strength training of lower intensity, volume, or timeframe might not increase BMD significantly, but can contribute to the maintenance of a certain level. 34 At this point, it is important to emphasize that in case of strength training, a crucial element are the resistance level and the nature of the training itself. 9 To impact muscles and bones sufficiently to prospectively increase BMD, the resistance level of strength training has to be a minimum of 70% of 1-repetition maximum or at least "moderate intensity." ...
Clinical Scenario: Reduced bone mineral density (BMD) is a serious condition in older adults. The mild form, osteopenia, is often a precursor of osteoporosis. Osteoporosis is a pathological condition and a global health problem as it is one of the most common diseases in developed countries. Finding solutions for prevention and therapy should be prioritized. Therefore, the critically appraised topic focuses on strength training as a treatment to counteract a further decline in BMD in older adults. Clinical Question: Is strength training beneficial in increasing BMD in older people with osteopenia or osteoporosis? Summary of Key Findings: Four of the 5 reviewed studies with the highest evidence showed a significant increase in lumbar spine BMD after strength training interventions in comparison with control groups. The fifth study confirmed the maintenance of lumbar spine density due to conducted exercises. Moreover, 3 reviewed studies revealed increasing BMD at the femoral neck after strength training when compared with controls, which appeared significant in 2 of them. Clinical Bottom Line: The findings indicate that strength training has a significant positive influence on BMD in older women (ie, postmenopausal) with osteoporosis or osteopenia. However, it is not recommended to only rely on strength training as the increase of BMD may not appear fast enough to reach the minimal desired values. A combination of strength training and supplements/medication seems most adequate. Generalization of the findings to older men with reduced BMD should be done with caution due to the lack of studies. Strength of Recommendation: There is grade B of recommendation to support the validity of strength training for older women in postmenopausal phase with reduced BMD.
... We suggest future studies may want to consider examining the integration of goal based autoregulatory approaches of strength and conditioning in athletic populations. If hypertrophy is the goal, utilize the wide range of exercise loads (in combination with sufficient volume) which have been demonstrated to induce hypertrophy (20). The chosen load can be based on the athlete's recovery status/mood/preference. ...
The periodization of resistance exercise is often touted as the most effective strategy for optimizing muscle size and strength adaptations. This narrative persists despite a lack of experimental evidence to demonstrate its superiority. In addition, the general adaptation syndrome, which provides the theoretical framework underlying periodization, does not appear to provide a strong physiological rationale that periodization is necessary. Hans Selye conducted a series of rodent studies which used toxic stressors to facilitate the development of the general adaptation syndrome. To our knowledge, normal exercise in humans has never been shown to produce a general adaptation syndrome. We question whether there is any physiological rationale that a periodized training approach would facilitate greater adaptations compared with nonperiodized approaches employing progressive overload. The purpose of this article is to briefly review currently debated topics within strength and conditioning and provide some practical insight regarding the implications these reevaluations of the literature may have for resistance exercise and periodization. In addition, we provide some suggestions for the continued advancement within the field of strength and conditioning.
... Breath restriction post hyperventilation has been shown repeatedly to significantly improve immune response [5] Both uncomfortable doses of heat [4] and cold [9] have distinct restorative properties. Muscular hypertrophy (growth) is associated with training to muscular fatigue (uncomfortable experience) [7]. Novel eccentric contractions from such eccentric effort (like slowly lowering oneself from a pull up) often induces "delayed onset muscle soreness" [3] as part of the recovery/adaptation -also uncomfortable . ...
According to the latest science of human performance, we are wired to thrive and adapt from discomfort. This workshop explores how to leverage that science to improve human wellbeing and to improve sustainability as a side-effect of designing ubiquitous technology to prepare, practice and perform discomfort, for social benefit. We will use Design Jams as a key activity to explore and build up this Uncomfortable Design Methodology. There will be prizes.
... Finally, similar to the major ongoing discussions regarding which variables may be optimal to improve muscular adaptions, such as muscle hypertrophy or strength [376][377][378][379][380][381][382][383][384][385][386][387][388][389][390], the optimal exercise prescription (e.g., exercise variables and training variables) for resistance exercises and/ or resistance training with respect to brain health (including appropriate functional and structural brain changes as well as enhancement of cognitive functions) are largely unknown and have to be elucidated in future studies [105,108,110]. In addition, the interested reader may find further and more detailed information regarding the design of resistance exercise sessions or resistance training in the referenced literature [355,[391][392][393][394]. ...
Background: During the aging process, physical capabilities (e.g., muscular strength) and cognitive functions (e.g., memory) gradually decrease. Regarding cognitive functions, substantial functional (e.g., compensatory brain activity) and structural changes (e.g., shrinking of the hippocampus) in the brain cause this decline. Notably, growing evidence points towards a relationship between cognition and measures of muscular strength and muscle mass. Based on this emerging evidence, resistance exercises and/or resistance training, which contributes to the preservation and augmentation of muscular strength and muscle mass, may trigger beneficial neurobiological processes and could be crucial for healthy aging that includes preservation of the brain and cognition. Compared with the multitude of studies that have investigated the influence of endurance exercises and/or endurance training on cognitive performance and brain structure, considerably less work has focused on the effects of resistance exercises and/or resistance training. While the available evidence regarding resistance exercise-induced changes in cognitive functions is pooled, the underlying neurobiological processes, such as functional and structural brain changes, have yet to be summarized. Hence, the purpose of this systematic review is to provide an overview of resistance exercise-induced functional and/or structural brain changes that are related to cognitive functions.
Methods and results: A systematic literature search was conducted by two independent researchers across six electronic databases; 5957 records were returned, of which 18 were considered relevant and were analyzed.
Short conclusion: Based on our analyses, resistance exercises and resistance training evoked substantial functional brain changes, especially in the frontal lobe, which were accompanied by improvements in executive functions. Furthermore, resistance training led to lower white matter atrophy and smaller white matter lesion volumes. However, based on the relatively small number of studies available, the findings should be interpreted cautiously. Hence, future studies are required to investigate the underlying neurobiological mechanisms and to verify whether the positive findings can be confirmed and transferred to other needy cohorts, such as older adults with dementia, sarcopenia and/or dynapenia.
Keywords: Cognition, Neuroplasticity, Strength exercises, Strength training, Physical activity
There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.
Manipulating resistance training variables is crucial to plan the induced stimuli correctly. When reporting the exercise variables in resistance training protocols, sports scientists and practitioners often refer to the load lifted and the total number of repetitions. The present conceptual review explores all within-exercise variables that may influence the strength and hypertrophic gains, and the changes in muscle architecture. Together with the (1) load and (2) the number of repetitions, (3) performing repetitions to failure or not to failure, (4) the displacement of the load or the range of movement (full or partial), (5) the portion of the partial movement to identify the muscle length at which the exercise is performed, (6) the total time under tension, the duration of each phase and the position of the two isometric phases, (7) whether the concentric, eccentric or concentric-eccentric phase is performed, (8) the use of internal or external focus and (9) the inter-set rest may all have repercussions on the adaptations induced by each resistance exercise. Manipulating one or more variable allows to increase, equalize or decrease the stimuli related to each exercise. Sports scientists and practitioners are invited to list all aforementioned variables for each exercise when reporting resistance training protocols.
Background
Individuals with metabolic syndrome (MetS) are at a greater risk for developing atherosclerotic cardiovascular disease (ASCVD) than those without MetS, due to underlying endothelial dysfunction, dyslipidemia, and insulin resistance. Exercise is an effective primary and secondary prevention strategy for MetS; however, less than 25% of adults meet the minimum stated public recommendations. Barriers often identified are lack of enjoyment and lack of time. High-intensity functional training (HIFT), a time-efficient modality of exercise, has shown some potential to elicit positive affectivity and elicit increased fitness and improved glucose metabolism. However, the effects of HIFT on dyslipidemia and endothelial dysfunction have not been explored nor have the effects been explored in a population with MetS. Additionally, no studies have investigated the minimal dose of HIFT per week to see clinically meaningful changes in cardiometabolic health. The purpose of this study is to (1) determine the dose-response effect of HIFT on blood lipids, insulin resistance, and endothelial function and (2) determine the dose-response effect of HIFT on body composition, fitness, and perceived enjoyment and intention to continue the exercise.
