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The influence of direct supervision of resistance training on strength performance
Abstract
The purpose of this study was to compare changes in maximal strength, power, and muscular endurance after 12 wk of periodized heavy-resistance training directly supervised by a personal trainer (SUP) versus unsupervised training (UNSUP).
Twenty moderately trained men aged 24.6 +/- 1.0 yr (mean +/- SE) were randomly assigned to either the SUP group (N = 10) or the UNSUP group (N = 8). Both groups performed identical linear periodized resistance training programs consisting of preparatory (10-12 repetitions maximum (RM)), hypertrophy (8 to 10-RM), strength (5 to 8-RM), and peaking phases (3 to 6-RM) using free-weight and variable-resistance machine exercises. Subjects were tested for maximal squat and bench press strength (1-RM), squat jump power output, bench press muscular endurance, and body composition at week 0 and after 12 wk of training.
Mean training loads (kg per set) per week were significantly (P < 0.05) greater in the SUP group than the UNSUP group at weeks 7 through 11 for the squat, and weeks 3 and 7 through 12 for the bench press exercises. The rates of increase (slope) of squat and bench press kg per set were significantly greater in the SUP group. Maximal squat and bench press strength were significantly greater at week 12 in the SUP group. Squat and bench press 1-RM, and mean and peak power output increased significantly after training in both groups. Relative local muscular endurance (80% of 1-RM) was not compromised in either group despite significantly greater loads utilized in bench press muscular endurance testing after training. Body mass, fat mass, and fat-free mass increased significantly after training in the SUP group.
Directly supervised, heavy-resistance training in moderately trained men resulted in a greater rate of training load increase and magnitude which resulted in greater maximal strength gains compared with unsupervised training.
... Organizations with fitness experts guiding physical training have increased physical fitness (25,29), better health, and fewer and less severe musculoskeletal injuries as compared to organizations without expert involvement (29). Qualified fitness professionals can assist athletes in preparing for overall physical activity or specific events. ...
... Fitness experts help International Journal of Exercise Science http://www.intjexersci.com 1328 insure a healthy balance of exercises, nutrition and training resulting in a well-balanced and capable athlete (25,29). ...
... The lower running volume and extended rest time of the TAP-C training group likely explains why the traditional training group performed better on the ACFT 2-mile run event. However, research suggests continuing with the traditional training group program long term may set soldiers up for additional injuries over time compared to the TAP-C training group (2,10,(24)(25)(26). Past injuries have been shown to be highly predictive of future injury and disability (22,31). ...
This study compared an expert supervised, fully resourced physical training (PT) program compared to a traditional physical training PT plan on Army Officer Candidate School (OSC) soldier fitness outcomes. This retrospective cohort study compared 228 OCS soldiers (179 male [26.74±3.78 years] and 49 female [26.55±4.18 years]) in two companies for 12 weeks. One company participated in a fully resourced PT program designed by fitness experts to improve overall fitness and mobility (TAP-C). One company participated in traditional physical training designed to excel on the Army combat fitness test (ACFT, includes deadlift, power throw, push up, sprint-drag-carry, core strength, run) developed and led by OCS soldiers with standard resources. We assessed performance on the ACFT events, and grip strength, standing broad jump, overhead squat, and 90/90 switch assessment. Analysis of covariance was used to compare main effects of company on ACFT measures, controlling for covariates of pretest score differences and sex. Results included a significant effect of group on ACFT performance (N=228), F(1, 223) = 12.8, p<0.001 and on performance of five of the six ACFT events: MDL, F(1, 223) = 5.44, p = 0.021; HRP, F(1, 223) = 11.67, p < 0.001; SDC, F(1, 223) = 20.06, p < 0.001; LTK, F(1, 223) = 16.95, p < 0.001; and 2MR, F(1, 223) = 23.76, p < 0.001. The traditional company performed significantly better on ACFT muscular, anerobic and aerobic endurance focused events; the TAP-C company performed significantly better on muscular strength/explosive power events and mobility assessments.
... SUP within resistance training might be considered important for several reasons: (i). the accurate monitoring of adherence (attendance) and maintenance/continuation [14], (ii). the accurate monitoring and progression of strength training protocols including load progression [19], (iii). the inclusion of technical coaching, which might serve to prevent injury and more effectively target specific muscles by preventing "cheating" [14], (iv). ...
... Most of the studies considered untrained participants [30,31,[45][46][47][48][49][50], whilst two studies considered trained males, the longest with 1-2years [19], and the shortest with ~3months, of training experience [51]. The remaining two studies considered athletic populations [14,52]. ...
... Resistance type varied between studies and was often a combination of free weight, body weight, and resistance machine training. Free weights were the most frequently used resistance modality, appearing in 8 of 12 studies [14,19,30,31,45,46,49,52]. Resistance machines were used in 3 of 12 studies [19,49,52], bodyweight resistance was used in 5 of 12 studies [14,19,45,48,52], and resistance bands in 2 studies [45,48]. ...
Background: Since many people choose to perform resistance training unsupervised, and a lack of supervision within strength training is reported to result in inadequate workout quality, we aimed to compare outcomes for resistance training with and without supervision. Methods: A systematic review and meta-analysis were performed for performance/functional outcomes and/or body composition measurements. Results: 12 studies were included in the review; 301 and 276 participants were in supervised and unsupervised groups, respectively. The main model for all performance/function effects revealed a small, standardised point estimate favouring SUP (0.28 [95%CI = 0.02 to 0.55]). For sub-grouped outcome types, there was very poor precision of robust estimates for speed, power, function, and endurance. However, for strength there was a moderate effect favouring SUP (0.40 [95%CI = 0.06 to 0.74]). The main model for all body composition effects revealed a trivial standardised point estimate favouring SUP (0.07 [95%CI = -0.01 to 0.15]). Conclusions: Supervised resistance training, compared to unsupervised training, might produce a small effect on increases in performance/function, most likely in strength, but has little impact on body composition outcomes.
... However, there are mixed results of whether supervised or unsupervised exercise is more effective. Many researchers have found that supervised programs are more beneficial in improving cardiovascular and muscular fitness than unsupervised interventions [11,[14][15][16]. There is a need to motivate inactive adults to exercise to reduce the risk of developing diseases related to sedentary behavior and to improve overall health. ...
... Even though there will be attrition in any program, this study supports the idea that a supervised program may be an important factor in providing long-term motivation and maintaining a lifestyle that incorporates physical activity and exercise. Another study evaluated the influence of direct supervision during resistance training exercise on strength performance and found direct supervision to increase load and magnitude of results to a greater degree than an unsupervised group performing a similar routine [14]. Additionally, an experiment conducted with health club members found a supervised exercise program with a personal trainer to be more beneficial in increasing lean body mass, strength, and VO 2 max than in a group working without supervision [16]. ...
... The muscular endurance data indicates that a supervised exercise program is more effective at improving this parameter compared to unsupervised exercise, which supports previous research [11,[14][15][16][17]. This muscular endurance data supports the effectiveness of a supervised exercise program compared to unsupervised exercise. ...
... The process of aging is generally accompanied by unavoidable changes in both sensory and motor functions. With old age, muscle mass and consequently, muscle power and torque decrease and these alterations, specifically in postural muscles, can eventually lead to instability and imbalance [1]. Abnormal postural control increases the risk of falling and its subsequent problems, which will decrease the general quality of life (QoL) in older adults. ...
... During the aging process, both strength and the flexibility of the muscles will decrease, especially in the lower extremities. As a result, the elderly cannot apply hip and ankle strategies immediately upon confronting perturbations and this disability can eventually increase the risk of falling [1]. Golding and Lindsay reported a 14.5% reduction in hamstring flexibility for every ten years, which can decrease the hip external rotation by 15% and abduction by 11% [23]. ...
Background: Aging process can deteriorate the ability to maintain balance, specifically under dual-task conditions. Thus far, different methods of exercises therapy have been applied to improve balance performance of older adults. The present study was designed to compare the effects of two protocols of balance training on the quality of life (QoL) and balance performance in older adults with mild balance impairments. Methods: Twenty-four older adults over 60 years old were allocated randomly into single-task (n=12) and dual-task (n=12) exercise groups. Single-task group received routine balance exercises, over a four-week period and dual-task group was treated by the same exercise program plus a cognitive task. QoL and balance status were assessed by the Short-Form Health Survey (SF-36) and Fullerton Advanced Balance scale (FAB) questionnaires, before and after the interventions. Results: After four weeks of training, balance performance and some factors of QoL improved significantly in both groups (P<0.05). However, there were no significant differences in any of the variables between the two groups. Conclusion: Balance exercises, under both single-and dual-task conditions can improve the balance level and some aspects of QoL in older adults with mild balance impairments, with no priority of one group over another.
... Passion for weightlifting has increased in the past few years, by idealizing "RAMBO" (1). Weightlifting focuses on the use of vigorous muscle power and is employed in many athletic activities such as fitness training & sports training (2). ...
... If there is a slight change in angle, a muscle might twitch causing musculoskeletal injuries such as ruptured ligaments, dislocation of joints, injuries of spine and fractures. Dumbbell extensions often put the muscles under a lot of stress which could be avoided under proper supervision (1). According to several studies, it was observed that after following resistance training protocols under supervision, the leg press strength performance along with squat and bench press strength of several trainees increased (1). ...
Background: People nowadays have developed a new passion of weightlifting. Weightlifting focuses on vigorous muscle development. But injuries are also common in weightlifting. This study aims to compare the injury rates among supervised and non-supervised weightlifters.
Methods: A group of 138 weight lifters was divided into two groups i.e. who did training under supervision and the other who did training without any supervision. Injuries related to musculoskeletal system were identified using Nordic musculoskeletal questionnaire. Data was analyzed using SPSS. Chi square test was used to see the association of musculoskeletal pain among weightlifters with or without supervision.
Results: Significant association found between musculoskeletal injuries and supervision. Injuries lesser in number among supervised weightlifters as compared to unsupervised weightlifters. Mean age of weight lifters under supervision and without supervision was 21.99 (SD 3.81) and 24.64 (SD 5.01) respectively. Mean workout days /week among weight lifters under supervision was almost same i.e. 5.67 (SD .63) and was 5.62 (SD .81). Out of 51 participants who work-out for 46-60 min, 30 were not under supervision while 31 weightlifters who work-out for 61-90 min were working out under supervision. Injury rate was more in the region of shoulder in both groups supervised and unsupervised groups while hip/thigh region was less involved in both supervised and unsupervised groups.
Conclusion: Overall results showed significant association between musculoskeletal injuries and supervision. Injury rate was more among weightlifters who work without supervision as compared to those who work under supervision. Care should be taken and weight lifting and exercises must be performed under expert’s supervision.
... The present confusion may partly be attributed to methodological uncertainties in available studies, potentially lowering their ecological validity and explaining their lack of coherence with the resulting meta-analysis data. This includes heterogeneous study populations (varying from young adults 42,44 to older adults 44 to elderly 41,43 ) with large differences in baseline 25(OH)D levels (average 31 nmol/L 43 -71 nmol/L 44 ), large variation in vitamin D dosage (from 400 IU/day 43 -4000 IU/day 42 ), lack of familiarization to strength tests, 41,43 suboptimal training protocols 41,43 (failing to comply to current guidelines, advocating resistance training with controlled maximal effort 45,46 ), low compliance to training, 41,43 and a lack of dietary assessment during the intervention. 41,43,44 Also, neither of the studies included a period of vitamin D supplementation prior to resistance training, which may be necessary to prime muscle cells for adaptations, potentially acting by changing epigenetic traits, which has been observed in other cell types, such as T-cells 47 and oral squamous cell carcinoma cells. ...
... Before assessing the effects of combined vitamin D 3 supplementation and resistance training, it is vital to reaffirm that the protocols and methods held sufficient validity and reliability, including a general assessment of the efficacy of the resistance training intervention. All training sessions were supervised by qualified personnel, as suggested by others, 46 which likely contributed to the very low drop-out rate (n = 4 during the training period,~5%, Table 1), and ensured high adherence to the protocol (98%, range 81-100%, Table 1) and appropriate training progression throughout the intervention (Figure 2). Training volume (repetitions x kg) increased by 20% (knee extension) and 30% (leg press) from Week 14 (the first week of training) to Week 18 (the 4th week of training), by 48% and 54% to Week 22 (the 8th week of training) and by 65% and 68% to Week 27 (the last week of training) (Figure 2). ...
Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve en-docrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. Methods: Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D 3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (n variables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments.
Results: Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, À6% ± 21%; [LDL] serum , À4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, À3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/ 6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D 3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D] serum (Δ49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D] serum. In secondary analyses, vitamin D 3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study.
Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD.
... A prescrição individualizada e o acompanhamento das sessões de treinamento de força (TF) são as principais funções do personal trainer 1 . Além de selecionar a melhor combinação das variáveis agudas do TF, esse profissional deve supervisionar diariamente as sessões de seus clientes para garantir que a técnica e a intensidade adequada sejam utilizadas nos exercícios [1][2][3][4] . Entretanto, existem poucas evidencias na literatura científica que investigaram o efeito da supervisão do personal trainer na sessão de TF de praticantes experientes (>1 ano ininterrupto) com o TF 4 . ...
