Plyometric Training in Normobaric Hypoxia improves Jump Performance.

Strength training in hypoxia has been shown to enhance hypertrophy and function of skeletal muscle, however, the effects of plyometric training in hypoxia is relatively unknown. Therefore, this study aimed to examine the effects of plyometric training in hypoxia compared to normoxia on body composition, sprint and jump parameters. Twenty-three male physical education students (20.4±2.0 years, mean±SD) participated in the study and were divided into a plyometric training in hypoxia (PTH, n=8), plyometric training in normoxia (PTN, n=7) or control group (C, n=8). The PTH group trained in normobaric hypoxia (approximately 3536 m) 3 days/week for 8 weeks, while the PTN trained in normoxia. PTH induced significant improvements from baseline to post-testing in countermovement-jump (37.8±6.7 cm, 43.4±5.0 cm, p<0.05), squat-jump (35.4±6.2 cm, 41.1±5.7 cm, p<0.05), drop-jump height (32.8±6 cm, 38.1±6 cm, p<0.05) and 20-m sprint performance (3257.1±109.5 ms, 3145.8±83.6 ms, p<0.05); whereas PTN produced significant improvement only in countermovement-jump (37.3±4.8 cm, 40.5±4.5 cm, p<0.05) and 20-m sprint performance (3209.: 3±76.1 ms, 3126.6±100.4 ms, p<0.05). Plyometric training under hypoxic conditions induces greater improvement in some jump measures (drop-jump and squat-jump) compared to similar training in normoxia.

Running Demands of Provincial Women's Rugby Union Matches in New Zealand.

ABSTRACT: Busbridge, AR, Hamlin, MJ, Jowsey, JA, Vanner, MH, and Olsen, PD. Running demands of provincial women's rugby union matches in New Zealand. J Strength Cond Res 36(4): 1059-1063, 2022-There has been rapid growth in participation in women's rugby but there is minimal research on the sport. The aim of this study was to increase our knowledge of the running demands of high-level female players in the New Zealand Provincial Rugby Competition. Players (n = 20) wore 10-Hz Global Positioning System units during 7 matches to measure total distance covered, all running distance (≥6.4 km·h-1), high-intensity (HI) running (≥16.1 km·h-1), meters per minute (m·min-1), and maximum speed (km·h-1). Mean ± SD were calculated for forwards and backs. Forwards and backs covered a similar total distance (5,616 ± 809 m and 5,852 ± 1,022 m, respectively) and running distance (3,181 ± 583 m and 3,095 ± 805 m, respectively). However, when separated into specific playing positions, the half back recorded significantly higher running distances (4,292 ± 171 m), greater HI running distances (1,003 ± 58 m), and more distance overall (6,812 ± 277 m) than other positions (p ≤ 0.05). By contrast, outside backs did less running (2,456 ± 114 m) than other positions (p ≤ 0.05), and had the lowest distance for HI running (528 ± 39 m) in the backs. Running demands were similar for forwards and backs; however, within positions there was considerable variation, and the lower running measurements for outside backs maybe unique to women's rugby. Due to these findings and possible different tactical approaches, the development of training and speed zone bands specific to female players is advised because male research findings may lack transferability to women's rugby.

Senior Club-Level Rugby Union Player's Positional Movement Performance Using Individualized Velocity Thresholds and Accelerometer-Derived Impacts in Matches.

ABSTRACT: Takamori, S, Hamlin, MJ, Kieser, DC, King, D, Hume, P, Yamazaki, T, Hachiya, M, and Olsen, PD. Senior club-level rugby union player's positional movement performance using individualized velocity thresholds and accelerometer-derived impacts in matches. J Strength Cond Res 36(3): 710-716, 2022-Game demands of professional rugby union players have been well documented; however, there is minimal game demand information using individualized velocity thresholds and collision loads, particularly for amateurs. This study investigated movement patterns of 20 male amateur rugby players during 16 senior premier division one matches using global positioning system (GPS) devices sampling at 10 Hz. Derived GPS variables included distances, velocities, sprinting, and impacts. Data files from 86 player games (≥60 minutes of play per game) were categorized into broad (forwards and backs) and specific (front row, second row, back row, half back, inside back, and outside back) positional groups for analysis. It was most likely that backs covered more distance in the high-speed running (>60% maximal velocity) zone (502 ± 157 m) compared with forwards (238 ± 147 m) (100/0/0%, chances of positive/trivial/negative differences, effect size [ES] = 1.3), performed more striding (backs 1,116 ± 240, forwards 954 ± 240 m, 96/4/0%, ES = 0.5), and sprinting (backs 121 ± 58, forwards 90 ± 65 m, 93/7/0%, ES = 0.5). However, forwards had higher collision loads (35 ± 12 arbitrary units) compared with backs (20 ± 6, 99.9/0.1/0%, ES = 1.3) with back row forwards completing the highest collision load of any playing position (40 ± 13). Our example match movement performance and impact information is valuable to coaches and support staff in preparing player profiles for similar-level rugby players to help manage their workloads.

