The present study aimed to test if a long-term passive stretching training causes adaptations of the medial gastrocnemius architecture and the Achilles tendon (AT) tangent modulus.
A total of 20 males took part in the study. The stretching group (n = 12), performed stretching exercises for the plantar flexors for 10 weeks, 4–5 times a week, which comprised two static positions sustained twice each during 30 s.
For the stretching group, maximum dorsiflexion angle, peak passive torque, and muscle–tendon unit maximum length significantly increased after training. No other differences were found related to muscle architecture and AT tangent modulus.
Joint amplitude gain after a long-term stretching of the triceps surae was not accompanied by structural or mechanical changes of the medial gastrocnemius and AT tendon, and seems to reflect an increasing stretch tolerance level.
Isometric strength training (IST) with rapid non-sustained contraction (RIST) is effective in improving the ability to generate force rapidly. However, the neuromuscular adaptation of IST with sustained contraction (SIST) and RIST is not known. Therefore, the aim of the study was to compare the neuromuscular adaptations of RIST with SIST.
Thirty-three national floorball players (23.9 ± 3.1 years old; 1.69 ± 0.08 m; 64.6 ± 11.1 kg) were recruited for this study. Pre- and post-test included countermovement jump (CMJ), 30-m sprint (TT30), isometric squat at 90° (ISqT90) and 120° (ISqT120) knee angles. They were randomly assigned to either control (Con) (n = 9), RIST (n = 12) or SIST (n = 12) group and performed 12 sessions of intervention training. All groups performed the same sets of exercises, but RIST and SIST had to perform ISqT with and without sustained contraction, respectively.
Time × group effect for CMJ height (P = 0.01, ƞ p 2 = 0.25), peak force (PF) (P = 0.03, ƞ p 2 = 0.22) and rate of force development (RFD) (P = 0.02, ƞ p 2 = 0.22) obtained from ISqT120 were noted. A main effect for time was observed in CMJ height, PF obtained from ISqT90 and ISqT120, and RFD obtained from ISqT90 (P < 0.01, 0.27 < ƞ p 2 < 0.57). There was greater improvement in TT30 (P = 0.043, d = 3.00), ISqT90 PF (P = 0.034, d = 3.12), ISqT120 PF (P = 0.003, d = 4.54) and ISqT120 RFD (P = 0.033, d = 1.36) in the SIST than the Con group.
SIST was more effective in improving strength and dynamic performance as compared to RIST, making it a viable training method to enhance dynamic performances.
Different periodization models have been widely used to improve maximum and rapid force in aging adults. However, it is unclear if some specific model can influence the remarkable heterogeneity of responsiveness to rapid torque improvements following resistance training.
Compare the effects of mixed session periodization (MSP) and traditional (TP) models on neuromuscular performance and individual responsiveness in aging adults.
Twenty-two aging men and women (64.6 ± 5.2 years old; 1.68 ± 0.1 m; 77.8 ± 16.0 kg) completed the intervention period. They were assigned into MSP (n = 11) or TP (n = 11) resistance training for lower limbs. The outcome measures normalized dynamic leg press (5-RM:BM), absolute and normalized knee isometric peak torque (PT and PT:BM) and rate of torque development, and impulse were assessed at baseline and after three blocks of a 9-wk resistance training (3 sessions per week). Thigh leg lean mass was assessed by dual-energy x-ray absorptiometry at baseline and after the intervention.
Similar increases were observed for 5-RM:BM (MSP: 28.8% ± 13.5% and TP: 26.4% ± 7.6%, P < 0.001), PT (MSP: 223.7 ± 50.7 N·m and TP: 189.9 ± 58.6 N·m, P < 0.001), but it was not observed for PT:BM (MSP: 16.4% ± 16.5% and TP: 4.7% ± 9.2%, P > 0.05). Absolute and normalized RTD remained unchanged throughout intervention (P > 0.05), but both groups improved impulse (MSP: 22.1% ± 25.7% and TP: 12.6% ± 45.2%, P < 0.001). Only MSP responders (n = 5) presented significant time effect for absolute RTD (P < 0.05) and impulse (P < 0.05).
Although both periodization protocols increased 5-RM:BM and PT, it was not interchangeable through improvements in RTD even adopting power training session. Furthermore, these results suggest a great inter-individual variability following different periodization models for aging people.
External Counterpulsation (ECP) is a well-established treatment for coronary disease, with interest growing in the potential to act as a sports recovery modality or pre-performance strategy. This pilot study compared the effects of different ECP durations upon neuromuscular function (NF), cortisol and subjective perceptions in a rested state.
Eleven physically active male volunteers received two ECP treatments (Renew Sport, Singapore) of differing duration (20-min and 40-min) in a randomised, repeated measures crossover design. Testing occurred pre-ECP, post-ECP, and 24-h post-ECP. NF testing comprised counter-movement jumps (CMJs) and 6-s sprint cycling. Saliva samples were analysed for cortisol. Rate of Perceived Exertion (RPE, 6 to 20) and Bipolar Comfort Scales (− 10 to 10) quantified participants’ experiences, and ECP duration preference was examined. Repeated measures ANOVA and effect size (ES: Cohen’s d) analysed NF and cortisol results. Paired t-tests analysed RPE and comfort ratings.