... Estudos crônicos também apresentam resultados favoráveis à supervisão no TF 2,3 . Mazzetti et al., 3 compararam as mudanças na força máxima, potência e resistência de força após 12 semanas de treinamento periodizado supervisionado ou não por um Personal Trainer. Não foram observadas diferenças na potência e na resistência de força entre os grupos supervisionado e não supervisionado. ...
Supervised resistance training may affect several acute variables such as volume load (VL), the maximum number of repetitions (NRM), time under tension (TUT), and rate of perceived exertion (RPE) in resistance trained-men. The present study aimed to evaluate the influence of the personal trainer’s supervision on a resistance training session in resistance trained-men. Fifteen resistance-trained men (20,0±2 years; 176,0±4 cm; 79,3±4,7 kg) performed two training sessions composed of whole-body exercises. In the session without personal trainer’s supervision (NPT) the subjects self-selected their loads for each exercise and were oriented to “select a load typically employed to perform 10 repetitions”; in the session with personal trainer’s supervision (WPT) the subjects self-selected their loads for each exercise and were oriented to “perform maximum effort”. It was observed greater VL (P<0,001, Δ%=30), NRM (P<0,001, Δ%=29), TUT (P=0,003, Δ%=21), and RPE (P<0,001, Δ%=29) in the resistance training session WPT. The present study concluded that supervised sessions positively affect resistance training variables.
... In addition, Delextrat and Martinez (2014) (Carlo et al., 2011;Conte et al., 2017;Klusemann et al., 2012;McCormick et al., 2012;Schelling & Torres, 2016;Vaquera et al., 2018), rules employed (Conte, Favero, Niederhausen, Capranica, & Tessitore, 2015) and court size (Atlı et al., 2013;Klusemann et al., 2012). The other important variable is direct supervision and coaching can effect player training intensity and performance in game-based training (Coutts, Murphy, & Dascombe, 2004;Mazzetti et al., 2000). ...
The aim of the current study was to examine the acute effects of three different feedback conditions (positive feedback, negative feedback and no feedback) on heart rate, lactic acid, rate of perceived exertion responses and frequencies of technical actions on basketball players during 3-aside full-court games. Twelve young basketball players (Mean age: 16.5 ± 1.5 years; height: 181± 5.9 cm; body mass: 71.4 ± 7 kg; training experience: 5.4 ± 2.1 years) voluntarily participated to the study. The players underwent anthropometric measurements followed by the Yo-Yo intermittent recovery test level 1. Then, players performed 3-aside full-court games under three different conditions with positive verbal feedback, negative verbal feedback and no feedback randomly at 2-day intervals. Repeated measures ANOVAs were used to assess differences among responses to 3-aside full-court games in terms of heart rate, lactic acid, rate of perceived exertion responses and the number of technical actions performed. No significant differences were found between the three feedback conditions nevertheless lactic acid results showed clinical significance in the negative feedback group (5.4±1.7) compared to the group without feedback (6.5±1.8). The findings of this study reveal that positive, negative verbal feedback given by the coach or no feedback does not have an acute effect on basketball players' game performance and internal load responses.
... In addition, Delextrat and Martinez (2014) (Carlo et al., 2011;Conte et al., 2017;Klusemann et al., 2012;McCormick et al., 2012;Schelling & Torres, 2016;Vaquera et al., 2018), rules employed (Conte, Favero, Niederhausen, Capranica, & Tessitore, 2015) and court size (Atlı et al., 2013;Klusemann et al., 2012). The other important variable is direct supervision and coaching can effect player training intensity and performance in game-based training (Coutts, Murphy, & Dascombe, 2004;Mazzetti et al., 2000). ...
The aim of the current study was to examine the acute effects of three different feedback conditions (positive feedback, negative feedback and no feedback) on heart rate, lactic acid, rate of perceived exertion responses and frequencies of technical actions on basketball players during 3-a-side full-court games. Twelve young basketball players (Mean age: 16.5 ± 1.5 years; height: 181± 5.9 cm; body mass: 71.4 ± 7 kg; training experience: 5.4 ± 2.1 years) voluntarily participated to the study. The players underwent anthropometric measurements followed by the Yo-Yo intermittent recovery test level 1. Then, players performed 3-a-side full-court games under three different conditions with positive verbal feedback, negative verbal feedback and no feedback randomly at 2-day intervals. Repeated measures ANOVAs were used to assess differences among responses to 3-a-side full-court games in terms of heart rate, lactic acid, rate of perceived exertion responses and the number of technical actions performed. No significant differences were found between the three feedback conditions nevertheless lactic acid results showed clinical significance in the negative feedback group (5.4±1.7) compared to the group without feedback (6.5±1.8). The findings of this study reveal that positive, negative verbal feedback given by the coach or no feedback does not have an acute effect on basketball players' game performance and internal load responses.
... Another method for stretching is one-to-one personal training. In a 24-week study that consisted of weekly exercise sessions, a control group with minimal supervision vs. those assigned a personal trainer had better adherence (84% vs. 69%) [16]. In the clinical environments, the instructions to help patients do these specific movements correctly are given by the therapist. ...
Background
Smart-bar device (SBD) is a newly developed device to measure the body range of motion (ROM) by a kinetic sensor and to provide an exercise program with augmented reality (AR) guidance of body-frame image and audio feedback by mobile application.
Objective
This study aims to compare the performance of SBD with AR function with a goniometer and to verify the clinical utility of SBD with AR guide function`
Methods
Ten healthy individuals were enrolled and measured the ROM of body lateral flexion, extension, and rotation using a goniometer and SBD simultaneously. To evaluate the accuracy of an AR-guided exercise, we enrolled three patients with adolescent idiopathic scoliosis and measured the ROM of trunk lateral flexion and rotation during stretching exercises using SBD with or without AR guidance.
Results
Concurrent validity between the goniometer and SBD was statistically significant, with a very high correlation coefficient from r = 0.836–0.988 ( p < 0.05). All patients with scoliosis showed higher accuracy when we used SBD with AR guidance than when we used SBD without AR guidance ( p < 0.05).
Conclusions
The SBD could be a valid device to measure the joint angle of neck, shoulder, and trunk. AR guidance increased the accuracy of the stretching exercise, and mobile application of AR-guided stretching exercises with SBD should be useful for scoliosis patients to correct their posture.
... However, concerning strength training regimes, it was reported that supervision can lead to superior results in outcome parameters such as strength compared to non-supervised training regimes. 44,45 While it is likely most of the eligible studies in our meta-analysis excluded non-committed participants, meaning those who failed to perform a certain percentage of the stretch training, it should still be noted that the fully supervised studies in our meta-analysis showed the highest ESs (ES = À1.08) compared to periodically (ES = À0.75) or nonsupervised (ES = À0.74) ...
Background:
It is well known that stretch training can induce prolonged increases in joint range of motion (ROM). However, to date more information is needed regarding which training variables might have greater influence on improvements in flexibility. Thus, the purpose of this meta-analysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables, such as stretching technique, intensity, duration, frequency, and muscles stretched, as well as sex-specific, age-specific, and/or trained state-specific adaptations to stretch training.
Methods:
We searched through PubMed, Scopus, Web of Science, and SportDiscus to find eligible studies and, finally, assessed the results from 77 studies and 186 effect sizes by applying a random-effect meta-analysis. Moreover, by applying a mixed-effect model, we performed the respective subgroup analyses. To find potential relationships between stretch duration or age and effect sizes, we performed a meta-regression.
Results:
We found a significant overall effect, indicating that stretch training can increase ROM with a moderate effect compared to the controls (effect size = -1.002; Z = -12.074; 95% CI confidence interval: -1.165 to -0.840; p < 0.001; I2 = 74.97). Subgroup analysis showed a significant difference between the stretching techniques (p = 0.01) indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic stretching. Moreover, there was a significant effect between the sexes (p = 0.04), indicating that females showed higher gains in ROM compared to males. However, further moderating analysis showed no significant relation or difference.
Conclusion:
When the goal is to maximize ROM in the long term, proprioceptive neuromuscular facilitation or static stretching, rather than ballistic/dynamic stretching, should be applied. Something to consider in future research as well as sports practice is that neither volume, intensity, nor frequency of stretching were found to play a significant role in ROM yields.
... Algunos de los artículos que reportan estos beneficios muestran más adherencia al trabajo y mayores ganancias cuando hay supervisión que en su ausencia. 46 Actualmente no existe un protocolo estandarizado de evaluación de la fuerza en futbolistas lo que dificulta comparar nuestros resultados con los de otros estudios. 3,13,14,48,49 Los test isocinéticos comúnmente usados no reflejan los movimientos hechos durante un partido de fútbol. ...
Los niveles elevados de fuerza, teóricamente, se relacionan con mejoría en las manifestaciones de la potencia muscular inmediata, que es una variable determinante del rendimiento en el fútbol moderno.OBJETIVO: determinar en futbolistas si el entrenamiento de fuerza en un porcentaje alto (85%) de una repetición máxima (1-RM), buscando el aumento en la fuerza máxima (FM), es más eficaz para mejorar la potencia muscular inmediata que un entrenamiento similar pero al 75% de 1-RM. METODOLOGÍA: sesenta futbolistas de las divisiones inferiores del Deportivo Independiente Medellín fueron divididos aleatoriamente en 2 grupos de 30 jugadores cada uno y se diseñaron los siguientes trabajos de fuerza: el grupo experimental realizó un entrenamiento bilateral e individual de fuerza para los extensores y flexores de la rodilla, consistente en 3 series de 5 repeticiones al 85% de 1-RM, con 5 minutos de descanso entre una y otra serie, 2 veces por semana durante 12 semanas. El grupo control hizo un entrenamiento de fuerza para los mismos músculos, consistente en 3 series de 8 repeticiones al 75% de 1-RM, con 5 minutos de descanso entre una y otra serie, 2 veces por semana durante 12 semanas. Al comienzo del estudio y a las 6 y 12 semanas se hicieron mediciones de fuerza máxima (1-RM) de los extensores y flexores de las rodillas y de la potencia muscular inmediata - velocidad en 20 metros, Squat Jump (SJ) y Countermovement Jump (CMJ). RESULTADOS: aunque los 60 jugadores completaron el entrenamiento de fuerza, sólo se analizaron los datos de 29 del grupo experimental y 27 del grupo control; de los 4 restantes, 2 salieron del equipo y 2 sufrieron lesiones no relacionadas con el entrenamiento. No hubo diferencias significativas entre los dos grupos, en ninguna de las variables ni en ninguna de las 3 mediciones. En la mayoría de las variables - fuerza de los extensores de la rodilla derecha, fuerza de los extensores de la rodilla izquierda, fuerza de los flexores de la rodilla derecha, fuerza de los flexores de la rodilla izquierda, Squat Jump y Countermovement Jump - hubo incrementos estadísticamente significativos (p < 0.05) en cada grupo tanto a las 6 semanas como entre las 6 y las 12 semanas: se exceptuó la velocidad en 20 metros que sólo presentó aumento significativo a las 6 semanas. Para ambos grupos, las correlaciones (r de Pearson) de la fuerza máxima (FM) de los extensores de la rodilla derecha con el SJ y el CMJ fueron de moderadas a fuertes y estadísticamente significativas (p < 0.05) tanto al inicio del estudio como a las 6 y a las 12 semanas de entrenamiento de FM; la correlación con la velocidad en 20 metros se halló sólo al inicio del trabajo. CONCLUSIÓN: el trabajo de FM en intensidades al 75 y 85% de 1-RM produce mejorías significativas en la potencia muscular inmediata.
... From the first to the fourth week, exercises are planned to create muscle adaptation, and after creating adaptation in the first month, from the seconf month, the number of repetitions and the number of muscle sets were added based on Frequency, Intensity, Time, and Type (FITT) principles, and newer exercises were added to the program. Since the research results have shown that doing exercises in the presence of the researcher leads to better results, the researcher was present in all the training sessions [33]. ...
Purpose: Back pain is one of the most common injuries affecting many people worldwide. Core stability exercises are among the training methods for treating back pain. Total body resistance exercises, or TRX, are one of the suspension instability tools that have recently become popular among athletes and coaches. The present study aims to compare the effects of current core stability exercises with suspension exercises using TRX in amateur male soccer players with non-specific chronic back pain. Methods: The current research is a clinical trial study. The study population comprised amateur male soccer players with non-specific chronic back pain. The sample size was determined using Cochran's formula, and according to the inclusion criteria of 30, then, they were randomly divided into two equal groups of suspension exercises at the unstable level (n=15) and core stability at the stable level (n=15). The Visual Analogue Scale was used to obtain the pain intensity, and the surface electromyography and force plate were used to check the activity start time(onset). First, the pre-test evaluations were done in the Mofaghian Neurorehabilitation Laboratory. The subjects performed the exercise protocols for 8 weeks, and once the completion of 8-week exercises, the post-test was performed. Descriptive statistics were used to analyze anthropometric characteristics, the Shapiro-Wilk test for normality of data, covariance, and Man-Whitney tests for comparing the results between two groups at a significance level of 0.05. Results: The results of the covariance analysis test showed a significant difference in the onset time of the electromyography of the muscles between the two groups after 8 weeks of exercises (rectus abdominis, P=0.01; multifidus, P=0.001; transverse abdominis, P=0.001, and external oblique, P=0.001). Also, the Mann-Whitney U test results for comparing the pain intensity between the two groups showed a significant difference (P=0.02). Conclusion: Considering the significant effectiveness of suspension exercises compared to traditional core stability exercises and the reports indicating that suspension exercises have a lower risk of injury associated with unnecessary high loads, using these exercises is recommended in people with low back pain rather than exercises on a stable surface.