Short and long-term differences in anthropometric characteristics and physical performance between male rugby players that became professional or remained amateur.

OBJECTIVE: The objective of this study was to investigate which anthropometric and physical performance variables characterised players that advanced to professional teams (professionals) and how these variables changed over time, compared to those that did not secure professional contracts (i.e. remained amateurs). METHODS: Differences in anthropometry, strength, speed, power and intermittent running ability in 83 male rugby players collected between 2015 and 2019 were determined using repeated measures analysis. RESULTS: When arriving for the first year of the program, forwards that went on to become professional players were older (0.4 ± 0.3 yr, mean ± 95% CI, p = 0.004), heavier (4.6 ± 2.5 kg, p < 0.001) and stronger (range 6.2-16.4%) than forwards that remained amateur. Professional forwards were also slower at sprinting (range -2.7-2.9%, p < 0.001) and had lower Yo-Yo IRT L1 (-10.8%, p = 0.03). When first arrived on the program, professional backs were taller (3.5 ± 1.8 cm, p < 0.001), heavier (4.6 ± 2.4 kg, p < 0.001) and faster over 20 m (-1.9 ± 1.7%, p = 0.03) and 30 m (-1.7 ± 1.6%, p = 0.04) compared to amateurs. Compared to amateurs, professionals had a smaller increase in body mass (-4.2 ± 2.0%, p < 0.001) and greater improvement in sprinting (3.7, 2.8, 2.8% over 10, 20 and 30-m, respectively) and Yo-Yo IRT L1 (14.7 ± 11.0%, p = 0.05) over 3 years training. CONCLUSION: Characteristics that are likely to assist players in becoming professionals include being older, heavier, taller and stronger.

Fitness and Fatness Are Both Associated with Cardiometabolic Risk in Preadolescents.

OBJECTIVE: To determine the associations between cardiorespiratory fitness (CRF) and fatness (overweight-obesity) with cardiometabolic disease risk among preadolescent children. STUDY DESIGN: This cross-sectional study recruited 392 children (50% female, 8-10 years of age). Overweight-obesity was classified according to 2007 World Health Organization criteria for body mass index. High CRF was categorized as a maximum oxygen uptake, determined using a shuttle run test, exceeding 35 mL·kg-1·minute-1 in girls and 42 mL·kg-1·minute-1 in boys. Eleven traditional and novel cardiometabolic risk factors were measured including lipids, glucose, glycated hemoglobin, peripheral and central blood pressure, and arterial wave reflection. Factor analysis identified underlying cardiometabolic disease risk factors and a cardiometabolic disease risk summary score. Two-way analysis of covariance determined the associations between CRF and fatness with cardiometabolic disease risk factors. RESULTS: Factor analysis revealed four underlying factors: blood pressure, cholesterol, vascular health, and carbohydrate-metabolism. Only CRF was significantly (P = .001) associated with the blood pressure factor. Only fatness associated with vascular health (P = .010) and carbohydrate metabolism (P = .005) factors. For the cardiometabolic disease risk summary score, there was an interaction effect. High CRF was associated with decreased cardiometabolic disease risk in overweight-obese but not normal weight children (P = .006). Conversely, high fatness was associated with increased cardiometabolic disease risk in low fit but not high fit children (P < .001). CONCLUSIONS: In preadolescent children, CRF and fatness explain different components of cardiometabolic disease risk. However, high CRF may moderate the relationship between fatness and cardiometabolic disease risk. TRIAL REGISTRATION: ACTRN 12614000433606.

Hypoxic training improves blood pressure, nitric oxide and hypoxia-inducible factor-1 alpha in hypertensive patients.