ECP demonstrated no effect, neither positive nor negative, upon NF outcome measures in both groups. A trend of reduced salivary cortisol levels across both groups following ECP was observed (P = 0.066). No RPE difference existed between groups. 20-min of ECP was rated as significantly more comfortable than 40-min (P < 0.05) and participants predominantly identified the 20-min ECP session as “more acceptable”.
These results indicate that there were no effects for either duration upon the defined outcome measures, and thus, in these circumstances, no differences between the two durations were observed with respect to effects upon NF and salivary cortisol. The use of ECP warrants further investigation for potential benefits to performance before it can be proposed as an effective preparatory modality.
There has been considerable innovation and advancement in the field of exercise and physical activity (PA). In regards to the battle against chronic non-communicable disease, however, we believe the model of PA that would prove most salutary is one closely mimicking that of our hunter-gatherer ancestors. For the purpose of longevity, the human body and our genetic makeup have been evolutionarily adapted to respond best to moderate amounts of high-intensity interval training, in conjunction with high amounts of low intensity exercise. Moreover, to optimize resiliency and cardiorespiratory fitness, a hunter-gatherer fitness regimen must include cross training targeted at flexibility, balance and strength. Though not commonly understood, the health benefits from exercise comprise a reverse J-curve. The endurance athletes residing on the furthest reaches of the PA spectrum appear to lose a substantial portion of the exercise-related longevity and cardiovascular benefits due to cardiac overuse injury. Conversely, there is an emerging body of evidence suggesting leisure time exercise done with peers in a natural environment is significantly superior to that training done in solitude. This idea of the “power of play” lends support to the ancestral model of PA whereby humans are evolutionary adapted to be highly social, outdoor creatures capable of a diverse range of PA at varying intensities.
Quality of life and psychological health in the field of competitive sport are emergent research topics, specifically for issues such as sport anxiety and depression. With the rise of contemplative practices, yoga has started to be used and included as part of athletes’ mental training. This study aimed to systematically review the literature on the impact of yoga interventions on quality of life, performance anxiety and sport performance among healthy elite adult athletes. Based on PRISMA guidelines, this systematic review includes articles published up to December 2019. The search strategy was conducted in six databases (PUBMED, EMBASE, PsycINFO, SCOPUS, SportDiscuss and Érudit). Screened by two independent researchers, only six of the 37 articles drawn from the search met the preselected inclusion criteria and moved forward to the data extraction process. Data from six trials of poor quality (M = 46.91%, SD = 13.39, IRR of 92%) were included in this comprehensive literature search, indicating that elite athletes benefit from yoga interventions (with or without mindfulness), in terms of changes in performance anxiety M = 65% (SD = 122.49), sport performance M = 7.9% (SD = 5.46) and life satisfaction. These interventions lasted on average 5.7 weeks (SD = 2.07). Based on the collected evidence, methodological and measurement limitations of the sport psychology literature should be addressed to improve the replicability of reported results. Overall, this review provides encouraging but limited evidence for the value of yoga interventions in healthy adult athletes. However, the important reporting inconsistencies and theoretical limitations that have been raised highlight the need for trials with greater methodological rigor.
It is known that COVID-19 spread mainly from person-to-person through respiratory droplets produced when an infected person coughs or sneezes, and as a result certain ideas about contagious of COVID-19 have been spread. One of them is the widespread belief that close runners, owing to the stronger exhalation, can be more prone to be infected with COVID-19 because the collision with the suspended respiratory droplets should the runner in front be infected. However, because of the low Stokes number this idea cannot be generalized without carefully thought and in fact can be put into question. Utilizing the raindrop collisional model and with the help of computational fluid dynamics (CFD), it is shown that the probability of collision with respiratory droplets is not always increasing with the approaching velocity of the runner but rather there is a maximum velocity threshold at which the efficiency of collision drops.
In New Zealand, prostate cancer (PCa) is the most commonly diagnosed cancer in men and the third most common cause of male cancer deaths. Among these patients, the most common non-cancer related cause of death is cardiovascular disease (CVD). Aortic arterial stiffness may be clinically viable solution for detecting and tracking CVD risk factor in PCa survivors. The aim of the study was to determine whether aortic arterial stiffness is increased in PCa survivors compared to age-matched controls.
Participants recruited for this prospective comparative study were PCa survivors who had completed treatment (other than endocrine therapy) or were on active surveillance compared, or were age-matched non-cancer controls. During a single 1-h appointment, all participants had measures of aortic arterial stiffness, arterial wave reflection, central blood pressure and body composition taken.
Ninety-eight men were recruited, 51 PCa survivors and 47 controls. There was no significant between group difference for aortic arterial stiffness [12.0 m/s (SD: 1.7) vs. 12.0 m/s (SD: 1.9), P = 0.953, d = 0.0]. Fat free mass [60.7 kg (SD: 4.9) vs. 65.1 kg (SD: 8.3), P = 0.007, d = 0.6] and skeletal muscle index [8.6 kg/m2 (SD: 0.6) vs. 9.0 kg/m2 (SD: 0.9), P = 0.050, d = 0.5] were lower in the PCa group.