... Trainers were specifically responsible for ensuring that exercise prescriptions were followed and attained during a training (e.g., velocity of movement, appropriate spotting, appropriate safety considerations, prescribed rest periods, and proper hydration requirements). Furthermore, it has recently been proven that close supervision of resistance training is essential for maximising strength performance changes [18]. Free weight and machine workouts were included in the 8- ...
The purpose of this study was to determine the effects of short-term equal-volume isotonic training with different workout frequency on upper body, lower body, and muscle girth in male volleyball players. Forty-five male volleyball players were randomly selected from Govt. Degree College Killam, affiliated with Kashmir University (UT) Jammu and Kashmir with mean ± SD: (19.45 ± 3.4 years, height of 177.18 ± 4.15 centimetres, 66.70 ± 5.30 kg and BMI 21.20 ± 3.25 were chosen). The subjects were segregated into three groups; total-body isotonic training, (12 exercises for two sessions per week) (Isotonic G-I=15), upper-body, and lower-body isotonic training (12 exercises for three sessions per week) (Isotonic G-II=15), and control group (CG=15) didn't take part in any special training. Assessments of body composition, height, weight, body mass index, and flexed arm girth, strength (one repetition maximum in bench press) and vertical jump were determined before and after 8 weeks of training. Flexed-arm girth, 1-RM bench press and vertical jump was improved significantly in all training groups (P < 0.05). All groups increased body weight and body composition (P ≤ 0.05), but isotonic G-I group showed a little improvement rather than other isotonic G-II. It is concluded that in healthy young men, whole and split weight training routine produce similar results over the first 2 months of training, with minimal differences among groups.
... Trainers were specifically responsible for ensuring that exercise prescriptions were followed and attained during a training (e.g., velocity of movement, appropriate spotting, appropriate safety considerations, prescribed rest periods, and proper hydration requirements). Furthermore, it has recently been proven that close supervision of resistance training is essential for maximising strength performance changes [18]. Free weight and machine workouts were included in the 8- ...
The purpose of this study was to determine the effects of short-term equal-volume isotonic training with different workout frequency on upper body, lower body, and muscle girth in male volleyball players. Forty-five male volleyball players were randomly selected from Govt. Degree College Killam, affiliated with Kashmir University (UT) Jammu and Kashmir with mean ± SD: (19.45 ± 3.4 years, height of 177.18 ± 4.15 centimetres, 66.70 ± 5.30 kg and BMI 21.20 ± 3.25 were chosen). The subjects were segregated into three groups; total-body isotonic training, (12 exercises for two sessions per week) (Isotonic G-I=15), upper-body, and lower-body isotonic training (12 exercises for three sessions per week) (Isotonic G-II=15), and control group (CG=15) didn't take part in any special training. Assessments of body composition, height, weight, body mass index, and flexed arm girth, strength (one repetition maximum in bench press) and vertical jump were determined before and after 8 weeks of training. Flexed-arm girth, 1-RM bench press and vertical jump was improved significantly in all training groups (P < 0.05). All groups increased body weight and body composition (P ≤ 0.05), but isotonic G-I group showed a little improvement rather than other isotonic G-II. It is concluded that in healthy young men, whole and split weight training routine produce similar results over the first 2 months of training, with minimal differences among groups.
... However, the extent to which volitional fatigue outweighs other established RT principles (i.e., overload, specificity) is controversial and a current area of study. Direct observation of exercise programs is independently associated with enhanced strength gains, hypertrophy, and long-term regimen compliance [127,128]. Limiting these exercise sessions to 60 min may avoid neuromuscular fatigue and the risk of injury [129]. Direct observation and training in group settings may aid in the difficult task of behavioral and motivational changes in these groups, particularly after cancer treatment, while providing additional safety benefits. ...
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.
... Notably, some studies have displayed that utilizing any type of feedback and movement education as part of the intervention can influence the lower extremity kinematics [62,63]. Accordingly, proper performance of exercises in all phases and provision of various types of feedback and movement education may justify improvement in participants' movement patterns [64], and thus lower extremity kinematics and muscle strength, respectively. ...
Background
Dynamic knee valgus (DKV) is a prevalent movement impairment widely regarded as a risk factor for lower extremity disorders such as patellofemoral pain syndrome. The present study aimed to investigate the effectiveness of the comprehensive corrective exercise program (CCEP) on kinematics and strength of lower extremities in males with DKV.
Methods
Thirty asymptomatic young men with DKV between the ages of 18 and 28 years participated in this study. They were randomly assigned to the intervention (n = 15) and control groups (n = 15). The intervention group performed the CCEP for three sessions per week for eight weeks, while the control group only did activities of daily living. Hip external rotator and abductor muscle strength and three-dimensional lower extremity kinematics consisting of knee varus/valgus, femur adduction/abduction, femur medial/lateral rotation, and tibial medial/lateral rotation were measured at the baseline and post-test. The data were analyzed using the analysis of covariance (ANCOVA).
Results
There were significant improvements in all kinematics variables in the intervention group after the 8-week CCEP. Moreover, the strength of abductor and external rotator muscle improved in the intervention group (P < 0.05).
Conclusions
The CCEP led to substantial improvements in the selected variables of lower extremity kinematics and muscle strength in participants with DKV during a single-leg squat. These results imply that practitioners should adopt a comprehensive approach to pay simultaneous attention to both proximal and distal segments for improving DKV.
Trial registration
The protocol has been approved in the Registry of Clinical Trials (Registration N: IRCT20180821040843N1) on 2018-12-30.
... 8:8 sa srdcová frekvencia zvýšila o 10,7% práve v dôsledku brankárov (Dellal et al., 2008). Mnoho autorov sa zhodlo, že verbálny zásah trénera v prípravných hrách so stredným počtom hráčov je jeden z najdôležitejších faktorov, ktorý ovplyvňuje fyzickú odozvu hráčov (Bangsboo, 1998;Balsom, 1999;Coutts et al., 2004;Hoff et al., 2002;Mazzetti et al., 2000a Rampinini et al., 2007. ...
Broďáni Jaroslav, Czaková Monika (2022). Šport a rekreácia 2022 / Sport and recreation 2022. Nitra : DPES EF CPU, ISBN 978-80-558-1905-1, 130 p.
... Supervision within resistance training might be of importance for several reasons: (i). the promotion and accurate monitoring of adherence (attendance) and maintenance/continuation [7], (ii). the accurate monitoring and progression of strength training protocols including load progression [12,38,44] (iii). the inclusion of technical coaching, which might serve to prevent injury and more effectively target specific muscles by preventing "cheating" [7], (iv). ...
Background
Virtual personal training might represent an uncomplicated, accessible, and time-efficient approach to supervised strength training, particularly under government-imposed lockdown or closure of fitness facilities. However, there appears a dearth of literature evaluating the efficacy of virtual personal training.
Methods
The present project considered two studies considering supervised virtual strength training. Study 1 considered trained participants being supervised one-to-one through traditional resistance exercise sessions in a strength training studio (STUD), compared to a virtual personal training protocol performed using bodyweight resistance exercises (VIRT). This study utilized a crossover design whereby male (n=13) and female (n=7) participants were tested for body composition using BodPod, and strength for bench press, leg press, and high-row exercises. Participants were then randomly assigned to 3-weeks of VIRT or 3-weeks of STUD training. Following each 3-week training period, participants had a 1-week period without training whereby mid-intervention testing occurred, after which participants then completed the alternate training intervention. For study 2, we surveyed the client base of a chain of training facilities who had begun offering virtual personal training during lockdown to explore their views on this approach.
Results
Strength and body composition changes were similar between groups, however for neither condition did results surpass the smallest meaningful change. The remaining survey data suggests that supervised virtual resistance training yields similar perceptions of effort, motivation, enjoyment, and supervision quality, compared to traditional supervised studio training.
Conclusion
Based on the current data, it appears that short-term supervised virtual resistance training is as efficacious as traditional supervised studio-based resistance training.
... Lastly, all participants in the current study were followed closely by two skilled fitness professionals, and they completed the interventions with high compliance. In addition, it has been shown that supervised RT by a fitness professional (i.e., personal trainer) results in greater LBM gains than unsupervised RT [29,30]. ...
Purpose This study sought to investigate the impact of different schemes of load intensity transition (LIT, performed until, or close to, voluntary concentric failure) at 12
weeks on lean body mass (LBM) gains in postmenopausal women (PW) after a 24-weeks intervention. Moreover, since changes in LBM after resistance training (RT) vary widely from person to person, this study also investigated how the LIT affects low- and high-responders for RT-induced change in LBM.
Methods Twenty-four participants were randomized into two schemes of LIT: from lower-load RT (LL, ~30% of 1RM) to higher-load RT (HL, ~80% of 1RM) (n = 12, loads necessary to perform 27-31 repetitions during 12 weeks plus 12 weeks with loads necessary to perform 8-12 repetitions) and from HL to LL (n = 12, loads necessary to perform 8-12 repetitions during 12 weeks performing plus 12 weeks with loads necessary to perform 27-31 repetitions). LBM (DXA) was measured at baseline, after 12 and 24 weeks of training.
Results There was a progression of RT volume (load intensity x number of repetitions) (P Time < 0.001) in both schemes (Post hoc: P < 0.05); however, greater volume progression was observed in the LL group in both phases. LL to HL and HL to LL similarly stimulating LBM gains after 12 and 24 weeks of RT ( P < 0.05). Low-responders (no-gains in LBM at 12 weeks of RT) and high-responders for RT at 12 weeks demonstrate LBM gains after the LIT (i.e., at 24 weeks), regardless of the schemes used.
Conclusions Our study suggests that LIT, regardless of the schemes used, is an effective strategy of RT-progression (after 12 weeks) for increasing LBM in PW (low- and high-responders).
... Supervision within resistance training might be of importance for several reasons: (i). the promotion and accurate monitoring of adherence (attendance) and maintenance/continuation (Coutts, et al. 2004), (ii). the accurate monitoring and progression of strength training protocols including load progression (Mazzetti, et al. 2000;Ratamess, et al. 2008;Dias, et al. 2017) (iii). the inclusion of technical coaching, which might serve to prevent injury and more effectively target specific muscles by preventing "cheating" (Coutts, et al. 2004), (iv). ...
Background: Virtual personal training might represent an uncomplicated, accessible, and time-efficient approach to supervised strength training, particularly under government-imposed lockdown or closure of fitness facilities. However, there appears a dearth of literature evaluating the efficacy of virtual personal training. Methods: The present study considered trained participants being supervised one-to-one through traditional resistance exercise sessions in a strength training studio (STUD), compared to a virtual personal training protocol performed using bodyweight resistance exercises (VIRT). The study utilized a crossover design whereby male (n=13) and female (n=7) participants were tested for body composition using BodPod, and strength for bench press, leg press, and high-row exercises. Participants were then randomly assigned to 3-weeks of VIRT or 3-weeks of STUD training. Following each 3-week training period, participants had a 1-week washout period without training whereby mid-intervention testing occurred, after which participants then completed the alternate training intervention. Further, we surveyed the client base of a chain of training facilities who had begun offering virtual personal training during lockdown to explore their views on this approach. Results: Strength and body composition changes were similar between groups, however for neither condition did results surpass the smallest meaningful change. The remaining survey data suggests that supervised virtual resistance training yields similar perceptions of effort, motivation, enjoyment, and supervision quality, compared to traditional supervised studio training. Conclusion: Based on the current data, it appears that short-term supervised virtual resistance training is as efficacious as traditional supervised studio-based resistance training.
... However, there were several limitations; the study design was retrospective in nature as the authors relied on participant questionnaire responses for group assignments, so an inherent self-bias could have led to inaccurate answers and group placement. Additionally, due to the retrospective design, the exercise intervention conducted was not under the supervision of the investigators; previous research has shown larger effects in strength when RET is supervised (Mazzetti et al., 2000;Lacroix et al., 2017). Finally, the authors chose handgrip strength as a surrogate measure of total body strength. ...