PURPOSE: To examine the effects of intermittent hypoxic breathing at rest (IHR) or during exercise (IHT) on blood pressure and nitric oxide metabolites (NOx) and hypoxia-inducible factor-1 alpha levels (HIF-1α) over a 6-week period. METHODS: 47 hypertensive patients were randomly allocated to three groups: hypertensive control (CON: n = 17; IHR: n = 15 and IHT: n = 15. The CON received no intervention; whereas, IH groups received eight events of hypoxia (FIO2 0.14), and normoxia (FIO2 0.21), 24-min hypoxia and 24-min normoxia, for 6 weeks. The baseline data were collected 2 days before the intervention; while, the post-test data were collected at days 2 and 28 after the 6-week intervention. RESULTS: We observed a significant decrease of the SBP in both IH groups: IHR (- 12.0 ± 8.0 mmHg, p = 0.004 and - 9.9 ± 8.8 mmHg, p = 0.028, mean ± 95% CI) and IHT (- 13.0 ± 7.8 mmHg, p = 0.002 and - 10.0 ± 8.4 mmHg, p = 0.016) at days 2 and 28 post-intervention, respectively. Compared to CON, IHR and IHT had increased of NOx (IHR; 8.5 ± 7.6 µmol/L, p = 0.031 and IHT; 20.0 ± 9.1 µmol/L, p < 0.001) and HIF-1α (IHR; 170.0 ± 100.0 pg/mL, p = 0.002 and IHT; 340.5 ± 160.0 pg/mL, p < 0.001). At 2 days post-intervention, NOx and HIF-1α were negatively correlated with SBP in IHT. CONCLUSION: IH programs may act as an alternative therapeutic strategy for hypertension patients probably through elevation of NOx and HIF-1α production.

Validity and Reliability of the Hexoskin Wearable Biometric Vest During Maximal Aerobic Power Testing in Elite Cyclists.

Elliot, CA, Hamlin, MJ, and Lizamore, CA. Validity and reliability of the Hexoskin wearable biometric vest during maximal aerobic power testing in elite cyclists. J Strength Cond Res 33(5): 1437-1444, 2019-The purpose of this study was to investigate the validity and reliability of the Hexoskin vest for measuring respiration and heart rate (HR) in elite cyclists during a progressive test to exhaustion. Ten male elite cyclists (age 18-52 yrs, height 179.3 ± 6.0 cm, body mass 73.2 ± 9.1 kg, V[Combining Dot Above]O2max 60.7 ± 7.8 ml·kg·min, mean ± SD) conducted a maximal aerobic cycle ergometer test using a ramped protocol (starting at 100 W with 25 W increments each min to failure) during 2 separate occasions over a 3-4-day period. Compared with the criterion measure (MetaMax 3B) the Hexoskin vest showed mainly small typical errors (1.3-6.2%) for HR and breathing frequency (f), but larger typical errors (9.5-19.6%) for minute ventilation (V[Combining Dot Above]E) during the progressive test to exhaustion. The typical error indicating the reliability of the Hexoskin vest at moderate-intensity exercise between tests was small for HR (2.6-2.9%) and f (2.5-3.2%) but slightly larger for V[Combining Dot Above]E (5.3-7.9%). We conclude that the Hexoskin vest is sufficiently valid and reliable for measurements of HR and f in elite athletes during high-intensity cycling but the calculated V[Combining Dot Above]E value by the Hexoskin vest produced during such exercise should be used with caution because of the lower validity and reliability of this variable.

Living and Training at 825 m for 8 Weeks Supplemented With Intermittent Hypoxic Training at 3,000 m Improves Blood Parameters and Running Performance.

Wonnabussapawich, P, Hamlin, MJ, Lizamore, CA, Manimmanakorn, N, Leelayuwat, N, Tunkamnerdthai, O, Thuwakum, W, and Manimmanakorn, A. Living and training at 825 m for 8 weeks supplemented with intermittent hypoxic training at 3,000 m improves blood parameters and running performance. J Strength Cond Res 31(12): 3287-3294, 2017-We aimed to investigate the effect of an 8-week low-altitude training block supplemented with intermittent hypoxic training, on blood and performance parameters in soccer players. Forty university-level male soccer players were separated into altitude (n = 20, 825 m) or sea-level (n = 20, 125 m) groups. Before (1-2 days ago) and after (1 and 14 days later) training, players were asked to give a resting venous blood sample and complete a series of performance tests. Compared with sea level, the altitude group increased erythropoietin, red blood cell (RBC) count, and hematocrit 1 day after training (42.6 ± 24.0%, 1.8 ± 1.3%, 1.4 ± 1.1%, mean ± 95% confidence limits (CL), respectively). By 14 days after training, only RBC count and hemoglobin were substantially higher in the altitude compared with the sea-level group (3.2 ± 1.8%, 2.9 ± 2.1% respectively). Compared with sea level, the altitude group 1-2 days after training improved their 50-m (-2.9 ± 1.4%) and 2,800-m (-2.9 ± 4.4%) run times and demonstrated a higher maximal aerobic speed (4.7 ± 7.4%). These performance changes remained at 14 days after training with the addition of a likely higher estimated V[Combining Dot Above]O2max in the altitude compared with the sea-level group (3.2 ± 3.0%). Eight weeks of low-altitude training, supplemented with regular bouts of intermittent hypoxic training at higher altitude, produced beneficial performance improvements in team-sport athletes, which may increase the viability of such training to coaches and players that cannot access more traditional high altitude venues.

