The Use of Free Weight Squats in Sports: A Narrative Review-Squatting Movements, Adaptation, and Sports Performance: Physiological.

ABSTRACT: Stone, MH, Hornsby, G, Mizuguchi, S, Sato, K, Gahreman, D, Duca, M, Carroll, K, Ramsey, MW, Stone, ME, and Haff, GG. The use of free weight squats in sports: a narrative review-squatting movements, adaptation, and sports performance: physiological. J Strength Cond Res 38(8): 1494-1508, 2024-The squat and its variants can provide numerous benefits including positively affecting sports performance and injury prevention, injury severity reduction, and rehabilitation. The positive benefits of squat are likely the result of training-induced neural alterations and mechanical and morphological adaptations in tendons, skeletal muscles, and bones, resulting in increased tissue stiffness and cross-sectional area (CSA). Although direct evidence is lacking, structural adaptations can also be expected to occur in ligaments. These adaptations are thought to beneficially increase force transmission and mechanical resistance (e.g., resistance to mechanical strain) and reduce the likelihood and severity of injuries. Adaptations such as these, also likely play an important role in rehabilitation, particularly for injuries that require restricted use or immobilization of body parts and thus lead to a consequential reduction in the CSA and alterations in the mechanical properties of tendons, skeletal muscles, and ligaments. Both volume and particularly intensity (e.g., levels of loading used) of training seem to be important for the mechanical and morphological adaptations for at least skeletal muscles, tendons, and bones. Therefore, the training intensity and volume used for the squat and its variations should progressively become greater while adhering to the concept of periodization and recognized training principles.

Effectiveness of supervised Kegel exercises using bio-feedback versus unsupervised Kegel exercises on stress urinary incontinence: a quasi-experimental study.

INTRODUCTION AND HYPOTHESIS: The objective was to investigate and compare the efficacy of supervised Kegel exercises with bio-feedback on stress urinary incontinence (SUI) and pelvic floor muscle strength (PFMS) compared with unsupervised Kegel exercises. METHOD: Matched-group quasi-experimental study of 29 female participants divided into two groups (supervised and non-supervised) was conducted over 12 weeks. Baseline measurements of PFMS were undertaken by a women's health physiotherapist and a Kegel exercise regime bespoke designed for each participant. The supervised group visited the physiotherapist monthly for bio-feedback training (BT); the unsupervised group continued at home with their individualised Kegel exercises. Data were collected via a perineometer (Peritron™) and self-reporting responses to questionnaires. All participants received a final PFMS measurement on completion of the study. RESULTS: Overall Incontinence Severity index (ISI) score was significantly lower in the supervised group post-intervention. Wilcoxon signed-rank tests indicated that supervised Kegel exercises significantly reduced frequency (p= 0.002) and severity (p= 0.020) of overall ISI. Analysis of PFMS were not significantly different, despite an increase in maximum voluntary contraction or pelvic floor muscle strength (PFMS) (p= 0.032) in the supervised group. Of the questionnaires, results of Wilcoxon signed-rank tests indicated that "total bother" was significantly reduced (p= 0.005) in the supervised group. The correlation analysis between PFMS and ISI did not reveal any significant results. CONCLUSIONS: The study confirmed that supervised BT is more effective in reducing SUI than unsupervised Kegel exercises, and that this reduction in ISI score did not correlate with the improvement in PFMS.

Correlation of spirometry indices to chest radiology in the diagnosis of chronic airway disease among regional and rural Indigenous Australians.