Muscle quality (MQ), defined as the amount of strength and/or power per unit of muscle mass, is a novel index of functional capacity that is increasingly relied upon as a critical biomarker of muscle health in low functioning aging and pathophysiological adult populations. Understanding the phenotypical attributes of MQ and how to use it as an assessment tool to explore the efficacy of resistance exercise training interventions that prioritize functional enhancement over increases in muscle size may have implications for populations beyond compromised adults, including healthy young adults who routinely perform physically demanding tasks for competitive or occupational purposes. However, MQ has received far less attention in healthy young populations than it has in compromised adults. Researchers and practitioners continue to rely upon static measures of lean mass or isolated measures of strength and power, rather than using MQ, to assess integrated functional responses to resistance exercise training and physical stress. Therefore, this review will critically examine MQ and the evidence base to establish this metric as a practical and important biomarker for functional capacity and performance in healthy, young populations. Interventions that enhance MQ, such as high-intensity stretch shortening contraction resistance exercise training, will be highlighted. Finally, we will explore the potential to leverage MQ as a practical assessment tool to evaluate function and enhance performance in young populations in non-traditional research settings.
... This ensures that all fibers in a particular muscle have been engaged. Machines work well for developing a custom circuit training program especially when working with a professional or trainer [21]. ...
Foundational Stability, Support, Strength, Symmetry and Balance of the Foot and Lower Extremity is the Predictable Primary Starting Platform for All Closed Chain Stance and Movement
... Moreover, all participants in this study were followed closely by skilled fitness professionals, and they completed the interventions with high compliance. In this regard, it has been shown that supervised DLRT by a fitness professional results in greater muscle mass and muscular strength improvements when compared with unsupervised DLRT [43,44]. ...
Purpose It is not clear whether fat-free mass gains impact negatively on swimming performance in swimmers. Moreover, less is known about the impact of different dry-land resistance training (DLRT) periodization models on body fat changes in swimmers. Hence, this study aimed to test whether block periodization DLRT (DLRT-BP) and daily undulating periodization DLRT (DLRT-DUP) are similar in improving fat-free mass, swimming and physical performance, muscular strength, and body fat in female and male amateur swimmers.
Methods The participants were randomized into three groups: DLRT-BP [n=10, three blocks of training with different intensities (changing each 4-week)], DLRT-DUP [n=10, three sessions of training per week with different intensities (alternating each session)], and control group (n=8, no exercise). Both intervention groups training three times a
week. Muscle mass index (indicator of fat-free mass) and body fat percentage (iDXA), swimming (50-M swim velocity and time) and physical (squat jump) performance, muscular strength (1RM) were analyzed at baseline and after 12-weeks of DLRT.
Results There were similar improvements in fat-free mass, swimming performance, and muscular strength from pre-intervention, and when compared to control group (P < 0.05). However, body fat percentage and squat jump did not change (P > 0.05). Fat-free mass changes explained 17% the improvement in 50-M swim velocity ( r = 0.41,
P = 0.040) in both training groups than control group.
Conclusions Thus, although both DLRT periodization models induce fat-free mass gains (independent of sex), it does not seem to affect the responses in swimming performance and muscular strength in amateur swimmers.
... All stretches were repeated twice and held for 20 s each. All warm-up, resistance training, and cool-down sessions were supervised by a certified strength and conditioning specialist (NSCA-CSCS), who also monitored training loads for each exercise 34 . Whenever five or more participants were on the training floor at once, two certified strength and conditioning specialists supervised the training floor, and a maximum of 10 participants was allowed on the training floor on days 1-4. ...
Purpose:
This study investigated the effects of marine phytoplankton supplementation (Oceanix®, Tetraselmis chuii) on 1) maximal isometric strength and immune function in healthy humans following a oneweek high-intensity resistance-training program and 2) the proinflammatory cytokine response to exercise in a rat model.
Methods:
In the human trial, 22 healthy male and female participants were randomly divided into marine phytoplankton and placebo groups. Following baseline testing, participants underwent a 14-day supplement loading phase before completing five consecutive days of intense resistance training. In the rat model, rats were randomly divided into four groups (n=7 per condition): (i) control, (ii) exercise, (iii) exercise + marine phytoplankton (2.55 mg/kg/day), or (iv) exercise + marine phytoplankton (5.1 mg/kg/day). Rats in the exercising groups performed treadmill exercise 5 days per week for 6 weeks.
Results:
In the human model, marine phytoplankton prevented significant declines in the isometric peak rate of force development compared to placebo. Additionally, salivary immunoglobulin A concentration was significantly lower following the resistance training protocol in the placebo group but not in the marine phytoplankton group. Marine phytoplankton in exercising rats decreased intramuscular levels and serum concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) and intramuscular concentrations of malondialdehyde.
Conclusion:
Marine phytoplankton prevented decrements in indices of functional exercise recovery and immune function. Mechanistically, these outcomes could be prompted by modulating the oxidative stress and proinflammatory cytokine response to exercise.
... All RT sessions were directly supervised by physical education professionals with extensive experience in RT. Given that supervised training promotes greater magnitudes of neuromuscular adaptations when compared with nonsupervised (19), supervision is essential to obtain accurate results. This made it possible to accurately adjust the progressive overload, allowing the intensity zone to be maintained throughout the entire intervention. ...
Two of the foremost principles of progression are progressive overload and variation. A way to vary within a resistance training (RT) program is to perform different exercises for the same muscle group; however, this strategy is still overlooked. The purpose of the present study was to compare strength adaptations between an RT routine that maintained the exercises fixed (N-VAR) and another that varied the exercises for the same muscle group during the weekly sessions (VAR). Twenty-three young men (23.3 ± 4.1 years) were randomly allocated to N-VAR (n = 11) or VAR (n = 12) conditions. The RT was performed three times a week for nine weeks and consisted of a whole-body routine (3 sets of 8–12 repetitions). Maximum dynamic strength was assessed using the one-repetition maximum test (1RM), and the isometric strength using an isokinetic dynamometer, before and after training. Following the training period, both groups increased the 1RM values in all exercises (P ≤ 0.002), without significant differences between them (P ≥ 0.20). In contrast, a greater increase (P = 0.02) in isometric knee extension strength was showed to N-VAR (+12%) compared to VAR (+7%). There was no significant increase in both groups for isometric knee flexion strength (N-VAR, P = 0.10; VAR, P = 0.18). Our findings indicate that maintaining or varying the exercises for the same muscle group promotes similar adaptations in the maximum dynamic strength. In contrast, for the isometric strength in knee extension, maintaining the fixed exercises seems to be more interesting.
... All stretches were repeated twice and held for 20 s each. All warm-up, resistance training, and cool down sessions were supervised by a certified strength and conditioning specialist (NSCA-CSCS) who also monitored training loads for each exercise [26]. Whenever five or more subjects were on the training floor at once, two certified strength and conditioning specialists were supervising the training floor. ...
This study investigated the effects of marine phytoplankton supplementation on 1) perceived recovery and ground reaction forces in humans following a non-functional overreaching resistance-training program and 2) myogenic molecular markers associated with muscle cell recovery in a rat model. In the human trial, a 5-week resistance-training program with intentional overreaching on weeks 2 and 5 was implemented. Results indicate that marine phytoplankton prompted positive changes in perceived recovery at post-testing and, while both marine phytoplankton and placebo conditions demonstrated decreased peak and mean rate of force development following the overreaching weeks, placebo remained decreased at post-testing while marine phytoplankton returned to baseline levels. In the rat model, rats were divided into four conditions: (i) control, (ii) exercise, (iii) exercise + marine phytoplankton 2.55 mg·d-1, or (iv) exercise+marine phytoplankton 5.1 mg·d-1. Rats in exercising conditions performed treadmill exercise 5 d·wk-1 for 6 weeks. Marine phytoplankton in exercising rats increased positive and decrease negative myogenic factors regulating satellite cell proliferation. Taken together, marine phytoplankton improved perceptual and functional indices of exercise recovery in an overreaching human model and, mechanistically, this could be driven through cell cycle regulation and a potential to improve protein turnover.
... Being named as a substitute has been associated with reduced motivation to prepare, 13,26 whilst empirical observations highlight how events unfolding in the match appear to affect the self-selected activities performed by players awaiting pitch-entry. 8 As superior outcomes have been realised following coach-supervised compared with unsupervised training, 27 allowing members of team staff to accompany substitutes during rewarm-ups may enable more varied and better structured pre-pitch-entry preparations compared with when exclusively player-led activities are performed. 1 Despite elevated blood lactate concentrations and progressive increases in RPE, sprint times were not reduced throughout ∼30 min of simulated match-play. ...
Objectives:
To profile performance and physiological responses to typical patterns of match-day activity for second-half soccer substitutes.
Design:
Descriptive.
Methods:
Following a warm-up, 13 male team sports players underwent ∼85min of rest, punctuated with five min rewarm-ups at ∼25, ∼50, and ∼70min, before ∼30min of simulated soccer match-play. Countermovement jump performance (jump height, peak power output), alongside 15m sprints, were assessed post-warm-up, and pre- and post-simulated match-play. Core temperature, heart rate, ratings of perceived exertion, and blood glucose and lactate concentrations were measured throughout.
Results:
Warm-up-induced core temperature elevations (∼2.3%, +0.85°C; p<0.001) were maintained until after the first rewarm-up. Thereafter, core temperature was reduced from post-warm-up values until pre-simulated match-play (∼1.6%, -0.60°C; p<0.001), where values were similar to pre-warm-up (37.07±0.24°C, p=0.981). Simulated match-play increased core temperature progressively (p≤0.05) but values remained lower than post-warm-up (∼5min; p=0.002) until ∼10min into exercise. From post-warm-up to pre-simulated match-play, sprint times (∼3.9%, +0.10s, p=0.003), jump height (∼9.4%, -3.1cm; p=0.017), and peak power output (∼7.2%, -296W; p<0.001) worsened. Despite increased ratings of perceived exertion and elevated blood lactate concentrations (p≤0.05), sprint times were maintained throughout exercise, whereas peak power increased (∼7.8%, +294W; p=0.006) pre- to post-exercise.
Conclusions:
At the point of simulated pitch-entry, body temperature and physical performance responses were not maintained from warm-up cessation despite typical substitute-specific match-day practices being employed in thermoneutral conditions. Evidence of performance-limiting fatigue was absent during ∼30min of simulated match-play. These data question the efficacy of practices typically implemented by substitutes before pitch-entry.
... This ensured subjects to maintain proper lifting form and may have enhanced training effort (independent of CHO timing). Previous research has established that supervised training can produce superior strength outcomes compared with unsupervised training (Mazzetti et al. 2000). There are several limitations that need to be addressed. ...
The purpose of this investigation was to examine the importance of carbohydrate (CHO) timing while consuming a carbohydrate restricted diet (CRD) and completing a high-intensity exercise program. Eighteen males completed 6 weeks of training with the first 2 weeks serving as familiarization. During the final 4 weeks, subjects were randomized into 2 groups and completed 3 days of resistance training and 2 days of high-intensity interval training, while consuming a CRD (∼25%, ∼25%, and ∼50%, CHO, protein, and fat, respectively). The supplemented group (n = 9) ingested 30 g of CHO during exercise and 40 g of CHO immediately after each training session. The non-supplemented group (n = 9) consumed a non-caloric placebo during exercise. Pre- and post-testing measures included back squat and bench press 1-repetition maximums (1-RM), peak oxygen consumption (V̇O 2peak ), anaerobic power, body composition, fasted glucose, insulin, and total testosterone. Both groups significantly improved back squat and bench press 1-RM, V̇O 2peak , and power output (p < 0.05), but there were no differences in blood markers or body composition. Our data suggests that CHO timing does not negatively impact training adaptations during a high-intensity exercise regimen when dietary CHO intake is restricted, but that favorable adaptations can be made while consuming a CRD.
Novelty: Carbohydrate restricted dieting has no negative impact on resistance training adaptations. Short-term high-intensity interval training is effective in increasing peak oxygen consumption.
... As such, readers are cautioned from drawing straight-line conclusions that rice and whey protein are equal until longer and larger investigations have been completed. Some may view our lack of direct exercise training supervision as a limitation, as previous work has indicated that strength increases are greater when direct supervision occurs [42]. However, the impact of supervision on body composition changes remains undetermined. ...
Background
Large (48-g), isonitrogenous doses of rice and whey protein have previously been shown to stimulate similar adaptations to resistance training, but the impact of consuming smaller doses has yet to be compared. We evaluated the ability of 24-g doses of rice or whey protein concentrate to augment adaptations following 8 weeks of resistance training.
Methods
Healthy resistance-trained males ( n = 24, 32.8 ± 6.7 years, 179.3 ± 8.5 cm, 87.4 ± 8.5 kg, 27.2 ± 1.9 kg/m ² , 27.8 ± 6.0% fat) were randomly assigned and matched according to fat-free mass to consume 24-g doses of rice ( n = 12, Growing Naturals, LLC) or whey (n = 12, NutraBio Labs, Inc.) protein concentrate for 8 weeks while completing a standardized resistance training program. Body composition (DXA), muscular strength (one-repetition maximum [1RM]) and endurance (repetitions to fatigue [RTF] at 80% 1RM) using bench press (BP) and leg press (LP) exercises along with anaerobic capacity (Wingate) were assessed before and after the intervention. Subjects were asked to maintain regular dietary habits and record dietary intake every 2 weeks. Outcomes were assessed using 2 × 2 mixed (group x time) factorial ANOVA with repeated measures on time and independent samples t-tests using the change scores from baseline. A p -value of 0.05 and 95% confidence intervals on the changes between groups were used to determine outcomes.