Methods/design
In this randomized, dose-response trial, participants will undergo a 12-week HIFT intervention of either 1 day/week, 2 days/week, or 3 days/week of supervised, progressive exercise. Outcomes assessed at baseline and post-intervention will be multiple cardiometabolic markers, and fitness. Additionally, the participant’s affective response will be measured after the intervention.
Discussion
The findings of this research will provide evidence on the minimal dose of HIFT per week to see clinically meaningful improvements in the risk factors of MetS, as well as whether this modality is likely to mitigate the barriers to exercise. If an effective dose of HIFT per week is determined and if this modality is perceived positively, it may provide exercise specialists and health care providers a tool to prevent and treat MetS.
Trial registration
ClinicalTrials.gov NCT05001126 . August 11, 2021.
Sarcopenia is a generalised skeletal muscle disorder characterised by reduced muscle strength and mass and associated with a range of negative health outcomes. Currently, resistance exercise (RE) is recommended as the first-line treatment for counteracting the deleterious consequences of sarcopenia in older adults. However, whilst there is considerable evidence demonstrating that RE is an effective intervention for improving muscle strength and function in healthy older adults, much less is known about its benefits in older people living with sarcopenia. Furthermore, evidence for its optimal prescription and delivery is very limited and any potential benefits of RE are unlikely to be realised in the absence of an appropriate exercise dose. We provide a summary of the underlying principles of effective RE prescription (specificity, overload and progression) and discuss the main variables (training frequency, exercise selection, exercise intensity, exercise volume and rest periods) that can be manipulated when designing RE programmes. Following this, we propose that an RE programme that consists of two exercise sessions per week and involves a combination of upper- and lower-body exercises performed with a relatively high degree of effort for 1–3 sets of 6–12 repetitions is appropriate as a treatment for sarcopenia. The principles of RE prescription outlined here and the proposed RE programme presented in this paper provide a useful resource for clinicians and exercise practitioners treating older adults with sarcopenia and will also be of value to researchers for standardising approaches to RE interventions in future sarcopenia studies.
Resistance training (RT) is the only non-pharmacological intervention known to consistently improve, and therefore offset age-related declines in, skeletal muscle mass, strength, and power. RT is also associated with various health benefits that are underappreciated compared with the perceived benefits of aerobic-based exercise. For example, RT participation is associated with reduced all-cause and cancer-related mortality and reduced incidence of cardiovascular disease, hypertension, and symptoms of both anxiety and depression. Despite these benefits, participation in RT remains low, likely due to numerous factors including time constraints, a high-perceived difficulty, and limited access to facilities and equipment. Identification of RT strategies that limit barriers to participation may increase engagement in RT and subsequently improve population health outcomes. Across the lifespan, declines in strength and power occur up to eight times faster than the loss of muscle mass, and are more strongly associated with functional impairments and risks of morbidity and mortality. Strategies to maximise healthspan should therefore arguably focus more on improving or maintaining muscle strength and power than on increasing muscle mass per se. Accumulating evidence suggests that minimal doses of RT, characterised by lower session volumes than in traditional RT guidelines, together with either (1) higher training intensities/loads performed at lower frequencies (i.e. low-volume, high-load RT) or (2) lower training intensities/loads performed at higher frequencies and with minimal-to-no equipment (i.e. resistance ‘exercise snacking’), can improve strength and functional ability in younger and older adults. Such minimal-dose approaches to RT have the potential to minimise various barriers to participation, and may have positive implications for the feasibility and scalability of RT. In addition, brief but frequent minimal-dose RT approaches (i.e. resistance ‘exercise snacking’) may provide additional benefits for interrupting sedentary behaviour patterns associated with increased cardiometabolic risk. Compared to traditional approaches, minimal-dose RT may also limit negative affective responses, such as increased discomfort and lowered enjoyment, both of which are associated with higher training volumes and may negatively influence exercise adherence. A number of practical factors, including the selection of exercises that target major muscle groups and challenge both balance and the stabilising musculature, may influence the effectiveness of minimal-dose RT on outcomes such as improved independence and quality-of-life in older adults. This narrative review aims to summarise the evidence for minimal-dose RT as a strategy for preserving muscle strength and functional ability across the lifespan, and to discuss practical models and considerations for the application of minimal-dose RT approaches.
Resistance training (RT) volume is considered a critical variable to induce neuromuscular adaptations (e.g., increased muscle strength). However, emerging findings have allowed us to revisit the role of volume in strength gains.
Objectives: In the present study, we seek to present these emerging findings to discuss the role of RT volume in one-repetition maximum (1RM) strength gains and isometric and isokinetic strength. In addition, we propose alternative ways to test whether or not volume plays a determining role in strength adaptation.
Design & methods: We reviewed the literature on RT volume and muscle strength. In adittion, we examined the RT literature to provide alternative ways to investigate the effect of volume on changes in strength.
Results/conclusions: From the recent findings, we argue that an increase in strength can be achieved through a refined interaction between skill enhancement, regular use of high loads, and neuromuscular fatigue management; these points can be obtained from different RT volumes. From an inquiring point of view, we suggest that future investigations that aim to verify the effects of volume on muscle strength may consider the inclusion of high load sessions (80–100% of 1RM), periodically (e.g., every three or four weeks), in both low and high-volume groups, as well as considering the inclusion of different strength measures (e.g., isokinetic, isometric). We believe that this will help to clarify the nature of the relationship between RT volume and strength adaptations.
Skeletal muscle is the organ of locomotion, its optimal function is critical for athletic performance, and is also important for health due to its contribution to resting metabolic rate and as a site for glucose uptake and storage. Numerous endogenous and exogenous factors influence muscle mass. Much of what is currently known regarding muscle protein turnover is owed to the development and use of stable isotope tracers. Skeletal muscle mass is determined by the meal- and contraction-induced alterations of muscle protein synthesis and muscle protein breakdown. Increased loading as resistance training is the most potent nonpharmacological strategy by which skeletal muscle mass can be increased. Conversely, aging (sarcopenia) and muscle disuse lead to the development of anabolic resistance and contribute to the loss of skeletal muscle mass. Nascent omics-based technologies have significantly improved our understanding surrounding the regulation of skeletal muscle mass at the gene, transcript, and protein levels. Despite significant advances surrounding the mechanistic intricacies that underpin changes in skeletal muscle mass, these processes are complex, and more work is certainly needed. In this article, we provide an overview of the importance of skeletal muscle, describe the influence that resistance training, aging, and disuse exert on muscle protein turnover and the molecular regulatory processes that contribute to changes in muscle protein abundance. © 2021 American Physiological Society. Compr Physiol 11:2249-2278, 2021.
A training plan, or an exercise prescription, is the point where we translate sport and exercise science into practice. As in medicine, good practice requires writing a training plan or prescribing an exercise programme based on the best current scientific evidence. A key issue, however, is that a training plan or exercise prescription is typically a mix of many interacting interventions (e.g. exercises and nutritional recommendations) that additionally change over time due to periodisation or tapering. Thus, it is virtually impossible to base a complex long-term training plan fully on scientific evidence. We, therefore, speak of evidence-informed training plans and exercise prescriptions to highlight that only some of the underlying decisions are made using an evidence-based decision approach. Another challenge is that the adaptation to a given, e.g. endurance or resistance training programme is often highly variable. Until biomarkers for trainability are identified, we must therefore continue to test athletes, clients, or patients, and monitor training variables via a training log to determine whether an individual sufficiently responds to a training intervention or else re-plan. Based on these ideas, we propose a subjective, pragmatic six-step approach that details how to write a training plan or exercise prescription that is partially based on scientific evidence. Finally, we advocate an athlete, client and patient-centered approach whereby an individual’s needs and abilities are the main consideration behind all decision-making. This implies that sometimes the most effective form of training is eschewed if the athlete, client or patient has other wishes.