Effects of elastic taping, non-elastic taping and static stretching on recovery after intensive eccentric exercise.

The purpose of this study was to compare the effect of elastic tape (Kinesio tape) to placebo tape or static stretching on delayed onset muscle soreness. Fifty-one untrained female healthy volunteers were randomly assigned into three groups (n = 17/group), elastic tape, placebo tape and stretching group. Muscle soreness was induced by 4 sets of 25 maximal isokinetic (60°.s-1) eccentric contractions of dominant quadriceps on an isokinetic dynamometer. Compared with placebo tape, the elastic tape participants had less muscle soreness at 72 h post-exercise (p = 0.01). The elastic tape also increased isometric strength at 72 h post-exercise compared with the placebo (p = 0.03) and stretching group (p = 0.02). However, there was little effect between groups for changes in thigh circumference, jumping, pressure pain threshold, rate of perceived exertion, creatine kinase activity and joint motion. Elastic taping increased muscle strength recovery and reduced muscle soreness after intensive exercise.

Effects of Whole Body Vibration on Glycemic Indices and Peripheral Blood Flow in Type II Diabetic Patients.

BACKGROUND: Whole body vibration (WBV) training is a regime of training on a vibration platform that provides oscillatory movement to the body. Vibration training may be a potentially useful therapeutic strategy to control diabetes and its complications. This study aimed to evaluate the effect of WBV on glycemic indices and peripheral blood flow in type II diabetic patients. METHODS: A parallel group clinical trial was conducted with 1:1 allocation ratio at Khon Kaen University between February and May 2010. The study included diabetic patients receiving diet or oral medication control over the previous year and excluded patients with serious medical and musculoskeletal disorders. Forty type II diabetic patients [14 males, 26 females, 63.2 (7.7) y, mean (SD)] were randomised into two groups (WBV and control) by computer software using a block of four design. The WBV group was given two sets of six one-minute vibration squats, three times per week for twelve weeks. The control group maintained their normal physical activity levels. The primary outcome was the patients glycemic indices. RESULTS: We found no significant difference in glycosylated haemoglobin (HbA1c), fasting blood sugar, insulin level and insulin sensitivity between WBV and control groups. Compared to the control group, WBV training resulted in a substantial reduction in resting diastolic blood pressure -7.1 mmHg (95% CI: -10.9, -3.3, P = 0.001) and peak systolic velocity -7.3 cm.sec-1 (95% CI: -14.7, -0.03, P = 0.049), but made little difference to resting heart rate, systolic blood pressure, end diastolic velocity, and popliteal artery diameter. CONCLUSION: Whole body vibration improved resting diastolic blood pressure and peak systolic velocity, however, any beneficial effect of WBV on glycemic indices remains unclear.

The Effect of Altitude and Travel on Rugby Union Performance: Analysis of the 2012 Super Rugby Competition.

The aim of this study was to investigate whether playing rugby at altitude or after travel (domestic and international) disadvantaged teams. In a retrospective longitudinal study, all matches (N = 125) played in the 2012 Super Rugby Competition were analyzed for key performance indicators (KPI) from coded game data provided by OPTA sports data company. Matches were played in a home-away format in New Zealand, South Africa, and Australia. Teams based at sea level but playing at altitude (1,271-1,753 m) were more likely to miss tackles (mean ± 90% confidence interval, 1.4 ± 1.7) and score fewer points in the first half compared with games at sea level. In the second half of games, sea level teams at altitude were very likely to make fewer gain lines (-4.0 ± 2.7) compared with the second half of games at sea level. The decreased ability to break the defensive line, which may be the result of altitude-induced fatigue, could reduce the likelihood of scoring points and winning a game. Travel also had an effect on KPI, where international travel resulted in more missed tackles (1.7 ± 1.3) and less frequent gain lines (-3.0 ± 1.9) in the first half relative to matches at home; overall, away teams (domestic and international) scored 4 less points in the second half compared with home teams. In conclusion, playing away from home in another country, particularly at altitude, can have a detrimental effect on KPI, which may affect the overall performance and the chances of winning matches.

Long-term effect of whole body vibration training on jump height: meta-analysis.