Results
No baseline differences ( p > 0.05) were found for key body composition and performance outcomes. No changes ( p > 0.05) in dietary status occurred within or between groups (34 ± 4 kcal/kg/day, 3.7 ± 0.77 g/kg/day, 1.31 ± 0.28 g/kg/day, 1.87 ± 0.23 g/kg/day) throughout the study for daily relative energy (34 ± 4 kcals/kg/day), carbohydrate (3.7 ± 0.77 g/kg/day), fat (1.31 ± 0.28 g/kg/day), and protein (1.87 ± 0.23 g/kg/day) intake. Significant main effects for time were revealed for body mass ( p = 0.02), total body water ( p = 0.01), lean mass ( p = 0.008), fat-free mass ( p = 0.007), BP 1RM ( p = 0.02), BP volume ( p = 0.04), and LP 1RM ( p = 0.01). Changes between groups were similar for body mass (− 0.88, 2.03 kg, p = 0.42), fat-free mass (− 0.68, 1.99 kg, p = 0.32), lean mass (− 0.73, 1.91 kg, p = 0.37), fat mass (− 0.48, 1.02 kg, p = 0.46), and % fat (− 0.63, 0.71%, p = 0.90). No significant between group differences were seen for BP 1RM (− 13.8, 7.1 kg, p = 0.51), LP 1RM (− 38.8, 49.6 kg, p = 0.80), BP RTF (− 2.02, 0.35 reps, p = 0.16), LP RTF (− 1.7, 3.3 reps, p = 0.50), and Wingate peak power (− 72.5, 53.4 watts, p = 0.76) following the eight-week supplementation period.
Conclusions
Eight weeks of daily isonitrogenous 24-g doses of rice or whey protein in combination with an eight-week resistance training program led to similar changes in body composition and performance outcomes. Retroactively registered on as NCT04411173 .
... Os resultados mostraram que o grupo de alta supervisão (que teve o acompanhamento mais próximo) obteve melhores resultados no condicionamento físico em relação ao grupo de baixa supervisão. Resultados semelhantes foram encontrados quando o objetivo era melhora estética (Mazzetti et al., 2000). Como já foi dito antes, clientes que alcançam seus objetivos tem alta retenção. ...
A quantidade de academias tem crescido no mundo todo assim como o número de pessoas que procuram esse espaço para se exercitar em busca de um objetivo que pode ser estético, de saúde ou esportivo. Com o crescimento do mercado, a competitividade entre as academias também foi elevada. O objetivo desse trabalho é analisar, através de revisão da literatura, as principais estratégias de captação e retenção de clientes, assim como identificar os motivos que levam a evasão de clientes e o que fazer para contorná-los. Foi verificado que a captação de clientes em academias deve ser realizada com posicionamento de marca e produto, além de campanhas publicitárias, especialmente marketing digital, para divulgação dos serviços e produtos oferecidos pela academia. As estratégias de retenção se relacionam com a criação de um canal de comunicação academia-cliente, a qualidade do produto e serviço prestado e também premiações e vantagens para clientes antigos e ativos na academia. As principais causas de evasão de clientes são a falta de tempo para práticar exercícios físicos, o mau atendimento prestado pelo colaboradores e a dificuldade de socializar-se na academia, estes fatores podendo ser evitados com programas de treinamento com menor compromisso de tempo, mas ainda eficientes, treinamento para melhorar o atendimento e aulas especiais coletivas e eventos que possam promover a socialização. Este trabalho poderá auxiliar para gestores de academias no desempenho de suas funções. Palavras-chave: Academias de ginástica; Mercado fitness; Gestão de academias; Marketing. Abstract The number of gyms has grown worldwide as well as the number of people who seek this space to exercise in pursuit of a goal that can be aesthetic, health or sports. With the growth of the market, the competitiveness between the academies was also high. The objective of this work is to analyze, through a literature review, the main strategies of customer capture and retention, as well as to identify the reasons that lead to customer evasion and what to do to get around them. It was verified that the capitation of clients in academies should be performed with brand and product positioning, as well as advertising campaigns, especially digital marketing, to publicize the services and products offered by the academy. Retention strategies relate to the creation of an academic-client communication channel, the quality of the product and service provided, as well as rewards and benefits for old and active clients in the academy. The main causes of client evasion are the lack of time to practice physical exercises, the poor attendance provided by the employees and the difficulty of socializing in the gym, these factors being avoidable with training programs with less time commitment, but still training to improve attendance and special classes and events that can promote socialization. This work may assist academy managers in the performance of their duties. Resumén El número de gimnasios ha crecido en todo el mundo, así como el número de personas que buscan este espacio para hacer ejercicio en busca de un objetivo que puede ser estético, de salud o deportivo. Con el crecimiento del mercado, la competitividad entre las academias también fue alta. El objetivo de este trabajo es analizar, a través de una revisión de la literatura, las principales estrategias para atraer y retener clientes, así como identificar las razones que conducen a la evasión del cliente y qué hacer para evitarlos.
... Por último, la intervención del entrenador en las sesiones genera que los jugadores realicen entrenamientos con una mayor carga, provocando que la intensidad sea distinta (Falces, Casamichana, & Suárez-Arrones, 2013), además, de mejorar su adherencia al entrenamiento (Mazzetti et al., 2000). Hay estudios que se centran en ver el efecto sobre la condición física, tanto en jugadores adultos y jóvenes (Rampinini et al., 2007;Sampaio et al., 2007;Sánchez-Sánchez et al., 2014b), especialmente centrados en la carga interna, o técnica (Sánchez-Sánchez, Rodríguez, Luis-Pereira, & Caro, 2014c). ...
RESUMEN
El objetivo de la investigación fue comparar la influencia del entrenador y de los juegos reducidos sobre la condición física, técnica-táctica y toma de decisiones en jugadores sub-12 de alto nivel de pericia, diferenciando por niveles de los jugadores en función del criterio del entrenador. Participan 12 jugadores, con una edad media de 10,17 años (±,389), peso de 37 (±5,893) Kg. y altura de 144,75 (±6,002) cm., realizando 14 sesiones basada juegos reducidos de fútbol con intervención del entrenador para el grupo experimental y sin ella en el grupo control. Se mide la condición física con los test Squat Jump (SJ), Counter Movement Jump (CMJ), Course Navette, Velocidad 30 y 10 m., Cambios de dirección (CODA), la toma de decisiones con un test de juego reducido donde se analiza el Índice de Actuación y la técnica. En la prueba de t de Student para muestras relacionadas muestran que existen diferencias significativas (p ≤0,05) en variables físicas, siendo el grupo experimental el que presenta mejoras físicas más elevadas. En las acciones técnico-tácticas defensivas el grupo experimental obtiene mejores resultados. Ambos grupos, control y experimental, mejoran en la toma de decisiones, existiendo diferencias significativas en el global. Los juegos reducidos provocan mejoras en los jugadores en todas las variables analizadas, en mayor medida en el grupo sometido a la intervención del entrenador. Por lo tanto, son adecuados para el entrenamiento en la etapa de formación de jugadores de fútbol, sirviendo para reducir la distancia que existe entre los distintos niveles de los jugadores.
ABSTRACT
The objective of the research was to compare the influence of the coach and the reduced games on physical condition, technical-tactical and decision- making under 12 players of high level of expertise, differentiating by player levels according to the coach's criteria. 12 players participate, with an average age of 10,17 (±,389), weight of 37 (±5,893) Kg. and height of 144,75 (±6,002) cm., performing 14 sessions based on reduced football games with the intervention of the trainer for the experimental group and without it in the control group. The physical condition is measured with the test Squat Jump (SJ), Counter Movement Jump (CMJ), Course Navette, Speed 30 and 10 m., Changes of direction (CODA), decision- making with a reduced game test where the performance Index and the technique are analyzed. In the Student's t test for related samples show that there are significant differences (p ≤0,05) in physical variables, being the experimental group the one that presents more elevated physical improvements. In the technical-tactical defensive actions the experimental group gets better results. Both control and experimental groups improve decision-making, there being significant differences in the global. The reduced games cause improvements in the players in all the analyzed variables, to a greater extent in the group submitted to the intervention of the coach. Therefore, they are suitable for training at the stage of training foofball players, serving to reduce the distance that exists between the different levels of the players.
... Therefore, it was possible to adjust the load whenever necessary, allowing the maintenance of the training intensity throughout the intervention. In this regard, previous studies have shown that supervised training results in higher magnitudes of adaptations when compared to non-supervised training [28]. In contrast, our study has some limitations to be considered. ...
The study aimed to compare the effect of performing the same or different exercises for a muscle group on resistance training (RT) sessions on muscle hypertrophy at different sites along muscle length. Twenty-two detrained men (23.3 ± 4.1 years) were randomly allocated to the following groups: a group that performed the same exercises in all training sessions (N-VAR = 11) or one that varied the exercises for the same muscle groups (VAR = 11). All were submitted to 3 weekly sessions for nine weeks. Muscle thickness was assessed at the proximal, middle, and distal sites of the lateral and anterior thigh, elbow flexors, and extensors by B-mode ultrasound. The VAR group significantly increased all the sites analyzed (P < 0.05). Furthermore, the proximal site of the lateral thigh showed a larger relative increase when compared to the middle site (P < 0.05). In contrast, the N-VAR group were not revealed significant improvements only for the middle site of the lateral thigh and the proximal site of the elbow flexors (P > 0.05). Our results suggest that to perform different resistance exercises can induce hypertrophy of all sites assessed in detrained young men.
... Both the physical exercises performed on specific devices and those with free weights increase the muscular strength. For beginners and those with intermediate level it is recommended to use both free weights exercises and exercises on the apparatus [28], [29]. ...
The present study aimed to verify the effects of a 12 months resistance training using the Bulgarian method by contrast (6 reps x 70% of 1RM + 6 reps x 50% of 1 RM) on handgrip strength in women with postmenopausal osteopenia/osteoporosis. Ten women with postmenopausal osteopenia/osteoporosis (over 50 years old) were distributed into two groups: exercise group (EX) (n = 5) and control group (C) (n = 5). Handgrip strength was measured before and at the end of the study using a hydraulic hand dynamometer. The exercise group (EX) showed an increase of 12% at the end of the study for the dominant hand (p = .039) and by 10.53% for the non-dominant hand (p = .041). The control group showed a decrease in handgrip strength by -2.14% for the dominant hand (p = .018) and by -3.65% for the non-dominant hand (p = .038).
... While supervised RE generally yields superior results compared to the unsupervised counterpart [33,34], both types effectively mitigate age-related SM dysfunction [34][35][36]. However, long-term benefits of traditional RE forms are usually limited by low adherence and discontinuation of training efforts [37]. ...
Old age is associated with lower physical activity levels, suboptimal protein intake, and desensitization to anabolic stimuli, predisposing for age-related muscle loss (sarcopenia). Although resistance exercise (RE) and protein supplementation partially protect against sarcopenia under controlled conditions, the efficacy of home-based, unsupervised RE (HBRE) and multi-ingredient supplementation (MIS) is largely unknown. In this randomized, placebo-controlled and double-blind trial, we examined the effects of HBRE/MIS on muscle mass, strength, and function in free-living, older men. Thirty-two sedentary men underwent twelve weeks of home-based resistance band training (3 d/week), in combination with daily intake of a novel five-nutrient supplement (‘Muscle5’; M5, n = 16, 77.4 ± 2.8 y) containing whey, micellar casein, creatine, vitamin D, and omega-3 fatty acids, or an isocaloric/isonitrogenous placebo (PLA; n = 16, 74.4 ± 1.3 y), containing collagen and sunflower oil. Appendicular and total lean mass (ASM; +3%, TLM; +2%), lean mass to fat ratios (ASM/% body fat; +6%, TLM/% body fat; +5%), maximal strength (grip; +8%, leg press; +17%), and function (5-Times Sit-to-Stand time; −9%) were significantly improved in the M5 group following HBRE/MIS therapy (pre vs. post tests; p < 0.05). Fast-twitch muscle fiber cross-sectional areas of the quadriceps muscle were also significantly increased in the M5 group post intervention (Type IIa; +30.9%, Type IIx, +28.5%, p < 0.05). Sub-group analysis indicated even greater gains in total lean mass in sarcopenic individuals following HBRE/MIS therapy (TLM; +1.65 kg/+3.4%, p < 0.05). We conclude that the Muscle5 supplement is a safe, well-tolerated, and effective complement to low-intensity, home-based resistance exercise and improves lean mass, strength, and overall muscle quality in old age.
Meta-analysis, Resistance training, Dose-response.