Using a within-subject design we compared the individual responses between drop-set (DS) vs. traditional resistance training (TRAD) (n=16) and crescent pyramid (CP) vs. TRAD (n=15). Muscle cross-sectional area (CSA), leg press and leg extension 1 repetition maximum (1-RM) were assessed pre and post training. At group level, CSA increased from pre to post (DS: 7.8% vs. TRAD: 7.5%, P=0.02; CP: 7.5% vs. TRAD: 7.8%, P=0.02). All protocols increased the 1-RM from pre to post for leg press (DS: 24.9% vs. TRAD: 26.8%, P < 0.0001; CP: 27.3% vs. TRAD:2 6.3%, P < 0.0001) and leg extension (DS: 17.1% vs. TRAD: 17.3%, P < 0.0001; CP: 17.0% vs. TRAD: 16.6%, P < 0.0001). Individual analysis for CSA demonstrated no differences between protocols in 15 subjects. For leg press 1-RM, 5 subjects responded more to TRAD, 2 to DS and 9 similarly between protocols. In TRAD vs. CP, 4 subjects responded more to CP, 1 to TRAD and 10 similarly between protocols. For leg extension 1-RM 2 subjects responded more to DS, 3 to TRAD and 11 similarly between protocols. Additionally, 2 subjects responded more to CP, 2 to TRAD and 11 similarly between protocols. In conclusion, all protocols induced similar individual responses for CSA. For 1-RM, some subjects experience greater gains for the protocol performed with higher loads, such as CP.
This systematic review and meta-analysis determined resistance training (RT) load effects on various muscle hypertrophy, strength, and neuromuscular performance task [e.g., countermovement jump (CMJ)] outcomes. Relevent studies comparing higher-load [>60% 1-repetition maximum (RM) or <15-RM] and lower-load (≤60% 1-RM or ≥ 15-RM) RT were identified, with 45 studies (from 4713 total) included in the meta-analysis. Higher- and lower-load RT induced similar muscle hypertrophy at the whole-body (lean/fat-free mass; [ES (95% CI) = 0.05 (−0.20 to 0.29), P = 0.70]), whole-muscle [ES = 0.06 (−0.11 to 0.24), P = 0.47], and muscle fibre [ES = 0.29 (−0.09 to 0.66), P = 0.13] levels. Higher-load RT further improved 1-RM [ES = 0.34 (0.15 to 0.52), P = 0.0003] and isometric [ES = 0.41 (0.07 to 0.76), P = 0.02] strength. The superiority of higher-load RT on 1-RM strength was greater in younger [ES = 0.34 (0.12 to 0.55), P = 0.002] versus older [ES = 0.20 (−0.00 to 0.41), P = 0.05] participants. Higher- and lower-load RT therefore induce similar muscle hypertrophy (at multiple physiological levels), while higher-load RT elicits superior 1-RM and isometric strength. The influence of RT loads on neuromuscular task performance is however unclear.
IntroductionUnderstanding the impact of lockdown upon resistance training (RT), and how people adapted their RT behaviours, has implications for strategies to maintain engagement in similar positive health behaviours. Further, doing so will provide a baseline for investigation of the long-term effects of these public health measures upon behaviours and perceptions, and facilitate future follow-up study.Objectives
To determine how the onset of coronavirus (COVID-19), and associated ‘lockdown’, affected RT behaviours, in addition to motivation, perceived effectiveness, enjoyment, and intent to continue, in those who regularly performed RT prior to the pandemic.Methods
We conducted an observational, cross-sectional study using online surveys in multiple languages (English, Danish, French, German, Italian, Portuguese, Slovakian, Swedish, and Japanese) distributed across social media platforms and through authors’ professional and personal networks. Adults (n = 5389; median age = 31 years [interquartile range (IQR) = 25, 38]), previously engaged in RT prior to lockdown (median prior RT experience = 7 years [IQR = 4, 12]) participated. Outcomes were self-reported RT behaviours including: continuation of RT during lockdown, location of RT, purchase of specific equipment for RT, method of training, full-body or split routine, types of training, repetition ranges, exercise number, set volumes (per exercise and muscle group), weekly frequency of training, perception of effort, whether training was planned/recorded, time of day, and training goals. Secondary outcomes included motivation, perceived effectiveness, enjoyment, and intent to continue RT.ResultsA majority of individuals (82.8%) maintained participation in RT during-lockdown. Marginal probabilities from generalised linear models and generalised estimating equations for RT behaviours were largely similar from pre- to during-lockdown. There was reduced probability of training in privately owned gyms (~ 59% to ~ 7%) and increased probability of training at home (~ 18% to ~ 89%); greater probability of training using a full-body routine (~ 38% to ~ 51%); reduced probability of resistance machines (~ 66% to ~ 13%) and free weight use (~ 96% to ~ 81%), and increased probability of bodyweight training (~ 62% to ~ 82%); reduced probability of moderate repetition ranges (~ 62–82% to ~ 55–66%) and greater probability of higher repetition ranges (~ 27% to ~ 49%); and moderate reduction in the perception of effort experienced during-training (r = 0.31). Further, individuals were slightly less likely to plan or record training during lockdown and many changed their training goals. Additionally, perceived effectiveness, enjoyment, and likelihood of continuing current training were all lower during-lockdown.Conclusions
Those engaged in RT prior to lockdown these behaviours with only slight adaptations in both location and types of training performed. However, people employed less effort, had lower motivation, and perceived training as less effective and enjoyable, reporting their likelihood of continuing current training was similar or lower than pre-lockdown. These results have implications for strategies to maintain engagement in positive health behaviours such as RT during-restrictive pandemic-related public health measures.Pre-registrationhttps://osf.io/qcmpf.PreprintThe preprint version of this work is available on SportRχiv: https://osf.io/preprints/sportrxiv/b8s7e/.
Introduction:
Exercise-induced microRNAs (miRNAs) expression has been implicated in the regulation of skeletal muscle plasticity. However, the specificity and acute time course in miRNA expression following divergent exercise modes are unknown. In a randomized cross-over design, we compared the acute expression profile of eight skeletal muscle miRNAs previously reported to be involved in skeletal muscle development, growth and maintenance following a bout of either resistance exercise (RE), high intensity interval exercise (HIIE) and concurrent resistance and high intensity interval exercises (CE).
Methods:
Nine untrained young men (23.9±2.8y, 70.1±14.9kg, 177.2±3.0cm, 41.4±5.2ml·kg-1·min-1) underwent a counter-balanced cross-over design in which they performed bouts of RE (2x10 repetitions maximum 45°Leg Press and Leg Extension exercises), HIEE (12x1 min sprints at VO2peak with 1min rest intervals between sprints) and CE (RE followed by HIIE), separated by one week. Vastus lateralis biopsies were harvested immediately before (Pre), and immediately (0h), 4h and 8h after each exercise bout.
Results:
There were similar increases (main effect of time; P<0.05) in miR-1-3p,-133a-3p,-133b, -181a-3p, and -486 expression at 8h from Pre with all exercise modes. Besides a main effect of time, miR-23a-3p and -206 presented a main effect of condition with lower expression after HIIE compared to RE and CE.
Conclusions:
Select miRNAs (miR-1-3p, -133a-3p,-133b,-23a-3p,-181a-3p,-206,-486) do not exhibit an expression specificity in the acute recovery period following a single bout of either RE, HIIE or CE in skeletal muscle. Our data also indicate that RE has a higher effect on the expression of miR-23a-3p and -206 than HIIE. As upregulation of these miRNAs appears to be confined to the 8h period post-exercise, this may subsequently impact the expression patterns of target mRNAs forming the basis of exercise-induced adaptive responses.