BACKGROUND: The majority of Indigenous Australians reside in non-urban locations, with reduced access to chest radiology such as computed tomography (CT). Spirometry and chest X-ray (CXR) may be used in the absence of CT; however, the correlation of spirometry indices to CT-defined chronic airway diseases (i.e. chronic obstructive pulmonary disease (COPD) and bronchiectasis) compared with CXR among Indigenous people is sparsely reported. AIM: To evaluate spirometry indices against CXR and CT findings among adult Indigenous Australians. METHODS: Indigenous patients who had undergone a spirometry test between 2012 and 2020 and had a CXR or chest CT scan assessed for the presence (+ )/absence (- ) of airway diseases were included in this study. RESULTS: Of 643 patients (57% female, 31% remote/very remote), 364 (57%) had CT and CXR available. Patients who were 'CT- and CXR- ' for airway diseases (48%) recorded a mean FVC, FEV1 and FEV1 /FVC of 61%, 59% and 0.76 compared to 57%, 49% and 0.66 in the 'CT+ and CXR- ' group and 53%, 39% and 0.58 in the 'CT+ and CXR+ ' group. CXR showed sensitivity (44%) and specificity (88%), while spirometry showed 62% and 77% compared to CT. Spirometry demonstrated predominately restrictive impairment among 'CT- and CXR- ' and mixed/obstructive impairment among 'CT+ and CXR- ' and 'CT+ and CXR+ ' groups. CONCLUSION: Indigenous Australians tend to demonstrate restrictive impairment in the absence of radiological evidence of airway disease. However, in the presence of airway disease, combinations of mixed and obstructive impairments were common. Obstructive impairment shows greater sensitivity for identifying COPD than that shown by CXR; however, CXR shows greater specificity. Hence, spirometry in conjunction with chest radiology should be utilised to aid in the assessment of airway diseases in this population.

Aerobic training mitigates the negative impact of diabetes on fertility.

Diabetes negatively affects the reproductive system. This present study investigated the effects of aerobic training on protamine 1 and 2 mRNA expression, sex hormones, antioxidant defence and sperm quality in diabetic rats. Thirty-six male Wistar rats were randomly allocated into three groups including diabetic training (DT) group, diabetic (D) group and control (C) group. Rats in DT were exercised 5 times per week for 8 weeks. Blood samples were collected for evaluation of sex hormones 48 h after the last training session. Also, the testes were removed and subjected to histological evaluation and semen analysis. Testicular mRNA expressions of protamines were determined by RT-qPCR. Protamines 1 and 2, and the ratio of protamine 1 to protamine 2 were significantly lower in DT and D groups compared with C group (p < 0.01). LH and testosterone levels were significantly lower in D group compared with DT and C group (p < 0.01). Malondialdehyde was significantly lower in DT and C groups compared with D group (p < 0.001). Sperm parameters were significantly lower in D group compared with C group (p < 0.01). Our findings suggest that aerobic training may mitigate the negative impact of diabetes on sex hormones, oxidative stress, protamine content and sperm parameters in male rats.

Selected root plant supplementation reduces indices of exercise-induced muscle damage: A systematic review and meta-analysis.

This systematic review and meta-analysis examined the effects of selected root plants (curcumin, ginseng, ginger and garlic) on markers of muscle damage and muscular performance measures following muscle-damaging protocols. We included 25 studies (parallel and crossover design) with 353 participants and used the PEDro scale to appraise each study. Forest plots were generated to report on standardised mean differences (SMD) and p-values at 24 and 48 hours following the muscle-damaging protocols. The meta-analysis showed that the supplemental (SUPP) condition showed significantly lower levels of indirect muscle damage markers (creatine kinase, lactate dehydrogenase and myoglobin) and muscle soreness at 24 hours and 48 hours (p < 0.01) than the placebo (PLA) condition. The inflammatory markers were significantly lower for the SUPP condition than the PLA condition at 24 hours (p = 0.02), although no differences were identified at 48 hours (p = 0.40). There were no significant differences in muscular performance measures between the SUPP and PLA conditions at 24 hours and 48 hours (p > 0.05) post-exercise. According to our qualitative data, a number of studies reported a reduction in oxidative stress (e.g., malondialdehyde, superoxide dismutase) with a concomitant upregulation of anti-oxidant status, although other studies showed no effects. Accordingly, selected root plants minimised the level of several biomarkers of muscle damage, inflammation and muscle soreness during periods of exercise-induced muscle damage. However, the benefits of these supplements in ameliorating oxidative stress, increasing anti-oxidant status and accelerating recovery of muscular performance appears equivocal, warranting further research in these outcome measures.

Urinary Incontinence in Competitive Women Weightlifters.