PurposeThis longitudinal study investigated the potential enhancement of one physical and nine performance variables of New Zealand Rugby-Otago Rugby Football Union Academy college-age women student-athletes (NZORFUSA) using in-person- and non-video online-training (online) supervision.Methods
Recruited NZORFUSA followed a periodised training protocols over 70-weeks. During weeks 1–35 and weeks 53–70 (in-season), the NZORFUSA received 25-h of in-person supervision, participated in 15-h of team practice and game play each week. Over weeks 36–52 (off-season), due to the NZORFUSA returning home over the college summer break, NZORFUSA received online supervision. Performance assessments occurred on weeks 1, 31, 53 and 70. During each testing session, body weight, acceleration, anaerobic endurance, lower-body power, speed, and upper-body strength performance data were collected. Data from weeks 1–70 are presented in this paper; weeks 1–31 and 1–53 data were previously published.ResultsOver 70-weeks of in-person-, online-, and again in-person supervision, mean data showed a decrease in body weight [effect size, Cohen's d = 0.12, trivial; 95% confidence interval (CI): 29.4–127.7] and showed improvements in performance variables (large effect size, d = 1.49–4.33), including lower-body power (CI: 39.9–47.5), upper-body bench press strength (CI: 29.7–132.3) and anaerobic endurance; for the latter performance variable, to complete the 40 m repeat sprints needs less effort (CI: 81.3–95.5) with concurrent lower fatigue level being achieved (CI: 8.08–9.77).Conclusion
Physical and performance enhancement for Academy women student-athletes with in-person, online, and again in-person supervision over 70-weeks is attainable. Future longitudinal research is needed to assist performance enhancement for this cohort.
Background The COVID-19 pandemic has caused physical, psychological, and functional complications in society, with particular impacts on positive cases. Reduced quality of life (QOL) and sleep quality are among the many problems experienced by COVID-19 patients. Hence, exercise rehabilitation gains further importance after people are afflicted with COVID-19. This study aimed to analyze the effects of resistance training on the QOL and sleep quality in untrained men with a history of COVID-19.
Methods Based on inclusion and exclusion criteria, purposive sampling was employed to select 34 individuals who were willing to participate in the study. They were then randomly assigned to a resistance training group and a control group (n=17 per group). In order to evaluate the pretest scores of sleep quality and those of QOL, the participants were asked to complete the Pittsburgh Sleep Quality Index (PSQI) and the Short Form 36 Health Survey Questionnaire (SF-36), respectively. Subsequently, the training group received eight weeks of resistance training held three sessions weekly. The participants re-completed the foregoing questionnaires when all training sessions were over to determine their posttest scores. The resultant data were then analyzed in SPSS 27.
Results The research findings indicated significant differences between the resistance training group and the control group regarding the QOL and sleep quality after eight weeks of resistance training (P ≤ 0.05).
Conclusions Given the findings of the current study, one can conclude that resistance training has positive effects on the QOL and sleep quality in untrained men with a history of COVID-19. Hence, resistance training can probably be recommended to rehabilitate patients with COVID-19.
Trial registration number IRCT20230221057480N1, 2023-03-04, retrospectively registered.
Objective:
Individual unsupervised home-based exercise programs can enhance muscle strength, physical function, gait, and balance in older adults. However, the effectiveness of such programs may be limited by the lack of supervision. This study aims to verify the effectiveness of individual unsupervised home-based programs, compare the effects of individual unsupervised home-based to supervised programs, and verify the influence of supervision over individual unsupervised home-based programs on the physical function of older adults.
Methods:
A systematic literature search was performed in four electronic databases, and the trials involved randomized controlled comparing the home-based programs to supervised, control groups, or home-based + supervised evaluating the muscle strength, physical function, gait, and balance in older adults.
Results:
Eleven studies met the inclusion criteria. The meta-analysis revealed no differences between home-based program versus supervised program in gait, mobility, and balance, revealing a trend of significance to supervised program on strength (standardized mean difference [SMD] = 0.27, p = .05). The analysis revealed effects in mobility (SMD = 0.40, p = .003), balance (SMD = 0.58, p = .0002), and muscle strength (SMD = 0.36, p = .02) favoring home-based program versus control group. Significant effects between home-based program versus home-based + supervised program were observed in balance (SMD = 0.74, p = .002) and muscle strength (SMD = 0.58, p = .01) in favor of home-based + supervised program.
Conclusion:
Home-based programs effectively improve older adults' physical function compared with control groups. However, supervised programs were more effective for muscle strength.
Background: The current literature on the chronic effects of static stretching (SS) exercises on muscle strength and power is unclear and controversial.
Objective: To examine the chronic effects of SS exercises on muscle strength and power as well as flexibility in healthy individuals across the lifespan.
Design: Systematic review with meta-analysis of (randomised) controlled trials.
Data sources: A systematic literature search was conducted in the databases PubMed, Web of Science, Cochrane Library, and SPORTDiscus up to May 2022.
Eligibility criteria for selecting studies: We included studies that investigated the chronic effects of SS exercises on at least one muscle strength and power outcome compared to an active/passive control group or the contralateral leg (using between- or within-study designs) in healthy individuals, irrespective of age, sex, and training status.
Results: The main findings of 41 studies indicated trivial-to-small positive effects of chronic SS exercises on muscle strength (standardised mean difference [SMD]=0.21, [95% CI=0.10 to 0.33], p=0.001) and power (SMD=0.18, [95% CI=0.12 to 0.25], p<0.001). For flexibility, moderate-to-large increases were observed (SMD=0.96, [95% CI=0.69 to 1.23], p<0.001). Subgroup analyses, taking the participants' training status into account, revealed a larger muscle strength improvement for sedentary (SMD=0.58, p<0.001) compared to recreationally active participants (SMD=0.16, p=0.029). Additionally, larger flexibility gains were observed following passive (SMD=0.97, p<0.001) compared to active SS exercises (SMD=0.59, p=0.001). SS’s chronic effects on muscle strength were moderated by the proportion of females in the sample (β=0.004, p=0.042), with higher proportions experiencing larger gains. Other moderating variables included mean age (β=0.011, p<0.001), with older individuals showing larger muscle strength gains, and the number of repetitions per stretching exercise and session (β=0.023, p=0.004 and β=0.013, p=0.008, respectively), with more repetitions associated with larger muscle strength improvements. Muscle power was also moderated by mean age (β=0.006, p=0.007) with larger gains in older individuals. The meta-regression analysis indicated larger flexibility gains with more repetitions per session (β=0.094, p=0.016), more time under stretching per session (β=0.090, p=0.026), and more total time under stretching (β=0.078, p=0.034).
Conclusion: The main findings indicated that chronic SS exercises have the potential to improve muscle strength and power. Such improvements appear to benefit sedentary more than recreationally active participants. Likewise, chronic SS exercises result in a marked enhancement in flexibility with larger effects of passive, as compared to active, SS. Results of the meta-regression analysis for muscle strength indicated larger benefits of chronic SS exercises in samples with higher proportions of females, older participants, and higher number of repetitions per stretching exercise and session. For muscle power, results suggested larger gains for older participants. Regarding flexibility, findings indicated larger benefits following a higher number of repetitions per exercise and longer time under stretching per session as well as longer total time under stretching.
To monitor the strength exercises, the idea is to capture a template signal while instructing users to perform the movements correctly according to their ability and state of health. This template is used in an online template-matching algorithm based on DTW that was evaluated using the join angles and segment positions estimated by the pose estimation approach, while users performed the squat exercise. This method is optimized using a motion primitive detection technique and feature extraction. The results show that compared to other optimization approaches, the proposed method led to a lower execution time while maintaining a good accuracy. This effectively provides a measure for RM, which is one of the critical factors in monitoring strength exercises.KeywordsInertial sensorsMotion trackingOnline template matchingDynamic time warpingStrength exercise monitoring
The study used a mixed-methods approach to examine how the presence of coaches influenced male academy rugby league players’ performance during physical performance testing. Fifteen male rugby players completed two trials of 20 m sprint, countermovement jump and prone Yo-Yo test; one with only the sport scientist present and a second where the sport scientist conducted the battery with both the club's lead strength and conditioning coach, academy manager, and the first team assistant and head coach present. Players and coaches then completed one-to-one semi-structured interviews to explore their beliefs, attitudes and opinions towards physical performance testing. In all tests, the players’ performance was better when the coaches were present compared to when tests were conducted by the sport scientist alone. Interviews revealed performance testing was used by coaches to exercise their power over players to socialise them into the desired culture. Players’ own power was evident through additional effort during testing when coaches were present. Practitioners should ensure consistency in the presence of significant observers during performance testing of male rugby players to minimise their influence on test outcome.
Type 2 diabetes mellitus (T2DM) accounts for approximately 90% of diabetes cases globally. Regular physical activity is regarded as one of the key components in T2DM management. Aerobic exercise was traditionally recommended; however, there is a growing body of research examining the independent effect of resistance training (RT) on glycemic control. This systematic review and meta-analysis aimed to conduct an update on the effects of RT on glycosylated hemoglobin (HbA1c) in adults with T2DM and examine the moderating effects of training effect (ie, muscular strength improvements), risk of bias and intervention duration. Peer-reviewed articles published in English were searched across MEDLINE, Embase, CINAHL, Scopus and SPORTDiscus from database inception until January 19, 2021. Each online database was systematically searched for randomized controlled trials reporting on the effects of RT on HbA1c in individuals with T2DM. Twenty studies (n=1172) were included in the meta-analysis. RT significantly reduced HbA1c compared with controls (weighted mean difference=−0.39, 95% CI −0.60 to −0.18, p<0.001, I ² =69.20). Training effect significantly (p<0.05) moderated the results, with larger improvements in muscular strength leading to greater reductions in HbA1c (β=−0.99, CI −1.97 to −0.01). Intervention duration and risk of bias did not significantly moderate the effects. As a secondary analysis, this study found no significant differences in HbA1c when comparing RT and aerobic training (p=0.42). This study demonstrates that RT is an effective strategy to decrease HbA1c in individuals with T2DM. Importantly, RT interventions that had a larger training effect appeared more effective in reducing HbA1c, compared with interventions producing medium and small effects.
PROSPERO registration number CRD42020134046.
A prescrição, execução e controle de programas de treinamento são algumas das principais funções do personal trainer (PT). O objetivo do presente estudo foi revisar os efeitos de programas supervisionados versus não supervisionados por PT no treinamento de força. Diante dos desfechos funcionais e morfológicos dos estudos analisados, a atuação do personal trainer na prescrição e execução dos programas de treinamento parece trazer benefícios superiores a programas não orientados. Dessa forma, a atuação do PT, devido a um maior controle das variáveis do treinamento, orientação correta do movimento, além do reforço psicológico no incentivo da tarefa estabelecida, deve ser estimulada a fim de potencializar os benefícios comumente relacionados à prática do exercício de força.
Objectives
Multiple sclerosis (MS), the most common chronic and progressive neurological condition of the central nervous system, affects 26,000 Australian adults. Exercise training has beneficial effects on MS-related impairments including reduced muscular strength, poor aerobic capacity and impaired mobility, and in consequence can improve quality of life. This Position Statement provides evidence-based recommendations for exercise prescription and delivery of exercise training for people with MS with mild to moderate disability.
Design and Methods
Synthesis of published works within the field of exercise training in MS.
Results
Exercise provides many benefits to people with MS. There is strong evidence that resistance and aerobic training, performed 2 to 3 times per week at a moderate intensity, are safe and can improve muscle strength, cardiorespiratory fitness, balance, fatigue, functional capacity, mobility and quality of life in people with MS with mild to moderate disability (Expanded Disease Severity Scale (EDSS) ≤ 6.5). However, the evidence for those with severe disability (EDSS > 6.5) is less clear. The effects of exercise on MS pathogenesis, central nervous structures and other outcomes such as depression and cognitive impairment, have not been adequately investigated. Effective exercise interventions to improve balance, joint contractures and reduce falls in people with MS are also urgently needed as well as investigations of long-term (≥1 year) effects of exercise training.
Conclusions
Resistance and aerobic training exercises are effective to alleviate some characteristic signs and symptoms in MS and should be supplemented by balance exercise to prevent falls. Exercise training programs should be prescribed and delivered by qualified exercise professionals. It is important to recognise and accommodate exercise-associated complications such as fatigue and heat sensitivity.
Bakgrunn: Regelmessig styrketrening gir gunstige helseeffekter for personer med kronisk obstruktiv lungesykdom (KOLS), og er derfor en naturlig del av lungerehabiliteringen. Pasienters opplevelse av slik trening er imidlertid lite studert. Hensikten med denne kvalitative studien var å kartlegge erfaringer med styrketrening hos deltakere i The Granheim COPD Study.
Materiale og metode: Åtte av 24 prosjektdeltakere med KOLS (kvinner/menn, n=3/n=5; KOLS grad II/III, n=4/n=4; alder, 64-79 år) gjennomførte semistrukturerte, kvalitative intervjuer i den femte av totalt 13 uker med styrketrening.
Funn: Samlet for alle prosjektdeltakerne med KOLS var treningsadherensen høy (97%) og frafallet lavt (n=2 av 22) under treningsperioden. Informantene som gjennomførte kvalitative intervjuer opplevde nokså høy og stigende grad av motivasjon for å trene under intervensjonen. Dette var knyttet til tett personlig oppfølging fra treningskyndig personell og opplevelse av trygghet under treningsøktene, samt økt mestringsfølelse og økt kompetanse.