Calculating resistance-training volume in programs focused on muscle hypertrophy is an attempt to quantify the external workload carried out, then to estimate the dose of stimulus imposed on targeted muscles. The volume is usually expressed in some variables that directly affected the total training work, such as the number of sets, repetitions, and volume-load. These variables are used to try to quantify the training work easily, for the subsequent organization and prescription of training programs. One of the main uses of measures of volume quantification is seen in studies in which the purpose is to compare the effects of different training protocols on muscle growth in a volume-equated format. However, it seems that not all measures of volume are always appropriate for equating training protocols. In the current paper, it is discussed what training volume is and the potentials and shortcomings of each one of the most common ways to equate it between groups depending on the independent variable to be compared (e.g., weekly frequency, intensity of load, and advanced techniques).
Background
Anterior cruciate ligament (ACL) reconstruction has a detrimental impact on athletic
performance. Despite rehabilitation guidelines and criterion-based progressions to
ensure safe restoration of fundamental physical capacities and maladaptive movement
strategies, residual deficits in maximal strength, rate of force development (RFD),
power and reactive strength are commonly reported. These combined with associated
compensatory inter and intra-limb strategies increase the risk of re-injury.
Objective
The aim of this article is to examine the relationships between fundamental physical
capacities and biomechanical variables during dynamic movement tasks.
Design
Narrative review
Results
The available data suggests that quadriceps strength and RTD, explain a moderate
portion of the variance in aberrant kinetic and kinematic strategies commonly detected
in ACL reconstructed cohorts at who are during the later stages of rehabilitation and
RTS
Conclusion
The available data suggests that quadriceps strength and rate of torque development,
explain a moderate portion of the variance in aberrant kinetic and kinematic strategies
commonly detected in ACL reconstructed cohorts at who are in the later stages of
rehabilitation and RTS
Verletzungen des Kniegelenkes können zu langen Ausfallzeiten im Sport führen. Dieses Kapitel gibt eine Übersicht über Diagnostik und Therapie von akuten und chronischen Beschwerden am Kniegelenk bei Sportlern. Ausgehend von der aktuellen Evidenz wird der kriterienbasierte Rehabilitationsverlauf für die unterschiedlichen Kniegelenkverletzungen dargestellt. Darüber hinaus wird der Return to Sport-Prozess mit den jeweiligen intrarehabilitativen Assessments anhand biomechanischer und verletzungsspezifischer Überlegungen veranschaulicht.
Background
Residual deficits in athletic performance are common despite rehabilitation guidelines following anterior cruciate ligament reconstruction including criterion-based progressions to protect healing structures, ensure safe restoration of fundamental physical capacities, and guide appropriate return to sports activities. A synthesis of the available literature is warranted to examine the physical readiness of athletic populations in the later stages of rehabilitation in comparison to healthy controls.
Objectives
To determine the level of strength, power, rate of force development, and reactive strength in adult males who are more than six months following anterior cruciate ligament reconstruction.
Methods
A systematic review of the literature was undertaken using the Medline, CINAHL and SPORTDiscus databases and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies including males only and assessed strength, power, rate of force development and reactive strength comparing performance to healthy controls were included. A meta-analysis was also performed to compute standardized mean differences (SMD ± 95% confidence intervals), calculated using Hedge’s g, and examine the effect of ACLR on these fundamental physical capacities.
Results
2023 articles were identified, of which 14 articles with similar level of evidence and methodological quality met the inclusion criteria. The most commonly investigated and impaired physical capacity was quadriceps (g= -0.89, 95% CI [-1.33,-0.44]) and hamstring strength (g= -0.44, 95% CI [-0.78,-0.10]). Only one study investigated rate of force development and none measuring reactive strength met our eligibility criteria.
Conclusions
Pooled data showed moderate evidence indicating large and small negative deficits on knee peak extension and flexion, respectively, in male adults at more than 6 months post anterior cruciate ligament reconstruction. The magnitude of these differences are influenced by graft type and can be mitigated by targeted rehabilitation programs. Insufficient evidence is available in male adults following anterior cruciate ligament reconstruction to examine rate of force development and reactive strength.
Global health organizations have provided recommendations regarding exercise for the general population. Strength training has been included in several position statements due to its multi-systemic benefits. In this narrative review, we examine the available literature, first explaining how specific mechanical loading is converted into positive cellular responses. Secondly, benefits related to specific musculoskeletal tissues are discussed, with practical applications and training programmes clearly outlined for both common musculoskeletal disorders and primary prevention strategies.
To date, there are several knowledge gaps on how to properly prescribe concurrent training to achieve the best dose-response, especially regarding the optimal intensity or volume of the aerobic component. Thus, the objective of this study is to analyze the effects of different aerobic exercise modes and intensities [i.e. aerobic high-intensity interval training (HIIT) versus moderate-intensity continuous aerobic training (MICT) combined with a resistance training (RT) program] on metabolic outcomes in participants with metabolic syndrome (MetS). Thirty-nine men and women (67.0 ± 6.7 years) volunteered to a 12-weeks exercise intervention (3 week–1, 50 min/session) and were randomly assigned to one of three groups: (a) RT plus MICT (RT+MICT) (2 males; 11 females); (b) RT plus HIIT (RT+HIIT) (4 males; 9 females); and (c) control group (CON) – without formal exercise (4 males; 9 females). Intensity was established between 60 and 70% of maximum heart rate (HRmax) in RT+MICT and ranged from 55–65% to 80–90% HRmax in the RT+HIIT group. Dependent outcomes included morphological, metabolic and hemodynamic variables. Both training groups improved waist circumference (RT+MICT: P = 0.019; RT+HIIT: P = 0.003), but not body weight, fat mass or fat-free mass (P ≥ 0.114). RT+HIIT group improved fasting glucose (P = 0.014), low density lipoprotein [LDL (P = 0.022)], insulin (P = 0.034) and homeostatic model assessment (P = 0.028). RT+MICT group reduced triglycerides (P = 0.053). Both exercise interventions did not change high sensitivity C-reactive protein, glycated hemoglobin, high density lipoprotein and total cholesterol, systolic, diastolic or mean arterial blood pressure (P ≥ 0.05). The CON group reduced the LDL (P = 0.031). This trial suggests that short-term exercise mode and intensity may differently impact the metabolic profile of individuals with MetS. Further, our data suggests that both concurrent trainings promote important cardiometabolic gains, particularly in the RT+HIIT. Nonetheless, due to the small-to-moderate effect size and the short-term intervention length, our data suggests that the intervention length also has an important modulating role in these benefits in older adults with MetS. Therefore, more research is needed to confirm our results using longer exercise interventions and larger groups.
A weight (resistance) training program includes training variables, such as exercises, sets, repetitions and training frequency. A training plan describes how the variables should be modified over time. In order to be effective, both training programs and plans should be based on some basic principles, applicable to all trainees. Based on the literature review, the most important and well supported is the principle of progressive overload, which states that the stimulus should be gradually increasing over time. The principle of specificity states that the training adaptations are specific to the stimulus applied, while the principle of variation (and periodization) states that the stimulus should change (within the specificity limits) to remain challenging. Although they are not necessary to increase performance, there is evidence supporting higher improvements. The principle of individuality states that the stimulus should be adjusted based on the individual's needs. Even though overlooked, limited data indicate that it may be more important than specificity and variation. This paper discusses the basic principles, the criticism against them, and how they should be applied when designing resistance training programs. Contribution/Originality: This study documents the principles that a weight training plan should be based on some basic principles, applicable to all trainees. This study contributes in the existing literature by clarifying the confusion and misconceptions on the topic.