ABSTRACT: Wikander, L, Kirshbaum, MN, Waheed, N, and Gahreman, DE. Urinary incontinence in competitive women weightlifters. J Strength Cond Res 36(11): 3130-3135, 2022-Urinary incontinence has the potential to diminish athletic performance and discourage women from participating in sport and exercise. This study determined the prevalence and possible risk factors for urinary incontinence in competitive women weightlifters. This research was a cross-sectional, survey-based study completed by 191 competitive women weightlifters. The frequency and severity of urinary incontinence was determined using the Incontinence Severity Index. Urinary incontinence was defined as an Incontinence Severity Index score >0. The survey questions focused on risk factors, the context and triggers for urinary incontinence, and self-care strategies. Approximately, 31.9% of subjects experienced urinary incontinence within 3 months of completing the survey. Incontinence Severity Index scores were significantly correlated with parity ( r = 0.283, p = 0.01) and age ( r = 0.216, p = 0.01). There was no significant correlation between the Incontinence Severity Index score and the number of years participating in any form of resistance training ( r = -0.010, p = 0.886) or weightlifting ( r = -0.045, p = 0.534), body mass index ( r = 0.058, p = 0.422), or competition total ( r = -0.114, p = 0.115). The squat was the most likely exercise to provoke urinary incontinence. Although the number of repetitions, weight lifted, body position, and ground impact may increase the likelihood of urinary incontinence occurring during a lift, it is difficult to determine which factor has the greatest influence. Some self-care strategies used by competitive women weightlifters who experience urinary incontinence, such as training while dehydrated, have the potential to diminish athletic performance.

The effect of leaf extract supplementation on exercise-induced muscle damage and muscular performance: A systematic review and meta-analysis.

This systematic review and meta-analysis investigated the effects of leaf-plant extracts typically used for tea beverages on the level of exercise-induced muscle damage. The meta-analysis was conducted by comparing measures between the leaf-extract supplements (SUPP) and placebo (PLA) conditions at 24 h and 48 h following the muscle-damaging protocols from 19 studies with 416 participants. The results showed that the SUPP condition exhibited significantly lower indirect muscle damage markers than the PLA condition at 24- and 48-h post-exercise (p < 0.05). Furthermore, oxidative stress markers were significantly lower for the SUPP condition than the PLA condition at 24-h post-exercise (p < 0.05), although not at 48-h post-exercise (p > 0.05). In addition, no differences were found for anti-oxidant status at 24- and 48-h post-exercise (p > 0.05) between conditions. Muscle performance measures significantly increased for the SUPP condition than the PLA condition at 24-h post-exercise (p < 0.05), but not at 48-h post-exercise (p > 0.05). These results demonstrate that leaf plant extracts reduces the level of various biomarkers indicative of exercise-induced stress, although its effect on anti-oxidant status remains equivocal. Nonetheless, leaf-plant extracts typically ingested as a tea beverage may be an effective recovery strategy following strenuous exercises.

Regular training has a greater effect on aerobic capacity, fasting blood glucose and blood lipids in obese adolescent males compared to irregular training.

BACKGROUND/OBJECTIVE: It is not clear whether the regularity of training affects the outcomes of aerobic exercise. This study aimed to compare the effects of regular with irregular training on aerobic fitness, blood markers, and anthropometric characteristics of obese adolescent males. METHODS: Twenty three male students between 16 and 17 years old were randomly assigned into regular exercise (RE) group and performed exercises on specific time and days each week, or irregular exercise (IE) group and performed exercise on randomly selected days each week. The intervention programs consisted of self-paced progressive running program (20 min in week one and 44 min in week 8), three times per week for eight weeks. Anthropometric characteristics, blood lipids, fasting blood glucose, and aerobic capacity were assessed before and after the intervention using a two-way ANOVA. RESULTS: There was a significant interaction of time and condition on total cholesterol (TC) F (1, 21) = 5.427, p = 0.030, η P 2  = 0.205, and high-density lipoprotein to low-density lipoprotein ratio (HDL)/(LDL) F (1, 21) = 5.951, p = 0.024, η P 2  = 0.221), with a greater reduction observed in RE group. LDL decreased only in RE group demonstrating a significant effect of time F (1, 21) = 4.897, p = 0.038, η P 2  = 0.189. Body mass, body mass index (BMI), and waist circumference decreased, and VO2peak increased in both groups with no significant difference between groups. There was no significant effect of time or condition on waist to hip ratio (WHR), fasting blood glucose (FBG), triglycerides (TG), HDL, TC/HDL, or TG/HDL (p > 0.05). CONCLUSION: Although both RE and IE improved VO2peak and some anthropometric measures, changes in TC, LDL, and HDL/LDL were more predominant in response to RE. Therefore, to achieve greater adaptations to aerobic exercise, overweight and obese adolescents should perform exercise regularly.

Caffeinated Chewing Gum Improves Bicycle Motocross Time-Trial Performance.

