Muscular rate of force development (RFD) is positively influenced by resistance training. However, the effects of movement patterns and velocities of training exercises are unknown.
To determine the ...effects of velocity, the intent for fast force production, and movement pattern of training exercises on the improvement in isometric RFD from chronic resistance training.
A systematic search of electronic databases was conducted to 18 September, 2018. Meta-regression and meta-analytic methods were used to compute standardized mean differences (SMD ± 95% confidence intervals) to examine effects of movement pattern similarity (between training and test exercises; specific vs. non-specific) and movement speed (fast vs. slow vs. slow with intent for fast force production) for RFD calculated within different time intervals.
The search yielded 1443 articles, of which 54 met the inclusion criteria (59 intervention groups). Resistance training increased RFD measured to both early (e.g., 50 ms; standardized mean difference 95% CI 0.58 0.40, 0.75) and later (e.g., 200 ms; 0.39 0.25, 0.52) times from contraction onset, as well as maximum RFD (RFD
; 0.35 0.21, 0.48). However, sufficient data for sub-analyses were only available for RFD
. Significant increases relative to control groups were observed after training with high-speed (0.54 0.05, 1.03), slow-speed with intent for fast force production (0.41 0.20, 0.63), and movement pattern-specific (0.38 0.17, 0.59) exercises only. No clear effect was observed for slow-speed without intent for fast force production (0.21 0.00, 0.42, p = 0.05) or non-movement-specific (0.27 - 0.32, 0.85, p = 0.37) exercises. Meta-regression did not reveal a significant difference between sexes (p = 0.09); however, a negative trend was found in women (- 0.57 - 1.51, 0.37, p = 0.23), while a favorable effect was found in men (0.40 0.22, 0.58, p < 0.001). Study duration did not statistically influence the meta-analytic results, although the greatest RFD increases tended to occur within the first weeks of the commencement of training.
Resistance training can evoke significant increases in RFD. For maximum (peak) RFD, the use of faster movement speeds, the intention to produce rapid force irrespective of actual movement speed, and similarity between training and testing movement patterns evoke the greatest improvements. In contrast to expectation, current evidence indicates a between-sex difference in response to training; however, a lack of data in women prevents robust analysis, and this should be a target of future research. Of interest from a training program design perspective was that RFD improvements were greatest within the first weeks of training, with less ongoing improvement (or a reduction in RFD) with longer training, particularly when training velocity was slow or there was a lack of intent for fast force production.
Romero-Parra, N, Cupeiro, R, Alfaro-Magallanes, VM, Rael, B, Rubio-Arias, JA, Peinado, AB, and Benito, PJ, IronFEMME Study Group. Exercise-induced muscle damage during the menstrual cycle: A ...systematic review and meta-analysis. J Strength Cond Res 35(2): 549-561, 2021-A strenuous bout of exercise could trigger damage of muscle tissue, and it is not clear how sex hormone fluctuations occurring during the menstrual cycle (MC) affect this response. The aims of this study were to systematically search and assess studies that have evaluated exercise-induced muscle damage (EIMD) in eumenorrheic women over the MC and to perform a meta-analysis to quantify which MC phases display the muscle damage response. The guidelines of the Preferred Reported Items for Systematic Reviews and Meta-Analysis were followed. A total of 19 articles were analyzed in the quantitative synthesis. Included studies examined EIMD in at least one phase of the following MC phases: early follicular phase (EFP), late follicular phase (LFP), or midluteal phase (MLP). The meta-analysis demonstrated differences between MC phases for delayed onset muscle soreness (DOMS) and strength loss (p < 0.05), whereas no differences were observed between MC phases for creatine kinase. The maximum mean differences between pre-excercise and post-exercise for DOMS were EFP: 6.57 (4.42, 8.71), LFP: 5.37 (2.10, 8.63), and MLP: 3.08 (2.22, 3.95), whereas for strength loss were EFP: -3.46 (-4.95, -1.98), LFP: -1.63 (-2.36, -0.89), and MLP: -0.72 (-1.07, -0.36) (p < 0.001). In conclusion, this meta-analysis suggests that hormone fluctuations throughout the MC affect EIMD in terms of DOMS and strength loss. Lower training loads or longer recovery periods could be considered in the EFP, when sex hormone concentrations are lower and women may be more vulnerable to muscle damage, whereas strength conditioning loads could be enhanced in the MLP.