Skeletal muscle plays a pivotal role in the maintenance of physical and metabolic health and, critically, mobility. Accordingly, strategies focused on increasing the quality and quantity of skeletal muscle are relevant, and resistance exercise is foundational to the process of functional hypertrophy. Much of our current understanding of skeletal muscle hypertrophy can be attributed to the development and utilization of stable isotopically labeled tracers. We know that resistance exercise and sufficient protein intake act synergistically and provide the most effective stimuli to enhance skeletal muscle mass; however, the molecular intricacies that underpin the tremendous response variability to resistance exercise-induced hypertrophy are complex. The purpose of this review is to discuss recent studies with the aim of shedding light on key regulatory mechanisms that dictate hypertrophic gains in skeletal muscle mass. We also aim to provide a brief up-to-date summary of the recent advances in our understanding of skeletal muscle hypertrophy in response to resistance training in humans.
Objectives:
Little is known regarding the variables or mechanisms mediating cross-education as a result of resistance training. Therefore, the purpose of the present study was to examine the effects of low-load eccentric-only blood flow restriction (Ecc-BFR) and low-load concentric-only BFR (Con-BFR) on indices of cross-education.
Design:
Thirty-six women were randomly assigned to 4-wks of unilateral resistance training with Ecc-BFR (n = 12), Con-BFR (n = 12) or control (no intervention, n = 12) group. Eccentric peak torque, concentric peak torque, maximal voluntary isometric contraction torque, muscle thickness, and muscle activation were assessed from the contralateral, untrained arm.
Results:
Muscle strength (collapsed across mode) increased from 0-wk to 2-wks (4.9%) and 4-wks (13.0%) for Ecc-BFR only. There were increases in muscle activation (collapsed across mode and group) regardless of training modality, but there were no changes in muscle size for any of the conditions.
Conclusions:
The findings of the present study indicated that low-load Ecc-BFR increased muscle strength. The increases in muscle strength as a result of Ecc-BFR were not mode-specific. Thus, low-load Ecc-BFR provides a unique alternative to maintain muscle function in an untrained limb that may have application during limb immobilization and rehabilitation practices.
Purpose
The aim of this study was to compare the effects of resistance training (RT) with an emphasis on either muscular strength-type RT or muscular endurance-type RT on measures of body composition.
Methods
Twenty-five resistance-trained men (age 28.4 ± 6.4 years; body mass 75.9 ± 8.4 kg; height 176.9 ± 7.5 cm) were randomly assigned to either a strength-type RT group that performed three sets of 6–8 repetition maximum (RM) with 3-min rest (n = 10), an endurance-type RT group that performed three sets of 20–25 RM with a 60-s rest interval (n = 10), or a control group (n = 5, CG). All groups completed each set until muscular failure and were supervised to follow a hyperenergetic diet (39 kcal·kg⁻¹·day⁻¹). Body composition changes were measured by dual-energy X-ray absorptiometry.
Results
After 8 weeks, we found significant increases in total body mass (0.9 [0.3–1.5] kg; p < 0.05; ES = < 0.2) and lean body mass (LBM) (1.3 [0.5–2.2] kg; p < 0.05; ES = 0.31) only in the strength-type RT group; however, no significant interactions were noted between groups.
Conclusions
Although only strength-type RT showed statistically significant increases in LBM from baseline, no between-group differences were noted for any body composition outcome. These findings suggest that LBM gains in resistance trained are not significantly influenced by the type of training stimulus over an 8-week training period.
Low‐load blood flow restricted resistance exercise (BFRE) performed to volitional failure is suggested to constitute an effective method for producing increases in muscle size and function. However, failure BFRE may entail high levels of perceived exertion, discomfort and/or delayed onset of muscle soreness (DOMS). The aim of the study was to compare BFRE performed to volitional failure (F‐BFRE) vs non‐failure BFRE (NF‐BFRE) on changes in muscle size, function and perceptual responses. Fourteen young untrained males had one leg randomized to knee‐extension F‐BFRE while the contralateral leg performed NF‐BFRE. The training consisted of 22 training bouts over an 8‐week period. Whole‐muscle cross‐sectional area (CSA) of quadriceps components, muscle function, and DOMS were assessed before and after the training period. Perceived exertion and discomfort were registered during each training bout. Both F‐BFRE and NF‐BFRE produced regional increases in muscle CSA in the range of; quadriceps (2.5‐3.8%), vastus lateralis (8.1‐8.5%), and rectus femoris (7.9‐25.0%). All without differences between leg. Muscle strength (6.8‐11.5%) and strength‐endurance capacity (13.9‐18.6%) also increased to a similar degree in both legs. Less perceived exertion, discomfort and DOMS were reported with NF‐BFRE compared to F‐BFRE. In conclusion, non‐failure BFRE enable increases in muscle size and muscle function, while involving reduced perceptions of exertion, discomfort and DOMS. Non‐failure BFRE may be a more feasible approach in clinical settings.
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Introduction: The purpose of the present study was to compare the effects of different volumes of resistance training (RT) on muscle performance and hypertrophy in trained women. Methods: The study included 40 volunteers that performed RT for 24 weeks divided in to groups that performed five (G5), 10 (G10), 15 (G15) and 20 (G20) sets per muscle group per session. Ten repetition maximum (10RM) tests were performed for the bench press, lat pull down, 45º leg press, and stiff legged deadlift. Muscle thickness (MT) was measured using ultrasound at biceps brachii, triceps brachii, pectoralis major, quadriceps femoris, and gluteus maximus. Results: All groups significantly increased all MT measures and 10RM tests after 24 weeks of RT (p<0.05). Between group comparisons revealed no differences in any 10RM test between G5 and G10 (p>0.05). G5 and G10 showed significantly greater 10RM increases than G15 for lat pulldown, leg press and stiff legged deadlift. 10RM changes for G20 were lower than all other groups for all exercises (p<0.05). G5 and G10 showed significantly greater MT increases than G15 and G20 in all sites (p<0.05). MT increased more in G15 than G20 in all sites (p<0.05). G5 increases were
higher than G10 for pectoralis major MT, while G10 showed higher increases in quadriceps MT
than G5 (p<0.05). Conclusions: Five to 10 sets per week might be sufficient for attaining gains
in muscle size and strength in trained women during a 24-week RT program. There appears no
further benefit by performing higher exercise volumes. Since lack of time is a commonly cited
barrier to exercise adoption, our data supports RT programs that are less time consuming, which
might increase participation and adherence.
An inability to lift loads great enough to disrupt muscular blood flow may impair the ability to fatigue muscles, compromising the hypertrophic response. It is unknown what level of blood flow restriction (BFR) pressure, if any, is necessary to reach failure at very low-loads [i.e., 15% one-repetition maximum (1RM)]. The purpose of this study was to investigate muscular adaptations following resistance training with a very low-load alone (15/0), with moderate BFR (15/40), or with high BFR (15/80), and compare them to traditional high-load (70/0) resistance training. Using a within/between subject design, healthy young participants (n = 40) performed four sets of unilateral knee extension to failure (up to 90 repetitions/set), twice per week for 8 weeks. Data presented as mean change (95% CI). There was a condition by time interaction for 1RM (p < 0.001), which increased for 70/0 [3.15 (2.04,4.25) kg] only. A condition by time interaction (p = 0.028) revealed greater changes in endurance for 15/80 [6 (4,8) repetitions] compared to 15/0 [4 (2,6) repetitions] and 70/0 [4 (2,5) repetitions]. There was a main effect of time for isometric MVC [change = 10.51 (3.87,17.16) Nm, p = 0.002] and isokinetic MVC at 180°/s [change = 8.61 (5.54,11.68) Nm, p < 0.001], however there was no change in isokinetic MVC at 60°/s [2.45 (−1.84,6.74) Nm, p = 0.261]. Anterior and lateral muscle thickness was assessed at 30, 40, 50, and 60% of the upper leg. There was no condition by time interaction for muscle thickness sites (all p ≥ 0.313). There was a main effect of time for all sites, with increases over time (all p < 0.001). With the exception of the 30% lateral site (p = 0.059) there was also a main effect of condition (all p < 0.001). Generally, 70/0 was greater. Average weekly volume increased for all conditions across the 8 weeks, and was greatest for 70/0 followed by 15/0, 15/40, then 15/80. With the exception of 1RM, changes in strength and muscle size were similar regardless of load or restriction. The workload required to elicit these changes lowered with increased BFR pressure. These findings may be pertinent to rehabilitative settings, future research, and program design.