This study aimed to identify the acute effects of caffeinated chewing gum (CAF) on bicycle motocross (BMX) time-trial (TT) performance. In a randomized, placebo-controlled, double-blind cross-over design, 14 male BMX riders (age = 20.0 ± 3.3 years; height = 1.78 ± 0.04 m; body mass = 72 ± 4 kg), consumed either (300 mg; 4.2 ± 0.2 mg/kg) caffeinated (300 mg caffeine, 6 g sugars) or a placebo (0 mg caffeine, 0 g sugars) gum, and undertook three BMX TTs. Repeated-measure analysis revealed that CAF has a large ergogenic effect on TT time, F(1, 14) = 33.570, p = .001, ηp2=.71; -1.5% ± 0.4 compared with the placebo. Peak power and maximal power to weight ratio also increased significantly compared with the placebo condition, F(1, 14) = 54.666, p = .001, ηp2=.79; +3.5% ± 0.6, and F(1, 14) = 57.399, p = .001, ηp2=.80; +3% ± 0.3, respectively. Rating of perceived exertion was significantly lower F(1, 14) = 25.020, p = .001, ηp2=.64 in CAF (6.6 ± 1.3) compared with the placebo (7.2 ± 1.7). Administering a moderate dose (300 mg) of CAF could improve TT time by enhancing power and reducing the perception of exertion. BMX coaches and riders may consider consuming CAF before a BMX race to improve performance and reduce rating of perceived exertion.

Postactivation potentiation effect of two lower body resistance exercises on repeated jump performance measures.

This study examined the postactivation potentiation effects of combining squat and deadlift exercises on subsequent repeated jump performance. Fifteen, resistance-trained youth wrestlers were randomly allocated to either undertake back squats (BSq), deadlift (DL) or BSq and DL as supersets (BSq+DL), with a repeated jump protocol performed 8-minutes post-exercise in each session. Thereafter, a control condition (CON) was completed involving a general warm-up, followed by the repeated jump protocols. Power outputs, flight time, contact time and reactive strength index were recorded from each repeated jump protocol. Measures were compared between the BSq, DL and BSq+DL sessions and between sessions that generated the best power output (BEST) with CON via inferential statistics and effect size (ES) calculations. The BSq condition exhibited significantly greater power output compared to the CON condition (p<0.05, ES = 1.07), although no differences were identified for the other conditioning activities. Furthermore, power output, flight time and reactive strength index were significantly greater for the BEST compared to the CON condition (p<0.05, ES = 0.97-1.47). Results indicated that BSq was the optimal conditioning activity to increase power output during a repeated jump protocol. However, greater improvement during the BEST condition suggests that the type of conditioning activity should also be considered on an individual-basis.

Prevalence of urinary incontinence in women powerlifters: a pilot study.

INTRODUCTION AND HYPOTHESIS: Increased intra-abdominal pressure is associated with urinary incontinence (UI) as is increasing age, obesity, and participating in sport at an elite level. We aimed to determine the prevalence of UI in competitive women powerlifters and establish if commonly cited risk factors affect the incidence of UI. METHODS: The authors developed a 17-item questionnaire to investigate the prevalence of UI and the relationship of UI with age, body mass, resistance training experience, and competition grade in competitive women powerlifters. The questionnaire was distributed through three major powerlifting federations in Australia for 16 months. The data of 134 competitive women powerlifters were collected anonymously using Qualtrics, and were analysed using multivariate analysis. RESULTS: In combination, the age of lifters, resistance training experience, body weight categories, and competition grade accounted for a significant 28% of the variability in the Incontinence Severity Index (ISI) (p < 0.01). However, the ISI was not significantly different among age groups, body weight categories, or competition grade. Approximately, 41% of women powerlifters had experienced UI at some stage in life, and 37% of women powerlifters currently experienced UI during training, competition, or maximum effort lifts. However, the rate of UI experienced during daily life activities was approximately 11%. CONCLUSIONS: This study showed that competitive women powerlifters experience a higher rate of UI during lifting-related activities than in daily life and that the rate of UI correlates positively with age, body weight categories, resistance training experience, and competition grade.

Effects of physical training on coagulation parameters, interleukin-6, and angiotensin-converting enzyme-2 in COVID-19 survivors.