Fortolkning: Personlig veiledning fra treningskyndig personell var en avgjørende faktor for å øke treningsmotivasjonen blant studiedeltakerne. Individuell tilrettelegging og oppfølging ser derfor ut til å være en forutsetning for å oppnå gode aktivitetsvaner hos personer med KOLS.
Nøkkelord: atferdsendring, kvalitativ forskning, lungerehabilitering, personlig treningsveiledning, treningsmotivasjon.
https://fysioterapeuten.no/fagfellevurdert-fysioterapi-kols/styrketrening-ved-kronisk-obstruktiv-lungesykdom-erfaringer-fra-the-granheim-copd-study-en-kvalitativ-analyse-av-motivasjonsfaktorer/134035
Background:
This study examined the effect of a personal trainer's sex on self-efficacy and fitness in woman clients.
Methods:
Women (n: 28; mean ± SD; age, 41.6 ± 15.0 yrs.; height, 153.49 ± 28.11cm; BMI, 25.9 ± 6.4 kg•m-2) completed a perceptual scale of self-efficacy (BARSE) and fitness tests before and after a training program. Trainers (men and women) met one-on-one with the volunteers on a biweekly basis for 8 weeks. Univariate analyses of change scores and repeated measures analysis of variance with Fisher's LSD pairwise comparisons tested changes in dependent variables by trainer sex.
Results:
Significant increases were seen in (mean ± SE; change for men trainers; change for woman trainers): self-efficacy (7.3 ± 3.4; 7.3 ± 2.7%); leg press strength (18.2 ± 3.7; 16.4 ± 3.3 kg); seated row (6.1 ± 1.5; 5.3 ± 1.3 kg); muscular endurance in 60° flexion hold (20.5 ± 5.8; 24.8 ± 5.0 sec) and wall-sit (19.9 ± 6.4; 33.5 ± 5.8 sec); but not flexibility (V-sit, 7.11 ± 5.51; 4.23 ± 4.50 cm). Chest press strength significantly increased for women trainers only (2.7 ± 2.2; 5.3 ± 1.8 kg). Despite this, there were no significant differences for any variable in the change from pre-to-post based on the sex of the trainer.
Conclusions:
Both men and woman-led training was effective for increasing markers of self-efficacy and fitness in woman clients.
One of the biggest problems of modern humans is a passive lifestyle and a lack of physical activity. Physical inactivity is more prevalent among women than men, and participation in physical activity decreases as women age. Those women who are physically active usually take part in a group or personal fitness exercise programmes. The purpose of the present study was to investigate the differences in motor skills between the two groups of women who attend group and personal fitness programmes. The results of the present study revealed that there were significant differences between the two groups of participants in five out of seven tested variables. Women from the personal fitness programme had better results in strength tests standing broad jump, sit-ups, and bent arm hang, while the women from the group fitness programme were more successful in the flamingo balance test and the shuttle run 10x5 m agility test. Finally, no significant differences were observed between the groups in plate tapping and sit-and-reach (p = 0.43) tests. The presented findings suggest that participation in both the personal and group fitness exercise programmes has its advantages for motor skill improvement and that all clients should choose in line with their personal goals.
Purpose: Functional dysfunction has been reported as one of the most important consequences of functional ankle instability injury. One of the newest tools used to rehabilitate musculoskeletal injuries is suspension training with TRX)Total Body Resistance Exercise(. However, so far, its effect on the various functional factors in athletes with functional ankle instability has not been determined. Therefore, the purpose of this study was to investigate the effect of 6 weeks of suspension training with TRX on the performance scores of athletes with functional ankle instability. Methods: 30 male athletes with functional ankle instability were selected and then randomly assigned into the control and training groups. The subjects were selected by inclusion and exclusion criteria. Subjects' performance was assessed by side hop test, figure 8 test, and three single-leg hop test. The training group performed 18 training sessions of 45 minutes during 6 weeks. During 6 weeks, control group were asked to not perform any special exercise. Then, the post-test was performed in both groups. In order to compare the scores of functional tests between two groups, paired t-test and covariance analysis were used. Significant level was considered as p≤0.05 in all statistical analyzes. Results: The results of statistical tests showed that there is a significant difference between the mean scores of each of the three side hop test (p=0.001) figure 8 test (p=0.001), and three single-leg hop tests (p=0.001) between the two groups in the post-test. Therefore, that subjects of the TRX training group had better performance in all three tests than those in the control group. Conclusion: Since the results of this study showed that performing TRX suspension training can improve the performance of athletes in side-hop test, figure 8 test and triple hop test, therefore it recommended that all sport trainers use the exercises used in this study to improve the performance of athletes with functional ankle instability.
This study examined the effects of different volumes of resistance training on muscle size and function over a 10-wk period. Low volume = 3 sets per muscle group per week; moderate = 6 sets; high = 12 sets. Twenty-seven men with 1-4 yrs weight training experience were randomly assigned to the different training volumes and trained 4 days a week. A periodized routine was used; exercises, training intensity, and number of training days were the same for each group. The only variation between conditions was the number of sets per exercise. Pre and post measurements assessed muscular size via ultrasound; strength via maximum squat and bench press; and power via vertical jump and bench press throw. Urinary concentrations of test-osterone and cortisol were also analyzed to assess the responses to training conditions. All 3 training volumes significantly (p < 0.05) increased muscle size, strength, and upper body power, with no significant between-group differences. There were no significant changes in hormonal concentrations. The results support the use of low volume training for muscular development over a 10-wk period.
(C) 1997 National Strength and Conditioning Association
Thirty-five healthy men were matched and randomly assigned to one of four training groups that performed high-intensity strength and endurance training (C; n = 9), upper body only high-intensity strength and endurance training (UC; n = 9), high-intensity endurance training (E; n = 8), or high-intensity strength training (ST; n = 9). The C and ST groups significantly increased one-repetition maximum strength for all exercises (P < 0.05). Only the C, UC, and E groups demonstrated significant increases in treadmill maximal oxygen consumption. The ST group showed significant increases in power output. Hormonal responses to treadmill exercise demonstrated a differential response to the different training programs, indicating that the underlying physiological milieu differed with the training program. Significant changes in muscle fiber areas were as follows: types I, IIa, and IIc increased in the ST group; types I and IIc decreased in the E group; type IIa increased in the C group; and there were no changes in the UC group. Significant shifts in percentage from type IIb to type IIa were observed in all training groups, with the greatest shift in the groups in which resistance trained the thigh musculature. This investigation indicates that the combination of strength and endurance training results in an attenuation of the performance improvements and physiological adaptations typical of single-mode training.
1. Skinfold thickness, body circumferences and body density were measured in samples of 308 and ninety-five adult men ranging in age from 18 to 61 years.
2. Using the sample of 308 men, multiple regression equations were calculated to estimate body density using either the quadratic or log form of the sum of skinfolds, in combination with age, waist and forearm circumference.
3. The multiple correlations for the equations exceeded 0.90 with standard errors of approximately ±0.0073 g/ml.
4. The regression equations were cross validated on the second sample of ninety-five men. The correlations between predicted and laboratory-determined body density exceeded 0.90 with standard errors of approximately 0.0077 g/ml.
5. The regression equations were shown to be valid for adult men varying in age and fatness.
To examine endogenous anabolic hormonal responses to two different types of heavy resistance exercise protocols (HREPs), eight male and eight female subjects performed two randomly assigned protocols (i.e. P-1 and P-2) on separate days. Each protocol consisted of eight identically ordered exercises carefully designed to control for load, rest period length, and total work (J) effects. P-1 utilized a 5 RM load, 3-min rest periods and had lower total work than P-2. P-2 utilized a 10 RM load, 1-min rest periods and had a higher total work than P-1. Whole blood lactate and serum glucose, human growth hormone (hGH), testosterone (T), and somatomedin-C [SM-C] (i.e. insulin-like growth factor 1, IGF-1) were determined pre-exercise, mid-exercise (i.e. after 4 of the 8 exercises), and at 0, 5, 15, 30, and 60 min post-exercise. Males demonstrated significant (p less than 0.05) increases above rest in serum T values, and all serum concentrations were greater than corresponding female values. Growth hormone increases in both males and females following the P-2 HREP were significantly greater at all time points than corresponding P-1 values. Females exhibited significantly higher pre-exercise hGH levels compared to males. The P-1 exercise protocol did not result in any hGH increases in females. SM-C demonstrated random significant increases above rest in both males and females in response to both HREPs.(ABSTRACT TRUNCATED AT 250 WORDS)
An 8-wk progressive resistance training program for the lower extremity was performed twice a week to investigate the time course for skeletal muscle adaptations in men and women. Maximal dynamic strength was tested biweekly. Muscle biopsies were extracted at the beginning and every 2 wk of the study from resistance-trained and from nontrained (control) subjects. The muscle samples were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain content. In addition, fasting blood samples were measured for resting serum levels of testosterone, cortisol, and growth hormone. With the exception of the leg press for women (after 2 wk of training) and leg extension for men (after 6 wk of training), absolute and relative maximal dynamic strength was significantly increased after 4 wk of training for all three exercises (squat, leg press, and leg extension) in both sexes. Resistance training also caused a significant decrease in the percentage of type IIb fibers after 2 wk in women and 4 wk in men, an increase in the resting levels of serum testosterone after 4 wk in men, and a decrease in cortisol after 6 wk in men. No significant changes occurred over time for any of the other measured parameters for either sex. These data suggest that skeletal muscle adaptations that may contribute to strength gains of the lower extremity are similar for men and women during the early phase of resistance training and, with the exception of changes in the fast fiber type composition, that they occur gradually.
This abridged version of the "Anthropometric Standardisation Reference Manual" contains the heart of the original manual - complete procedures for 45 anthropometric measurements. Its style enables it to be used as a supplemental text for courses in fitness assessment and exercise prescription, kinanthropometry, body composition, nutrition, and exercise physiology. It can also be used as a reference for exercise scientists. For each of the 45 measurements included in this abridged edition, readers will find complete information on the recommended technique for making the measurement, the purpose and uses for the measurement, the literature on which the measurement technique is based, and the reliability of the measurement.
Information concerning frequency of training for resistance trained individuals is relatively unknown. Problems in designing training programs for student athletes are frequently encountered due to differential time constraints placed upon them. The purpose of this study was to examine the effects of self-selection of resistance training frequency on muscular strength. Sixty-one members of an NCAA. Division IAA football team participated in a 10-week winter conditioning program. Each subject was given the option of choosing from a three-day (3d, n=12) four-day (4d, n=15), five-day (5d, n=23) or six-day (6d, n=ll) per week resistance training program. In addition to the strength training, the subjects participated in a football conditioning program twice a week. Testing was conducted before and after the 10-week training program. Field tests common to football off-season conditioning programs were utilized to evaluate strength (1 RM squat and bench press), speed (40-yard sprint), endurance (two-mile run), vertical jump and anthropometric measurements. Posttests revealed significant changes for the 3d group in decreased time for the two-mile run (2mi), decreased sum of skinfolds (SF) and an increased chest girth (CH). The 4d program revealed significant decreases in body weight, 2mi, SF, and increases in 1 RM squat, CH and thigh girths (TH). The 5d group significantly decreased 2mi, and SF, and increased both 1 RM squat and bench press and CH and TH. The 6d group revealed significant decreases in 2mi, and SF, and an increase in 1 RM squat. Of the total variables measured, 4d and 5d frequency groups revealed the greatest amount of improvement. In conclusion, when resistance training frequency is self-selected by athletes (i.e., college football players) it appears that four or five days per week are the optimal choices for developing strength, endurance and muscle mass.
(C) 1990 National Strength and Conditioning Association
This study examined the effects of manipulating volume and intensity on strength and power in experienced male athletes. Subjects (N = 22) were tested for maximum strength in the squat and bench press lifts, vertical jump (VJ), lean body mass (LBM), and neural activation levels (IEMG). They trained 3 days a week for 12 weeks according to a linear periodization model (n = 8), an undulating periodization model (n = 5), or a nonperiodized control model (n = 9). Training volume and relative intensity were equated for all groups. Maximal squat, bench press, and LBM all improved significantly in each group, and changes in maximal strength correlated significantly with changes in LBM. IEMG levels were generally unchanged and did not correlate with changes in strength. The VJ increased significantly through training, but there were no differences between groups. Changes in VJ were not significantly correlated with changes in squat, LBM, or IEMG levels. The results indicate that in short-term training using previously trained subjects, no differences in maximal strength are seen when training volume and relative intensity are equated.