We examined the effects of resistance training (RT) frequency performed 3 times per week (RT3) versus RT performed 6 times per week (RT6) under volume-equated conditions in resistance-trained men. Twenty-seven men were randomly allocated to RT3 (n = 14) or RT6 (n = 13). The supervised training intervention lasted for 6-weeks. Upper and lower-body strength were assessed using the one-repetition maximum (1RM) test. Also, muscular endurance (60% 1RM performed to momentary failure), and muscle thickness (elbow flexors, elbow extensors, rectus femoris, and vastus intermedius) were measured pre and post-intervention. Pre-to-post intervention, both groups increased upper-body strength (RT3: +4%; RT6: +6%) and lower-body strength (RT3: +22%; RT6: +18%) with no significant between-group differences. No significant pre-to-post intervention increases in muscular endurance were seen in either of the training groups. Both groups increased elbow extensor thickness (RT3: +14%; RT6: +11%), rectus femoris thickness (RT3: +5%; RT6: +6%), and vastus intermedius thickness (RT3: +10%; RT6: +11%) with no significant between-group differences. Only the RT3 group significantly increased elbow flexor thickness from pre-to-post intervention (+7%). When training volume is equated, it seems that RT performed either 3 or 6 times per week can result in similar strength gains over a 6-week training period. Furthermore, under volume-equated conditions, comparable hypertrophy results may also be expected with both RT frequencies. Finally, no changes were seen in muscular endurance possibly because of the considerable inter-individual variability in the responses. The findings presented herein might be of interest to coaches, exercise practitioners, athletes, and recreational trainees.
Purpose:
The purpose of this study was to evaluate muscular adaptations between low-, moderate-, and high-volume resistance training (RT) protocols in resistance-trained men.
Methods:
Thirty-four healthy resistance-trained men were randomly assigned to 1 of 3 experimental groups: a low-volume group (1SET) performing 1 set per exercise per training session (n = 11); a moderate-volume group (3SET) performing 3 sets per exercise per training session (n = 12); or a high-volume group (5SET) performing 5 sets per exercise per training session (n = 11). Training for all routines consisted of three weekly sessions performed on non-consecutive days for 8 weeks. Muscular strength was evaluated with 1 repetition maximum (RM) testing for the squat and bench press. Upper-body muscle endurance was evaluated using 50% of subjects bench press 1RM performed to momentary failure. Muscle hypertrophy was evaluated using B-mode ultrasonography for the elbow flexors, elbow extensors, mid-thigh and lateral thigh.
Results:
Results showed significant pre-to-post intervention increases in strength and endurance in all groups, with no significant between-group differences. Alternatively, while all groups increased muscle size in most of the measured sites from pre-to-post intervention, significant increases favoring the higher volume conditions were seen for the elbow flexors, mid-thigh, and lateral thigh.
Conclusion:
Marked increases in strength and endurance can be attained by resistance-trained individuals with just three, 13-minute weekly sessions over an 8-week period, and these gains are similar to that achieved with a substantially greater time commitment. Alternatively, muscle hypertrophy follows a dose-response relationship, with increasingly greater gains achieved with higher training volumes.
PurposeMuscular strength is suggested to be dependent upon muscle characteristics. Yet, sex-specific relationships of muscle characteristics to strength in the resistance-trained require investigation. Therefore, the purpose was to evaluate sex differences in muscle characteristics and isometric strength in the elbow extensors, as well as their respective associations. Methods
Resistance-trained men (n = 15, mean ± SD 22 ± 4 years, 87.5 ± 12.8 kg, 16.9 ± 2.9% body fat) and women (n = 15, mean ± SD 25 ± 5 years, 59.3 ± 7.3 kg, 22.4 ± 4.2% body fat) were tested. B-mode ultrasound images assessed muscle thickness, pennation angle, and echo intensity. Muscle volume and fascicle length were estimated from previously validated equations. Maximal voluntary isometric contraction measured elbow extensors isometric strength. Independent samples t-tests and Fisher’s r-to-z test examined differences between sexes. ResultsSex differences existed in all muscle characteristics (p < 0.05). Men’s absolute strength (27.86 ± 3.55 kg) was significantly greater than women (16.15 ± 3.15 kg), but no differences were noted when controlling for muscle volume (men 0.069 ± 0.017, women 0.077 ± 0.022 kg/cm3). Sex differences did not exist in the relationships of muscle characteristics to strength with muscle size having the largest correlations. However, the relationship between echo intensity and body fat was different in men (r = − 0.311) and women (r = 0.541, p = 0.0143). Conclusions
Sex differences in isometric elbow extensor strength are eliminated when expressed relative to muscle volume. Relationships of echo intensity and body fat were different between men and women and may be indicative of greater adipose infiltration in women.
The purpose of this study was to compare the effects between single-set vs. multiple-sets of resistance training (RT) on measures of muscular strength, muscle mass, muscle quality (MQ) and insulin-like growth factor 1 (IGF-1) in untrained healthy older women. Sixty-two older women were randomly assigned to one of the three groups: single-set RT (SS, n = 21), multiple-sets RT (MS, n = 20), or non-training control (CG, n = 21). Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum (RM) for each exercise. The SS group performed only 1 set per exercise whereas MS performed 3 sets. Anthropometric, muscle strength (1RM tests), lean soft tissue (LST) and MQ from upper (UL) and lower limbs (LL), and IGF-1 were measured pre- and post-training. Both training groups showed significant pre- to post-training increases for UL1RM (SS: 37.1%, MS: 27.3%, CG: -3.0%), LL1RM (SS: 16.3%, MS: 21.7%, CG: -0.7%), ULLST (SS: 7.8%, MS: 8.8%, CG: -1.1%), LLLST (SS: 5.6%, MS: 6.3%, CG: -0.8%), ULMQ (SS: 25.2%, MS: 16.7%, CG: -0.2%), LLMQ (SS: 10.5%, MS: 15.4%, CG: -3.5%), IGF-1 (SS: +7.1%, MS: +10.1%, CG: -2.2%). We conclude that both SS and MS produce similar increases in muscular strength, LST and MQ of upper and lower limbs, and IGF-1 after 12 weeks of RT in untrained older women. Our results suggest that, in the early stages, the RT regardless number of sets is effective for improving muscular outcomes in this population.
Numerous reports suggest there are low and high skeletal muscle hypertrophic responders following weeks to months of structured resistance exercise training (referred to as low and high responders herein). Specifically, divergent alterations in muscle fiber cross sectional area (fCSA), vastus lateralis thickness, and whole body lean tissue mass have been shown to occur in high versus low responders. Differential responses in ribosome biogenesis and subsequent protein synthetic rates during training seemingly explain some of this individual variation in humans, and mechanistic in vitro and rodent studies provide further evidence that ribosome biogenesis is critical for muscle hypertrophy. High responders may experience a greater increase in satellite cell proliferation during training versus low responders. This phenomenon could serve to maintain an adequate myonuclear domain size or assist in extracellular remodeling to support myofiber growth. High responders may also express a muscle microRNA profile during training that enhances insulin-like growth factor-1 (IGF-1) mRNA expression, although more studies are needed to better validate this mechanism. Higher intramuscular androgen receptor protein content has been reported in high versus low responders following training, and this mechanism may enhance the hypertrophic effects of testosterone during training. While high responders likely possess “good genetics,” such evidence has been confined to single gene candidates which typically share marginal variance with hypertrophic outcomes following training (e.g., different myostatin and IGF-1 alleles). Limited evidence also suggests pre-training muscle fiber type composition and self-reported dietary habits (e.g., calorie and protein intake) do not differ between high versus low responders. Only a handful of studies have examined muscle biomarkers that are differentially expressed between low versus high responders. Thus, other molecular and physiological variables which could potentially affect the skeletal muscle hypertrophic response to resistance exercise training are also discussed including rDNA copy number, extracellular matrix and connective tissue properties, the inflammatory response to training, and mitochondrial as well as vascular characteristics.