COVID-19 is a highly contagious virus that uses Angiotensin-converting enzyme 2 (ACE2) as a receptor to enter human cells. The virus leads to an increase in inflammatory cytokines (i.e. IL-6) and an impaired coagulation system, which can cause serious complications during and after the disease. Physical exercise has been shown to improve COVID-19 complications through various mechanisms, such as modulation of the immune and coagulation systems. Therefore, this study investigated the effects of 8 weeks of training on inflammatory, coagulation, and physical factors in patients with COVID-19 during the recovery phase. Twenty-seven male and female volunteers (age 20-45 years) who recently recovered from COVID-19 were assigned to the control (n = 13) or the training group (n = 14). Blood samples, aerobic capacity and muscle endurance were collected 24 h before the start of the interventions and 24 h after the final training session in week 4 and 48 h after the final training session in week 8. IL-6, ACE2, fibrinogen, and D-dimer were measured using ELISA. The training group showed a significant increase in muscle endurance (p = 0.004) and aerobic capacity (p = 0.009) compared to the control group. Serum levels of IL-6 and fibrinogen decreased in the training group but this decrease was not statistically significant (p > 0.05). Despite a slight increase in the quality of life and sleep in the training group, no statistically significant difference was observed between the training and the control group. It appears that physical training has beneficial effects on the coagulation system, inflammatory factors, and sleep quality and can facilitate the recovery of COVID-19 patients.

Does a Kegel Exercise Program Prior to Resistance Training Reduce the Risk of Stress Urinary Incontinence?

This comparative pre-post intervention study investigated the feasibility and benefits of Kegel exercises amongst incontinent women, prior to commencing resistance training (RT), to reduce the risk of stress urinary incontinence (SUI) compared to a group of women without prior Kegel exercises (KE). Incontinence severity index (ISI) score, pelvic floor muscle strength (PFMS), and body composition (such as body mass index (BMI), fat, and muscle mass), were obtained pre and post intervention. Results demonstrated that RT reduced SUI to a significantly greater extent only if preceded by KE as was observed in the Kegel exercise plus RT group (KE + RT) over time. The improvements in total ISI in both the KE + RT and RT groups were large (d = 1.50 and d = 1.17 respectively). A two-way ANOVA indicated a statistically significant improvement in average PFMS within the KE + RT group over time and between the two groups. A positive correlation was found between the average strength of pelvic floor muscles and SUI. Participants in KE + RT group demonstrated a significant increase in muscle mass (p ≤ 0.001) and concomitant reduction in fat mass (p = 0.018). This study determined a dedicated program of KE preceding a RT program improved average pelvic floor muscle strength and was effective in reducing SUI among incontinent women.

Effects of Knowledge of Results and Change-Oriented Feedback on Swimming Performance.

PURPOSE: This study examined the effect of providing knowledge of results (KR) with, and without, promotion- and change-oriented feedback on repeated-sprint ability in swimmers. METHODS: Twenty-nine male and female swimmers (age = 16 [1] y, height = 1.74 [0.07] m, body mass = 61.0 [8.4] kg) were randomly allocated into 2 different feedback conditions, or a condition without feedback (NoFb), as a crossover, repeated-measures design. In one feedback condition, the swimmers were provided with lap completion times as KR. The other feedback condition was athlete-driven, where the swimmers were asked to estimate their lap completion times, and the investigators responded on whether their actual sprint times were faster (promotion-oriented), slower (change-oriented), or the same. RESULTS: The results showed significantly faster average completion times during the repeated-sprint swim protocol in the athlete-driven KR (P = .014) and KR condition (P = .023), when compared with the NoFb condition. However, significantly faster best completion time was only found in the KR condition (P = .012), when compared with the NoFb condition. Furthermore, the stroke rate was significantly greater during the athlete-driven KR (P = .009) and KR (P = .021) conditions, when compared with the NoFb condition. CONCLUSIONS: The KR condition exhibited the greatest benefit for improving several swimming performance measures during a repeated-sprint protocol, and the increase in stroke rate may have contributed to this performance enhancement. Thus, it is recommended that swimmers receive lap completion times during repeated-sprint training sessions to optimize training quality.

Association Between Obstetric History and Urinary Incontinence in a Cohort of Resistance-Trained Women.