Cormier, P, Freitas, TT, Rubio-Arias, JÁ, and Alcaraz, PE. Complex and contrast training: Does strength and power training sequence affect performance-based adaptations in team sports? A systematic ...review and meta-analysis. J Strength Cond Res 34(5): 1461-1479, 2020-The aims of this meta-analysis were to examine the effects of 2 different strength and power training sequences (complex: CPX; and contrast: CNT, training) on performance-based adaptations in team sports {lower-body strength (1 repetition maximum 1RM), vertical jump (VJ), sprinting, and change of direction (COD) ability}, as well as identify factors potentially affecting said adaptations (i.e., athlete level, type of sport, intensity, and duration). CPX is the combination training that alternates biomechanically similar high load weight training exercises with lighter load power exercises, set for set (e.g., squats followed by countermovement jumps). CNT is the combination training where all high load strength exercises are performed at the beginning of the session and all lighter load power exercises at the end. After an electronic database search (PubMed, SPORTDiscus, and WoS), a total of 27 articles were included in the meta-analysis. The effects on outcomes were expressed as standardized mean differences (SMDs). Baseline to postintervention overall results for the studied variables: (a) 1RM: large effects for CPX (SMD = 2.01, 95% confidence interval CI 1.18-2.84) and CNT (SMD = 1.29, 95% CI 0.61-1.98); (b) VJ: large effects for CPX (SMD = 0.88, 95% CI 0.42-1.34) and medium effects for CNT (SMD = 0.55, 95% CI 0.29-0.81); (c) sprint: large effects for CPX (SMD = -0.94, 95% CI -1.33 to -0.54) and small effects for CNT (SMD = -0.27, 95% CI -0.92 to 0.39); and (d) COD: large effects for CPX (SMD = -1.17, 95% CI -1.43 to -0.90) and medium effects for CNT (SMD = -0.68, 95% CI -1.20 to -0.15). Regarding the studies that contained a control group: (a) 1RM: large effects for CPX (SMD = 1.61, 95% CI 1.12-2.10) and CNT (SMD = 1.38, 95% CI 0.30-2.46); (b) VJ: large effects for CPX (SMD = 0.85, 95% CI 0.45-1.25) and medium for CNT (SMD = 0.50, 95% CI 0.19-0.81); (c) sprint: medium effects for CPX (SMD = -0.69, 95% CI -1.02 to -0.36) and CNT (SMD = -0.51, 95% CI -0.90 to -0.11); and (d) COD: large effects for CPX (SMD = -0.83, 95% CI -1.08 to -0.59), and there were no control groups for CNT. In conclusion, both training interventions may lead to positive performance-based adaptations in team-sports with CPX interventions potentially leading to slightly greater effects.
The aim of a 12-week randomized double-blind placebo-controlled study was to assess the effect of daily supplementation with a natural extract of
L. (4 × 500 mg capsules/day; total 2 g per day) ...combined with a moderate-intensity training program (1 h session/3 times a week) on skeletal muscle fitness in adults over 50 years of age. Muscle strength assessed by isokinetic and isometric dynamometry improved significantly in the experimental (
= 23) and the placebo (
= 22) groups, but the magnitude of improvement was higher in the experimental group, with between-group differences in almost all variables, including isokinetic at 60° s
in knee extension, peak torque (
< 0.007); total work per repetition maximum (
< 0.009); isokinetic at 180°s
in knee extension, peak torque (
< 0.002); total work (
< 0.007); total work per repetition maximum (
< 0.005); average power (
< 0.027); isometric in knee extension, peak torque (
< 0.005); and average peak torque (
< 0.002). Similar findings were observed for muscle quality. Changes in quality of life (SF-36) were not found, except for improvements in the role physical (
< 0.023) and role emotional (
< 0.001) domains, likely as a result of the physical training sessions. A nutritional survey did not revealed changes in dietary habits. No adverse events were recorded. In subjects over 50 years of age, moderate-intensity strength training combined with daily supplementation for 12 weeks with a natural extract of
L. improved muscle-related variables and muscle quality. Maintaining muscle health is a key component of healthy aging.
Purpose
The aim of this study was to analyze the effect of hypoxia on metabolic and acid–base balance, blood oxygenation, electrolyte, and half-squat performance variables during high-resistance ...circuit (HRC) training.
Methods
Twelve resistance-trained subjects participated in this study. After a 6RM testing session, participants performed three randomized trials of HRC: normoxia (NORM: FiO
2
= 0.21), moderate hypoxia (MH: FiO
2
= 0.16), or high hypoxia (HH: FiO
2
= 0.13), separated by 72 h of recovery in normoxic conditions. HRC consisted of two blocks of three exercises (Block 1: bench press, deadlift and elbow flexion; Block 2: half-squat, triceps extension, and ankle extension). Each exercise was performed at 6RM. Rest periods lasted for 35 s between exercises, 3 min between sets, and 5 min between blocks. Peak and mean force and power were determined during half-squat. Metabolic, acid–base balance, blood oxygenation and electrolyte variables, arterial oxygen saturation (SaO
2
), and rating of perceived exertion (RPE) were measured following each block.
Results
During the first set, peak force and power were significantly lower in HH than MH and NORM; whereas in the second set, mean and peak force and power were significantly lower in HH than NORM. At the end of the HRC training session, blood lactate and RPE in HH were significantly higher than in MH and NORM. SaO
2
, pH, HCO
3
−
, and pO
2
values were significantly lower in all hypoxic conditions than in NORM.