Aortic arterial stiffness is not increased (worse) in men with PCa who receive various treatments, compared to age-matched controls. These findings may indicate that factors other than increased aortic arterial stiffness contribute to heightened risk of cardiovascular events in this population.
To determine the relationship between metabolic fitness test scores and performance in police occupational tasks.
Retrospective data from 106 law enforcement officers who completed two metabolic fitness assessments [anaerobic: a 20-m (10-m and 20-m splits) sprint, aerobic: 20 m Multi-Stage Fitness Test (20 m-MSFT)] and three routine occupational tasks [1.22 m Fence jump (FJ), 8.5 m Victim Drag (VD with 102.3 kg) and “Get-up” (GU)] were collected. A Person’s correlation coefficient and a standard multiple regression were used to assess the relationship between and predictive ability of, respectively, the fitness tests scores and performance on occupational tasks.
There was a significant positive correlation between the 10-m sprint scores and FJ (r = 0.524, P < 0.001), VD (r = 0.528, P < 0.001) and GU (r = 0.486, P < 0.001). Similarly, the 20-m sprint scores were significantly and moderately correlated with FJ (r = 0.573, P < 0.001), VD (r = 0.603, P < 0.001) and GU (r = 0.533, P < 0.001). These anaerobic tests’ scores predicted approximately 40% of the performance in the occupational tasks analysed. The MSFT fitness assessment had a small, albeit significant negative correlation with the three tasks: FJ (r = − 0.360, P < 0.001), VD (r = − 0.266, P = 0.012) and GU (r = − 0.375, P < 0.001).
High levels of metabolic fitness correlated with faster performance in police officer occupational tasks, particularly ones of an anaerobic nature (i.e. the maximal sprint tests). In addition to typical aerobic fitness conditioning, anaerobic fitness conditioning could be vital for optimal performance in physically demanding tasks required of police officer.
To compare physical activity and sedentary behavior between four commonly used subjective and objective measures: the 7-day Physical Activity Recall (7DPAR), International Physical Activity Questionnaire (IPAQ), pedometer, and accelerometer.
A total of 130 college students completed four measures for the same 7 days. Body composition was measured using a bioelectric impedance analyzer. Wilcoxon signed rank tests and Spearman correlations were performed to compare estimates between activity measures. The Spearman correlations between different activity measures were further examined separately for the higher and the lower body fat groups.
Compared with accelerometer-derived data, both the 7DPAR and the IPAQ overestimated light physical activity (P < 0.001) while underestimated sedentary behavior (P < 0.001). Across comparisons, the highest correlation was found between accelerometers and pedometers on steps/day (r = 0.72, P < 0.001). The 7DPAR and the IPAQ were correlated with each other for all physical activity variables and sedentary behavior (r = 0.37–0.45). There were low correlations (r = 0.20–0.47) between the 7DPAR, the IPAQ, and accelerometers in sedentary behavior, light physical activity, and vigorous physical activity. Higher correlations between different activity modalities were observed among individuals with lower body fat (r = 0.41–0.80) than among those with higher body fat (r = 0.31–0.65).
The 7DPAR and the IPAQ yielded comparable estimation of moderate physical activity relative to accelerometers. There were significant differences in sedentary time across activity measures. Body compositions should be considered when comparing the estimates of activity levels between subjective and objective instruments.
The purpose of the present study was to examine the day-to-day consistency and inter-subject variability of composite and individual, neuromuscular and torque patterns of responses as a result of a fatiguing bout of maximal, bilateral, isokinetic leg extension muscle actions.
Ten men (Mean ± SD = 21.6 ± 2.5 years) completed two testing visits consisting of pretest and posttest maximal voluntary isometric contractions (MVIC) as well as 25 maximal, bilateral, isokinetic (180°/s), leg extension muscle actions. Electromyographic (EMG) and mechanomyographic (MMG) signals were collected from the vastus lateralis and normalized to the MVIC. Performance fatigability was defined as the percent decline in torque between the average of repetitions 1, 2, and 3 and repetitions 23, 24, and 25. Polynomial regression was used to examine the individual and composite relationships between EMG amplitude (AMP), EMG mean power frequency (MPF), MMG AMP, MMG MPF, and torque versus repetitions.
There was no significant difference (d = 0.80; P = 0.17) in the performance fatigability between Day 1 (19.3% ± 7.1%) and Day 2 (26.9% ± 11.3%). Polynomial regression indicated substantial inter-subject variability, but high day-to-day consistency.
The composite EMG AMP, MMG AMP, and MMG MPF patterns of responses demonstrated consistency across days. The composite EMG MPF patterns of responses, however, were not consistent between Day 1 and Day 2. In addition, based on the high inter-subject variability, future studies should present both composite patterns of neuromuscular responses and the patterns of responses on a subject-by-subject basis to make inferences regarding fatigue-induced changes in motor unit activation strategies.