Purpose: Urinary incontinence has the potential to reduce participation in sport and exercise and diminish athletic performance. The purpose of this study was to explore the association between obstetric history and urinary incontinence in a cohort of resistance-trained women. Patients and Methods: This international, cross-sectional survey was completed by 1252 women competing in either powerlifting, weightlifting or CrossFit. The Incontinence Severity Index determined the severity of urinary incontinence. Results: Almost 43% of the participants experienced urinary incontinence in the threemonths prior to the study. The prevalence of urinary incontinence in this cohort according to mode of birth were: caesarean 42.6%, unassisted vaginal 59.3%, vacuum extraction 58.8%, forceps 60.3%, vaginal and caesarean births 66.2%, forceps and vacuum extraction 73.1%. The prevalence of urinary incontinence in the subgroup of women who had undergone urogenital surgery was 63.6%. Kendall's tau-b indicated that the correlation between ISI score and the number of births was strong and positive (τ = 0.25, p < 0.001). Conclusion: Our results suggest that both the number of births and mode of birth influenced the likelihood of urinary incontinence in resistance-trained women. Women who had experienced only caesarean births had the lowest likelihood of urinary incontinence, while women who had experienced both vaginal and caesarean births had the most severe and second highest likelihood of urinary incontinence. Women who had undergone urogenital surgery continued to experience a high likelihood of urinary incontinence.

Deceptive intensities: An exploratory strategy for overcoming early central fatigue in resistance training.

Neuropsychological stress induced by misleading information can limit human performance, possibly by early central fatigue mechanisms. In this study, we investigated the impact caused by prescribing misleading intensities of resistance exercise on acute electroencephalogram (EEG) and electromyogram (EMG) responses and the total number of repetitions to exhaustion. Collegiate female students performed three sets of biceps curls to exhaustion. The actual intensity for all sets was set at 65% 1-Repetition Maximum (1-RM). However, participants were deceptively informed that the intensities were 60%, 65%, or 70% 1-RM. The number of repetitions to fatigue and the magnitude of EEG and EMG signals were analyzed. The number of repetitions to exhaustion was significantly lower in greater announced intensities (18.11 ± 8.44) compared to lower (29.76 ± 16.28; p = 0.017) and correctly (27.82 ± 11.01; p = 0.001) announced intensity. The correlation between frontal and motor-cortex signals was significant in lower (r = 0.72, p = 0.001) and higher (r = 0.64, p = 0.005) announced intensities. The median and mean frequencies of EMG signal and Root Mean Square (RMS) did not show any significant difference between sets, but the peak-to-peak range (PPR) of biceps EMG signals was significantly higher in lower intensity (0.145 ± 0.042) when compared with higher (0.104 ± 0.044; p = 0.028) or correctly (0.126 ± 0.048; p = 0.037) announced intensity. It seems that deceptive information regarding the mass of an object could affect the number of repetitions to exhaustion and PPR to cover muscle capacity in endurance-type strength training.

Bibliometric Profile and Density Visualizing Analysis of Yoga Intervention in Type 2 Diabetes: A 44 - Year Study on Global Scientific Research Output from 1975 to 2019.

The aim of the paper is to provide an in-depth evaluation of the research output of yoga intervention on type 2 diabetes mellitus from 1975 to 2019 using large-scale data analysis, bibliometric indicators, and density equalizing mapping. Data related to yoga-diabetic research, as search descriptors were retrieved using the Scopus database. The most common bibliometric indicators were annual research output, total citations, productive countries and leading authors, journals and institutions, and frequently cited articles. The number of global research articles retrieved for yoga-diabetic research over the study period 1975-2019 was 411. The growth rate of global publications in 2015-2019 is four times as high as in 1975-2003. The total number of citations for the retrieved articles was 7189, and the average number of citations per article was 23.82. Of these journals, the Journal of Alternative and Complementary Medicine has published the highest number of papers, which accounts for 2.9% of total publications. This study showed a wide variety of journals in which yoga-diabetic articles are published; these bibliometric indicators provide useful information on performance assessment of productivity and quality of research output. Therefore, this study provides a helpful reference for endocrinologists, yoga therapists, policy decision-makers, and diabetes researchers.

Fruit supplementation reduces indices of exercise-induced muscle damage: a systematic review and meta-analysis.