Conclusion
These results indicate that simulated hypoxia during HRC exercise reduce blood oxygenation, pH, and HCO
3
−,
and increased blood lactate ultimately decreasing muscular performance.
This review aims to systematically analyze the effect of exercise on muscle MCT protein levels and mRNA expression of their respective genes, considering exercise intensity, and duration ...(single‐exercise session and training program) in humans and rodents, to observe whether both models offer aligned results. The review also aims to report methodological aspects that need to be improved in future studies. A systematic search was conducted in the PubMed and Web of Science databases, and the Preferred Reporting Items for Systematic review and Meta‐Analyses (PRISMA) checklist was followed. After applying inclusion and exclusion criteria, 41 studies were included and evaluated using the Cochrane collaboration tool for risk of bias assessment. The main findings indicate that exercise is a powerful stimulus to increase MCT1 protein content in human muscle. MCT4 protein level increases can also be observed after a training program, although its responsiveness is lower compared to MCT1. Both transporters seem to change independently of exercise intensity, but the responses that occur with each intensity and each duration need to be better defined. The effect of exercise on muscle mRNA results is less defined, and more research is needed especially in humans. Moreover, results in rodents only agree with human results on the effect of a training program on MCT1 protein levels, indicating increases in both. Finally, we addressed important and feasible methodological aspects to improve the design of future studies.
The goal was to analyze the effect of two different training programs on functional autonomy, balance, and body composition in aged women and to determine the influence of their cognitive function.
...Older women aged between 60 to 80 years old were invited to participate in the study. A block randomisation method was used to allocate participants to the Pilates group (PEP), the Muscular group (MEP) and the control group (CG) with equal sample sizes (n = 20). PEP or MEP were required to train twice a week (1 hour/session) in a moderate to vigorous intensity for 18 weeks. Functional autonomy was assessed with the GDLAM protocol. The cognitive function, withthe Mini-Mental State (MMS). Static balance, with a force platform (Kistler 9286AA). Body composition, with a dual-energy X-ray bone densitometry. Research staff performing the assessment and statistical analysis was blinded.
Eighty participants were randomized, 16 women did not meet the inclusion criteria and 4 refused to participate. 60 participants were analysed. Either Pilates or Muscular group improved significantly (P ≤ 0.05) in every GDLAM test. Pilates had a better general functional condition index (IG) than the Muscular group (P = 0.042). There was a significant interaction (P ≤ 0.05) between the cognitive function and two items of the GDLAM test. The amplitude of displacement of the center of pressure in the antero-posterior plane decreased significantly in the Muscular group (P = 0.04). The total lean body increased in the Pilates (P =< .001) and the Muscular groups (P = 0.05).
Pilates should be recommended for improving the general functional condition of older women, while the Muscular exercise is effective for enhancing the static balance. Both exercise programs are effective for increasing the total lean body. The cognitive function interacts with some functional autonomy parameters
Trial registration: ClinicalTrials.gov (identifier: NCT02506491; available from https://clinicaltrials.gov/show/NCT02506491).
•Pilates resulted in a greater increase in the general functional condition of older women than muscular exercise program.•Better cognitive function led to better agility pattern as well as to a better general functional condition.•Pilates and muscular exercise programs led to significant increase in lean body mass.•Muscular exercise program improved the two-leg static balance.
Human and animal studies have shown that Hesperidin has the ability to modulate antioxidant and inflammatory state and to improve aerobic performance. The main objective of this study was to assess ...whether the acute intake of 500 mg of 2S-Hesperidin (Cardiose
) improves antioxidant status, metabolism, and athletic performance, during and after a rectangular test (aerobic and anaerobic effort). For this, a crossover design was used in 15 cyclists (>1 year of training), with one week of washout between placebo and Cardiose
supplementation. After the intervention, significant differences in average power (+2.27%,
= 0.023), maximum speed (+3.23%,
= 0.043) and total energy (∑ 4 sprint test) (+2.64%,
= 0.028) between Cardiose
and placebo were found in the best data of the repeated sprint test. Small changes were also observed in the activity of catalase, superoxide dismutase, reduced glutathione concentration and oxidized/reduced glutathione (GSSG/GSH) ratio, as well as the lipoperoxidation products (thiobarbituric acid reactive substances; TBARS), at different points of the rectangular test, although not significant. Our findings showed improvements in anaerobic performance after Cardiose
intake, but not in placebo, suggesting the potential benefits of using Cardiose
in sports with a high anaerobic component.
Highlights • In middle-aged women, low-moderate levels of programmed exercise for 12-16 weeks had a positive effect on sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI), when ...compared with controls. • In a subgroup analysis, moderate levels of programmed exercise (aerobic exercise) had a positive effect on sleep quality measured by the Pittsburgh Sleep Quality Index, while low levels of physical activity (yoga) did not have a significant effect. • There was a non-significant reduction in the severity of insomnia measured with the Insomnia Severity Index score compared with controls.
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