(C) 1994 National Strength and Conditioning Association
The present investigation compared the effects of three selected mesocycle-length weight training programs using partially equated volumes on upper and lower body strength. Ninety-two previously weight-trained males were tested at five intervals (T1 through T5) on freeweight bench press and parallel back squat strength before, during, and after 16 weeks of training. Groups 1 and 2 trained with programs consisting of 5x10-RM at 78.9% of 1-RM and 6x8-RM at 83.3% of 1-RM, respectively, while keeping the amount of sets, repetitions, and training resistance (relative intensity) constant. Group 3 trained with a periodization program involving 4 weeks of 5x10-RM at 78.9% of 1-RM, 4 weeks of 6x8-RM with 83.3% of 1-RM, 4 weeks of 3x6-RM with 87.6% of 1-RM, and 4 weeks of 3x4-RM with 92.4% of 1-RM. Group 4 served as a non-weight-training control group. A 4x5 (Group x Test) MANOVA with repeated measures on test revealed that pretest normalized bench press and squat strength values were statistically equal when the study began. For the bench press at T2, results revealed that Groups 1, 2, and 3 were significantly different from Group 4 but not from each other. At T3, T4, and T5, Group 3 demonstrated significantly different strength levels in the bench press from Groups 1, 2, and 4. Groups 1 and 2 were not significantly different from Group 4. For the squat exercise at T2, T3, and T4, Groups 2 and 3 were significantly different from Groups 1 and 2 but not from each other. At T5, Group 3 was significantly different from Groups 1, 2, and 4. Group 2 was significantly different from Groups 1 and 4, and Group 1 was only significantly different from Group 4. It was concluded that a mesocycle-length weight training program. incorporating periodization is superior in eliciting upper and lower body strength gains when compared to programs with partially equated volumes.
(C) 1993 National Strength and Conditioning Association
The purpose of this series of investigations was to gain insight on resistance training in American football and address some of the myths. Many theories about resistance training have been proposed, yet there has been little if any research on some of these training philosophies. This series of studies represents an accumulation of data that helped to formulate a training approach. Rather than having a training philosophy, it might be more productive to have a training approach based on facts and critical monitoring of test variables representative of the physical development possible through strength and conditioning programs. It was demonstrated that football players are capable of multiple maximal efforts in resistance training and that the length of the rest period was a determining factor. In general, multiple sets and various periodized training programs were superior to single-set programs in the rate and magnitude of improvements in body composition, strength, local muscular endurance, and power. Such data indicate that for building programs in previously trained football players, multiple-set programs that provide variation are more appropriate.
(C) 1997 National Strength and Conditioning Association
The effects of different methods of weight training on strength and short-term work capacity are not clearly understood. This study describes the leg and hip maximum strength and endurance responses to two different weight training methods. Ninety healthy college males were divided into two training groups. Group 1 (G1, n = 46) used a "periodized" approach of moving from high-volume, low-intensity to low-volume, high-intensity exercise across the training program (11 weeks). Group 2 (G2, n = 44) used a 3 x 6 RM. Changes in maximum strength were measured with a 1 RM parallel squat. Power capacity was measured by incremental cycle ergometer exercise. A subset of each group (G1 = 17; G2 = 14) was used in the estimation of short-term power capacity. The results show that weight training can significantly (p<.01) increase maximum strength and short-term power capacity (endurance) simultaneously and that the periodized group (G1) produced superior results.
(C) 1988 National Strength and Conditioning Association
This study examined the effects of a single set of weight training exercise to failure and 2 multiple-set protocols (not to failure) on the 1-RM parallel squat. Forty-three men were randomly assigned to 1 of 3 weight training protocols emphasizing leg and hip strength: SS = single set to failure of 8-12 reps; MS = 3 x 10 reps; MSV = multiple-set program using a varied set and rep scheme. Relative intensity (% initial 1-RM), intensity (average mass lifted), and volume load (repetitions x mass) differed between groups over 14 weeks. Body mass, body composition, and the 1-RM parallel squat were assessed at baseline and at Weeks 5 and 14. Results showed no significant changes in body mass or body composition. The 1-RM squat increased significantly in all groups. Differences in 1-RM between groups indicate that MS and MSV increased approximately 50% more than SS over the 14 weeks. Results suggest that multiple sets not performed to failure produce superior gains in the 1-RM squat.
(C) 1997 National Strength and Conditioning Association
The effects of a 24-weeks' progressive training of neuromuscular performance capacity on maximal strength and on hormone balance were investigated periodically in 21 male subjects during the course of the training and during a subsequent detraining period of 12 weeks. Great increases in maximal strength were noted during the first 20 weeks, followed by a plateau phase during the last 4 weeks of training. Testosterone/cortisol ratio increased during training. During the last 4 weeks of training changes in maximal strength correlated with the changes in testosterone/cortisol (P<0.01) and testosterone/SHBG (P<0.05) ratios. During detraining, correlative decreases were found between maximal strength and testosterone/cortisol ratio (P<0.05) as well as between the maximal strength and testosterone/SHBG ratio (P<0.05). No statistically significant changes were observed in the levels of serum estradiol, lutropin (LH), follitropin (FSH), prolactin, and somatotropin. The results suggest the importance of the balance between androgenic-anabolic activity and catabolizing effects of glucocorticoids during the course of vigorous strength training.
Nine different weight training programs were compared to determine which were more effective in improving strength. The experiment was conducted with the bench press lift for a period of 12 weeks with approximately 20 subjects in each weight training program. Subjects were tested for the 1 RM on the bench press lift at the beginning of training and at three-week intervals. Training took place three times weekly with the variations in programs involving one, two, and three sets, and two, six, and ten repetitions per set. The results showed that three sets and six repetitions per set were best for improving strength.
The time course of strength gain with respect to the contributions of neural factors and hypertrophy was studied in seven young males and eight females during the course of an 8 week regimen of isotonic strength training. The results indicated that neural factors accounted for the larger proportion of the initial strength increment and thereafter both neural factors and hypertrophy took part in the further increase in strength, with hypertrophy becoming the dominant factor after the first 3 to 5 weeks. Our data regarding the untrained contralateral arm flexors provide further support for the concept of cross education. It was suggested that the nature of this cross education effect may entirely rest on the neural factors presumably acting at various levels of the nervous system which could result in increasing the maximal level of muscle activation.
The inability of the exercises presently used during space-flight to maintain muscle strength and mass may reflect the absence of eccentric (ecc) muscle actions. This study examined the importance of ecc actions in performance adaptations to resistance training. Middle-aged males performed 4-5 sets of 6-12 repetitions (rep) per set of the leg press and leg extension exercises 2 d each week for 19 weeks. Group CON/ECC (n = 9) performed each rep with concentric (con) and ecc actions, group CON (n = 8) with only con actions. Group CON/CON (n = 10) performed twice as many sets with only con actions. The resistance per set was selected to induce failure within the prescribed number of rep. Eight subjects did not train and served as controls. The increase in the three rep maximum (3RM) after training, in general, showed a hierarchy such that CON/ECC greater than CON/CON greater than CON. The differences (p less than 0.05) were: leg press 3RM with con and ecc actions, CON/ECC greater than CON/CON greater than CON (26 greater than 15 greater than 8%); leg press 3RM with only con actions, CON/ECC or CON/CON greater than CON (22 or 18 greater than 14%); and leg extension 3RM with con and ecc actions, CON/ECC greater than CON (29 greater than 16%). These differences (p less than 0.05) were still evident after 1 month of de-training. The results indicate that omission of ecc actions from resistance training compromises increases in strength, probably because intensity is not optimal.(ABSTRACT TRUNCATED AT 250 WORDS)
The muscle enzymatic changes subsequent to 6 months of strength training followed by 3 months of detraining were examined in 21 physically active men. They were assigned either to a heavy-resistance (HR) or an explosive strength (EX) training program. Muscle biopsies were obtained from m. vastus lateralis for the assessment of activities of the enzymes hexokinase (HK), myofibrillar ATPase (ATPase), citrate synthase (CS), phosphofructokinase (PFK), lactate dehydrogenase (LDH), myokinase (MK) and creatine kinase (CK). The activities were measured on freeze-dried tissue samples using fluorometrical assays. Both groups displayed increased (P less than 0.01-0.001) fast-twitch (FT) fiber area consequent to training with no concomitant hypertrophy of slow-twitch (ST) fiber area. Mean fiber area increased by 16% (P less than 0.001) in HR and 9% (NS) in EX. Following detraining, mean fiber area returned to pretraining value only in EX. HK decreased in both groups (P less than 0.01-0.001) and CK decreased in HR (P less than 0.05). When the two groups were treated together, all enzymes, except for LDH, decreased their activity (P less than 0.05-0.001). It is concluded that 6 months of strength training performed either as heavy-resistance or explosive training is not associated with any increased activities of enzymes reflecting phosphagen, glycolytic, or oxidative metabolism. Instead, the present results suggest that exercise-induced hypertrophy is accompanied by attenuation of certain enzyme activities of importance for ATP regeneration.
Resistance training results in a wide spectrum of adaptations in various physiological systems. Increases in muscle size and strength, changes in body composition, neuroendocrine function and cardiovascular responses have been observed following resistance training. Additionally, resistance training may be an effective means by which the incidence of sports injuries can be reduced.
The physiological alterations induced by resistance training appear to be specific to the number of sets and repetitions and exercises performed. Thus, special attention is required when developing the exercise prescription for resistance training.
Heavy-resistance exercise utilizing very short rest periods is commonly used by body builders to prepare for competition. The purpose of this study was to compare the acute responses of this type of heavy-resistance exercise protocol in competitive body builders (BB) and power lifters (PL). Nine male BB and eight PL were matched for age, size and experience. A ten-station heavy-resistance exercise protocol was used. Each subject performed three sets of 10 repetition maximum (RM) with 10-s rest between sets and alternated 30-s and 60-s rest periods between exercises. No differences were observed in total work between the groups, but BB used a significantly (P less than 0.05) higher percentage of their 1 RM in the bench press and leg press exercises. Heart rate, ratings of perceived exertion (RPE), and lactate levels were obtained during the exercise protocol; significant (P less than 0.05) increases were observed above rest for these variables. RPE was significantly correlated with lactate levels (r = 0.84). Plasma epinephrine, norepinephrine, dopamine, cortisol, and lactate levels significantly increased from pre- to 5 min post-exercise. Mean plasma volumes were reduced -16.6 (+/- 3.64)% and -20.6 (+/- 8.32)% following the exercise protocol for BB and PL, respectively. Significant (P less than 0.05) decreases in eosinophil counts were observed following exercise. No significant differences were observed between BB and PL for any of the physiologic responses measured. PL exhibited a higher incidence (100%) of clinical symptoms of dizziness and nausea compared to BB (11.1%).(ABSTRACT TRUNCATED AT 250 WORDS)
Tissue samples were obtained from vastus lateralis and deltoid muscles of physical education students (n = 12), Greco-Roman wrestlers (n = 8), flat-water kayakers (n = 9), middle- and long-distance runners (n = 9), and olympic weight and power lifters (n = 7). Histochemical stainings for myofibrillar adenosinetriphosphatase and NADH-tetrazolium reductase were applied to assess the relative distribution of fast-twitch and slow-twitch (ST) muscle fiber types and fiber size. The %ST was not different in the vastus (mean SD 48 +/- 14) and deltoid (56 +/- 13) muscles. The %ST was higher (P less than 0.001), however, in the deltoid compared with vastus muscle of kayakers. This pattern was reversed in runners (P less than 0.001). The %ST of the vastus was higher (P less than 0.001) in runners than in any of the other groups. The %ST of the deltoid muscle was higher in kayakers than in students, runners (P less than 0.001), and lifters (P less than 0.05). The mean fiber area and the area of ST fibers were greater (P less than 0.01) in the vastus than the deltoid muscle. Our data show a difference in fiber type distribution between the trained and nontrained muscles of endurance athletes. This pattern may reflect the adaptive response to long-term endurance training.
To investigate the influence of explosive type strength training on isometric force- and relaxation-time and on electromyographic and muscle fibre characteristics of human skeletal muscle, 10 male subjects went through progressive training which included primarily jumping exercises without extra load and with light extra weights three times a week for 24 weeks. Specific training-induced changes in force-time curve were observed and demonstrated by great (P less than 0.05-0.01) improvements in in parameters of fast force production and by a minor (P less than 0.05) increase in maximal force. The continuous increases in fast force production during the entire training were accompanied by and correlated with the increases (P less than 0.05) in average IEMG-time curve and with the increase (P less than 0.05) in the FT:ST muscle fibre area ratio. The percentage of FT fibres of the muscle correlated (P less than 0.05) with the improvement of average force-time curve during the training. The increase in maximal force was accompanied by significant (P less than 0.05) increases in maximum IEMGs of the trained muscles. However, the hypertrophic changes, as judged from the anthropometric and muscle fibre area data, were only slight during the training. It can be concluded that in training for fast force production considerable neural and selective muscular adaptations may occur to explain the improvement in performance, but that genetic factors may determine the ultimate potential of the trainability of this aspect of the neuromuscular performance.
Forty-seven women and twenty-six men volunteered to participate in a 10-week program of intensive weight training, with an average attendance of two days per week, 40 minutes per session. Assessments of strength, body composition and anthropometric girths, diameters and skinfolds were made at the beginning and at the conclusion of the study period. Both groups made similar relative gains in strength and absolute gains in body composition. The men were stronger than the women for all strength measures, although the women exhibited a greater leg strength when expressed relative to lean body weight. Muscular hypertrophy evident in both groups, was confined basically to the upper extremity, and was of substantially greater magnitude in the males. Correlations between absolute strength and girth size indicate a probable relationship between muscle size and strength, but hypertrophy is not a predominant consequence of increasing total body or individual muscle strength. (C)1974The American College of Sports Medicine