This systematic review and meta-analysis examined the effects of fruit supplements on indices of muscle damage and physical performance measures following muscle-damaging exercise protocols. The PEDro scale and Cochrane's risk of bias tool was used to critically appraise each study, whilst forest plots were generated to report on standardised mean differences (SMD) and p-values. The studies employed a crossover-randomised design, or a randomised controlled placebo design, with measures compared between the supplement (SUPP) and placebo (PLA) conditions at 24 and 48 h following the muscle-damaging exercise protocols. Compared to the PLA condition, the SUPP condition exhibited significantly lower levels of indirect muscle damage markers (p = 0.02; I2 = 44%), inflammatory markers (p = 0.03; I2 = 45%) and oxidative stress (p < 0.001; I2 = 58%), whilst antioxidant capacity was significantly increased (p = 0.04; I2 = 82%) at 24 h post-exercise. The maximal isometric voluntary contraction was significantly greater for the SUPP condition than the PLA at 24 h (p < 0.001; I2 = 81%) and 48 h (p < 0.001; 84%) post-exercise. Only a few studies reported on functional outcome measures (i.e. countermovement jump, cycling, sprint and running maximal oxygen uptake), and the findings appeared conflicting according to qualitative analyses. Fruit supplementation minimised the level of several biomarkers of muscle damage, inflammation and oxidative stress, whilst improved muscular contractility during periods of EIMD. These findings demonstrate that fruit supplements could be used as recovery strategies from strenuous exercise sessions.

Development of Sham Yoga Poses to Assess the Benefits of Yoga in Future Randomized Controlled Trial Studies.

BACKGROUND: Although research has demonstrated the benefits of yoga to people who have been diagnosed with diabetes or at risk of diabetes, studies have not confirmed these effects can be ascribed to the specific features of the traditional postures, called asanas. Instead, the effects of asanas could be ascribed to the increase in cardiovascular activity and expenditure of energy or to the expectation of health benefits. Therefore, to establish whether asanas are beneficial, researchers need to design a control condition in which participants complete activities, called sham poses, that are equivalent to traditional asanas in physical activity and expectation of benefits. OBJECTIVES: The aim of this research was to design an appropriate suite of sham poses and to demonstrate these poses and traditional asanas are equivalent in energy expenditure, cardiovascular response, and expectations of health benefits. METHODS: Twenty healthy men at medium to high risk of developing diabetes volunteered to partake in the current study. These men completed two sessions that comprised traditional asanas and two sessions that comprised sham poses-poses that utilize the same muscle groups as the asanas and were assigned fictitious Sanskrit labels. Before and after each session, heart rate, blood pressure, blood glucose levels, triglycerides levels, and oxygen saturation were measured to gauge the intensity of exercise. After each session, using a standard measure, participants also indicated the degree to which they expected the poses to improve health. RESULTS: The degree to which the sessions affected the physiological measures (for example, pre-exercise, the heart rate for yoga and sham was 71.06 ± 4.79 and 73.88 ± 6.05, respectively, and post-exercise, the heart rate was 70.19 ± 6.16 and 73 ± 7.55, respectively) and the expectations of health improvements did not differ between the traditional asanas and the sham poses. Likewise, the degree to which each session influenced these physiological measures was negligible in both conditions. CONCLUSIONS: This study developed a series of poses that elicit similar physiological and psychological effect as traditional yoga asanas. These poses can be used in an active control group in future randomized trial studies that are designed to assess the benefits of asanas.

Determinant physiological factors of simulated BMX race.

Evaluating the physiological demands of BMX cycling on a track provides coaches with the information required to prescribe more effective training programmes. To determine the relative importance of physiological factors during simulated BMX race, 12 male riders (age 19.2 ± 3.5 years, height 1.76 ± 0.06 m, mass 68.5 ± 4.3 kg) completed a maximum aerobic capacity (V̇O2max) test in a laboratory, and a week later, completed six laps on a BMX track interspersed by 15 min passive recovery. Peak power, immediate post-lap V̇O2peak, blood lactate, and heart rate were measured in each lap. Peak power to weight ratio was significantly correlated with lap time, however, the strength of this association decreased in each subsequent lap. Mean V̇O2peak was greater than 80% of laboratory-measured V̇O2max in every lap, indicating a strong contribution of the aerobic energy system during BMX racing. This study also identified that mean blood lactate was significantly associated with lap time, which showed the importance of the anaerobic energy system contribution to BMX race. Despite the short period of pedalling during BMX racing, both aerobic and anaerobic energy systems are important contributors to lap performance. Coaches should consider maximising both anaerobic power and aerobic capacity to improve riders' overall performance in multiple laps.