Background: This study investigated the effect of volume-matched strength training programs with different frequency and subsequent detraining on muscle size and strength.
Methods: During a training period of 11 weeks, untrained subjects (age: 22.3 ± 0.9 years, height: 173.1 ± 4.8 cm and body mass: 66.8 ± 8.4 kg) performed knee-extension exercise at 67% of their estimated one-repetition maximum either one session per week (T1 group: 6 sets of 12 repetitions per session; n = 10) or three sessions per week (T3 group: 2 sets of 12 repetitions per session; n = 10). Rating of perceived exertion (RPE) and muscle stiffness were measured as an index of muscle fatigue and muscle damage, respectively. The magnitude of muscle hypertrophy was assessed with thigh circumference and the quadriceps muscle thickness. The changes in muscle strength were measured with isometric maximum voluntary contraction torque (MVC).
Results: During the training period, RPE was significantly higher in the T1 than in the T3 (p < 0.001). After 11 weeks of training, both groups exhibited significant improvements in thigh circumference, muscle thickness, and MVC compared with baseline values. However, there was a significant group difference in MVC improvement at week 11 (T1: 43.5 ± 15.5%, T3: 65.2 ± 23.2%, p < 0.05). After 6 weeks of detraining, both groups showed the significant decreases in thigh circumference and muscle thickness from those at the end of training period, while no significant effect of detraining was observed in MVC.
Conclusion: These results suggest that three training sessions per week with two sets are recommended for untrained subjects to improve muscle strength while minimizing fatigue compared to one session per week with six sets.
Background
The objective of the present study was to compare the effects of equal-volume resistance training (RT) performed with different training frequencies on muscle size and strength in trained young men.
Methods
Sixteen men with at least one year of RT experience were divided into two groups, G1 and G2, that trained each muscle group once and twice a week, respectively, for 10 weeks. Elbow flexor muscle thickness (MT) was measured using a B-Mode ultrasound and concentric peak torque of elbow extensors and flexors were assessed by an isokinetic dynamometer.
Results
ANOVA did not reveal group by time interactions for any variable, indicating no difference between groups for the changes in MT or PT of elbow flexors and extensors. Notwithstanding, MT of elbow flexors increased significantly (3.1%, P < 0.05) only in G1. PT of elbow flexors and extensors did not increase significantly for any group.
Discussion
The present study suggest that there were no differences in the results promoted by equal-volume resistance training performed once or twice a week on upper body muscle strength in trained men. Only the group performing one session per week significantly increased the MT of their elbow flexors. However, with either once or twice a week training, adaptations appear largely minimal in previously trained males.
Health authorities worldwide recommend 2-3 days per week of resistance training (RT) performed ~48-72 h apart. However, the influence of recovery period between RT sessions on muscle strength, body composition and red blood cells (RBCs) are unclear.
Aim: Examine the effects of three consecutive (C) or nonconsecutive (NC) days of RT per week for 12 weeks on strength, body composition and RBCs.
Methods: Thirty young, healthy and recreationally active males were randomly assigned to 3 C (~24 h between sessions) or NC (~48-72 h between sessions) days of RT per week for 12 weeks. Both groups performed 3 sets of 10 repetitions at 10-repetition maximum (RM) of leg press, latissimus pulldown, leg curl, shoulder press and leg extension for each session. Ten RM and body composition were assessed pre- and post-RT. RBC parameters were measured on the first session before RT, and 0 and 24 h post-3rd session in untrained (week 1) and trained (week 12) states.
Results: No training x group interaction was found for all strength and body composition parameters (p = 0.075-0.974). Training increased strength for all exercises, bone mineral density, and total body mass via increased lean and bone mass (p < 0.001). There was no interaction (p = 0.076-0.994) and RT induced temporal changes in all RBC parameters (p < 0.001-0.003) except RBC corrected for plasma volume changes (time x training interaction; p = 0.001). Training increased hematocrit and lowered mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration (p = 0.001-0.041) but did not alter uncorrected RBC, hemoglobin, mean corpuscular volume and RBC distribution width (p = 0.178-0.797).
Conclusion: Both C and NC RT induced similar improvements in strength and body composition, and changes in RBC parameters.
The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40); 60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre, post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and 19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p > .05). G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p < .05). There was time effect for elbow flexion and unilateral leg press strength for all groups post-12 weeks (p < .05). However, the magnitude of increase was higher in G60 and G80. In conclusion, when low to high intensities of RT are performed with volume-matched, all intensities were effective for increasing muscle strength and size; however, 20% 1RM was suboptimal in this regard, and only the heavier RT intensity (80% 1RM) was shown superior for increasing strength and CSA compared to low intensities.
The purpose of this study was to investigate the effects of using an internal versus external focus of attention during resistance training on muscular adaptations. Thirty untrained college-aged men were randomly assigned to an internal focus group (INTERNAL) that focused on contracting the target muscle during training (n = 15) or an external focus group (EXTERNAL) that focused on the outcome of the lift (n = 15). Training for both routines consisted of 3 weekly sessions performed on non-consecutive days for 8 weeks. Subjects performed 4 sets of 8–12 repetitions per exercise. Changes in strength were assessed by six repetition maximum in the biceps curl and isometric maximal voluntary contraction in knee extension and elbow flexion. Changes in muscle thickness for the elbow flexors and quadriceps were assessed by ultrasound. Results show significantly greater increases in elbow flexor thickness in INTERNAL versus EXTERNAL (12.4% vs. 6.9%, respectively); similar changes were noted in quadriceps thickness. Isometric elbow flexion strength was greater for INTERNAL while isometric knee extension strength was greater for EXTERNAL, although neither reached statistical significance. The findings lend support to the use of a mind–muscle connection to enhance muscle hypertrophy.
The purpose of this study was to investigate the chronic effects of training muscle groups 1 day per week vs. 2 days per week on neuromuscular performance and morphological adaptations in trained men with the number of sets per muscle group equated between conditions. Participants were randomly assigned in 2 experimental groups: 1 session·wk-1 per muscle group (G1, n = 10), where every muscle group was trained once a week with 16 sets or 2 sessions·wk-1 per muscle group (G2, n = 10), where every muscle group was trained twice a week with 8 sets per session. All other variables were held constant over the 8-week study period. No significant difference between conditions for maximal strength in the back squat or bench press, muscle thickness in the elbow extensors, elbow flexors, or quadriceps femoris, and muscle endurance in the back squat and bench press performed at 60% 1RM was detected. Effect size favored G2 for some outcome measurements, suggesting the potential of a slight benefit to the higher training frequency. In conclusion, both G1 and G2 significantly enhance neuromuscular adaptations, with a similar change noted between experimental conditions.
Keywords: Split body routine; resistance training frequency; muscle hypertrophy; maximal strength.
The present study aimed to compare the effects of equal-volume resistance training performed with single-joint (SJ) or multi-joint exercises (MJ) on VO2max, muscle strength and body composition in physically active males. Thirty-six participants were divided in two groups: SJ group (n = 18, 182.1 ± 5.2, 80.03 ± 2.78 kg, 23.5 ± 2.7 years) exercised with only SJ exercises (e.g., dumbbell fly, knee extension, etc.) and MJ group (n = 18, 185.3 ± 3.6 cm, 80.69 ± 2.98 kg, 25.5 ± 3.8 years) with only MJ exercises (e.g., bench press, squat, etc.). The total work volume (repetitions × sets × load) was equated between groups. Training was performed three times a week for 8 weeks. Before and after the training period, participants were tested for VO2max, body composition, 1 RM on the bench press, knee extension and squat. Analysis of covariance (ANCOVA) was used to compare post training values between groups, using baseline values as covariates. According to the results, both groups decreased body fat and increased fat free mass with no difference between them. Whilst both groups significantly increased cardiorespiratory fitness and maximal strength, the improvements in MJ group were higher than for SJ in VO2max (5.1 and 12.5% for SJ and MJ), bench press 1 RM (8.1 and 10.9% for SJ and MJ), knee extension 1 RM (12.4 and 18.9% for SJ and MJ) and squat 1 RM (8.3 and 13.8% for SJ and MJ). In conclusion, when total work volume was equated, RT programs involving MJ exercises appear to be more efficient for improving muscle strength and maximal oxygen consumption than programs involving SJ exercises, but no differences were found for body composition.
Background
Rest interval (RI) duration is an important resistance-training variable underlying gain in muscular strength. Recommendations for optimal RI duration for gains in muscular strength are largely inferred from studies examining the acute resistance training effects, and the generalizability of such findings to chronic adaptations is uncertain.
Objective
The goals of this systematic literature review are: (i) to aggregate findings and interpret the studies that assessed chronic muscular strength adaptations to resistance training interventions involving different RI durations, and (ii) to provide evidence-based recommendations for exercise practitioners and athletes.
Methods
The review was performed according to the PRISMA guidelines with a literature search encompassing five databases. Methodological quality of the studies was evaluated using a modified version of the Downs and Black checklist.
Results
Twenty-three studies comprising a total of 491 participants (413 males and 78 females) were found to meet the inclusion criteria. All studies were classified as being of good to moderate methodological quality; none of the studies were of poor methodological quality.
Conclusion
The current literature shows that robust gains in muscular strength can be achieved even with short RIs (< 60 s). However, it seems that longer duration RIs (> 2 min) are required to maximize strength gains in resistance-trained individuals. With regard to untrained individuals, it seems that short to moderate RIs (60–120 s) are sufficient for maximizing muscular strength gains.
The purpose of this paper was to conduct a systematic review of the current body of literature and a meta-analysis to compare changes in strength and hypertrophy between low- versus high-load resistance training protocols. Searches of PubMed/MEDLINE, Cochrane Library and Scopus were conducted for studies that met the following criteria: 1) an experimental trial involving both low- (≤60% 1 RM) and high- (>60% 1 RM) load training; 2) with all sets in the training protocols being performed to momentary muscular failure; 3) at least one method of estimating changes in muscle mass and/or dynamic, isometric or isokinetic strength was used; 4) the training protocol lasted for a minimum of 6 weeks; 5) the study involved participants with no known medical conditions or injuries impairing training capacity. A total of 21 studies were ultimately included for analysis. Gains in 1RM strength were significantly greater in favor of high- versus low-load training, while no significant differences were found for isometric strength between conditions. Changes in measures of muscle hypertrophy were similar between conditions. The findings indicate that maximal strength benefits are obtained from the use of heavy loads while muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
Objective
We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength.
Data sources
A systematic search of Medline, Embase, CINAHL and SportDiscus.
Eligibility criteria
Only randomised controlled trials with RET ≥6 weeks in duration and dietary protein supplementation.
Design
Random-effects meta-analyses and meta-regressions with four a priori determined covariates. Two-phase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM).
Results
Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes (means (95% CI)) in: strength—one-repetition-maximum (2.49 kg (0.64, 4.33)), FFM (0.30 kg (0.09, 0.52)) and muscle size—muscle fibre cross-sectional area (CSA; 310 µm² (51, 570)) and mid-femur CSA (7.2 mm² (0.20, 14.30)) during periods of prolonged RET. The impact of protein supplementation on gains in FFM was reduced with increasing age (−0.01 kg (−0.02,–0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM.
Summary/conclusion
Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.
Twenty young women (20.3+1.5 years, 164+6 cm, 68.7+13.8 kg) without prior structured resistance training experience were recruited for this study. Body composition (BodPod), compartmental water (Bioelectrical Impedance), 7-site skinfold, and arm and thigh CSA were assessed pre- and post- 8 week training. Performance testing consisted of vertical jump, 3 kg chest pass initial velocity, squat 1RM and overhead press 1RM. Following 2 weeks of familiarization training, subjects were matched for body composition and relative squat strength, and randomly assigned to either a high- (HL: n=10; 4 sets of 5-7 repetitions) or moderate-load (ML: n=10; 2 sets of 10-14 repetitions) group that completed 6-7 exercises per day performed to momentary muscular failure. Training was divided into two lower and one upper body training sessions per week performed on non-consecutive days for 8 weeks. There were no statistically significant main effects for group or group x time interactions for any variable assessed. Both HL and ML resulted in similar significant increases in lean body mass (1.5 + .83 kg), lean dry mass (1.32 + 0.62 kg), thigh CSA (6.6 + 5.6 cm), vertical jump (2.9 + 3.2 cm), chest pass velocity (0.334 + 1.67 m/s), back squat 1 RM (22.5 + 8.1 kg), and overhead press (3.0 + 0.8 kg). HL and ML also both resulted in significant decreases in percent body fat (1.3 + 1.3 %), total body water (0.73 + 0.70 L), and intracellular water (0.43 + 0.38 L). The results of this study indicate that both moderate- and high-load training are effective at improving muscle growth, body composition, strength and power in untrained young women.
Although the effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy have been investigated in several studies, the findings are equivocal and the practical implications remain unclear. In an attempt to provide clarity on the topic, we performed a systematic literature search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Physiotherapy Evidence Database (PEDro) electronic databases. Six studies were found to have met the inclusion criteria: (a) an experimental trial published in an English-language peer-reviewed journal; (b) the study compared the use of short (≤60 s) to long (>60 s) inter-set rest intervals in a traditional dynamic resistance exercise using both concentric and eccentric muscle actions, with the only difference in resistance training among groups being the inter-set rest interval duration; (c) at least one method of measuring changes in muscle mass was used in the study; (d) the study lasted for a minimum of four weeks, employed a training frequency of ≥2 resistance training days per week, and (e) used human participants without known chronic disease or injury. Current evidence indicates that both short and long inter-set rest intervals may be useful when training for achieving gains in muscle hypertrophy. Novel findings involving trained participants using measures sensitive to detect changes in muscle hypertrophy suggest a possible advantage for the use of long rest intervals to elicit hypertrophic effects. However, due to the paucity of studies with similar designs, further research is needed to provide a clear differentiation between these two approaches.
Background
Periodization is a logical method of organizing training into sequential phases and cyclical time periods in order to increase the potential for achieving specific performance goals while minimizing the potential for overtraining. Periodized resistance training plans are proposed to be superior to non-periodized training plans for enhancing maximal strength. Objective
The primary aim of this study was to examine the previous literature comparing periodized resistance training plans to non-periodized resistance training plans and determine a quantitative estimate of effect on maximal strength. Methods
All studies included in the meta-analysis met the following inclusion criteria: (1) peer-reviewed publication; (2) published in English; (3) comparison of a periodized resistance training group to a non-periodized resistance training group; (4) maximal strength measured by 1-repetition maximum (1RM) squat, bench press, or leg press. Data were extracted and independently coded by two authors. Random-effects models were used to aggregate a mean effect size (ES), 95% confidence intervals (CIs) and potential moderators. ResultsThe cumulative results of 81 effects gathered from 18 studies published between 1988 and 2015 indicated that the magnitude of improvement in 1RM following periodized resistance training was greater than non-periodized resistance training (ES = 0.43, 95% CI 0.27–0.58; P < 0.001). Periodization model (β = 0.51; P = 0.0010), training status (β = −0.59; P = 0.0305), study length (β = 0.03; P = 0.0067), and training frequency (β = 0.46; P = 0.0123) were associated with a change in 1RM. These results indicate that undulating programs were more favorable for strength gains. Improvements in 1RM were greater among untrained participants. Additionally, higher training frequency and longer study length were associated with larger improvements in 1RM. Conclusion
These results suggest that periodized resistance training plans have a moderate effect on 1RM compared to non-periodized training plans. Variation in training stimuli appears to be vital for increasing maximal strength, and longer periods of higher training frequency may be preferred.