Whole body vibration (WBV) is widely promoted as a means of improving muscle strength, but the evidence of a performance benefit is unclear with some reporting improvements and others finding none. The objective of this study was to analyze the current evidence for the effectiveness of WBV on jump height. We included randomized controlled trials or matched design studies comparing the effect of WBV training on countermovement and squat jump (SJ) height, which were gathered from MEDLINE, Web of Knowledge, Sciencedirect, Proquest, Scopus, Google Scholar, and SPORTDiscus databases. The overall effect of WBV training (from the 15 studies included) compared with having no additional exercise on countermovement jump height yielded a positive standardized mean difference of 0.77 (95% confidence interval, 0.55-0.99). The effect of WBV training on SJ height was 0.68 (0.08-1.11). Vibration exercise consisting of a higher frequency (>30 Hz, 0.86, 0.62-1.10), higher amplitude (>3 mm, 0.84, 0.52-1.17), longer exposure duration (>10 minutes per session, 0.92, 0.48-1.36), longer training period (>12 weeks, 0.87, 0.56-1.19) and among nonathletes (0.96, 0.63-1.30) had greater benefit for jump height improvement than a lower frequency (≤ 30 Hz, 0.56, 0.13-0.99), lower amplitude (≤ 3 mm, 0.66, 0.35-0.98), shorter exposure duration (≤ 10 minutes per session, 0.68, 0.45-0.92), intermediate training period (4-12 weeks, 0.72, 0.35-1.09), shorter training period (<4 weeks, 0.58, -0.08 to -1.23) and in athletes (0.59, 0.31-0.88). The effect of WBV training compared with a standard cardiovascular-type exercise group from 4 studies was 0.63 (0.10-1.15). In conclusion, WBV training produces a moderate-to-large effect on jump height. Vibration training protocols with higher frequencies, higher amplitudes, longer exposures per session, and longer training periods are more likely to enhance muscle power.

Effects of elastic taping on kyphosis and body balance in the elderly: a randomized crossover study.

Kyphosis produces abnormal posture and reduced body balance in the elderly. Elastic tape may be useful at improving kyphotic posture and body balance. This study aims to evaluate the effects of elastic taping on kyphosis and body balance in the elderly. Ten elderly participants with degenerative kyphotic posture were recruited and randomly assigned to two groups (back taped with stretched elastic tape for 15 min and back taped with non-stretched elastic tape for 15 min). After a 1-h washout period, the groups were swapped over to receive the other intervention. The outcomes measured after each taping technique were Cobb's angle measurement by inclinometer, perceived pain, and balance measurements by single leg stance test, time up and go test, center of gravity alignment (COG) and modified clinical test of sensory interaction on balance test (mCTSIB). There was a significant reduction in kyphotic angle and back pain in both the stretched and non-stretched taping groups (p < 0.05). We also found both taping techniques significantly reduced sway velocity on a foam surface with eyes closed and open (p < 0.05). However, there was no significant difference between taping groups for kyphotic angle, pain reduction or balance. The application of 15 min of stretched and non-stretched elastic tape in the elderly reduced kyphotic angle, back pain, and sway velocity while standing on foam surface in the mCTSIB test. If these changes persist over the long term (days and weeks) taping may be a useful intervention for elderly patients with kyphosis.

Effects of resistance training combined with vascular occlusion or hypoxia on neuromuscular function in athletes.

The aim was to investigate the effects of low-load resistant training combined with vascular occlusion or normobaric hypoxic exposure, on neuromuscular function. In a randomised controlled trial, well-trained athletes took part in a 5-week training of knee flexor/extensor muscles in which low-load resistant exercise (20% of one repetition maximum, 1-RM) was combined with either (1) an occlusion pressure of approximately 230 mmHg (KT, n = 10), (2) hypoxic air to generate an arterial blood oxygen saturation of ~80% (HT, n = 10), or (3) with no additional stimulus (CT, n = 10). Before and after training, participants completed the following tests: 3-s maximal voluntary contraction (MVC3), 30-s MVC, and an endurance test (maximal number of repetitions at 20% 1-RM, Reps20). Electromyographic activity (root mean square, RMS) was measured during tests and the cross-sectional area (CSA) of the quadriceps and hamstrings was measured pre- and post-training. Relative to CT, KT, and HT showed likely increases in MVC3 (11.0 ± 11.9 and 15.0 ± 13.1%, mean ± 90% confidence interval), MVC30 (10.2 ± 9.0 and 18.3 ± 17.4%), and Reps20 (28.9 ± 23.7 and 23.3 ± 24.0%). Compared to the CT group, CSA increased in the KT (7.6 ± 5.8) and HT groups (5.3 ± 3.0). KT had a large effect on RMS during MVC3, compared to CT (effect size 0.8) and HT (effect size 0.8). We suspect hypoxic conditions created within the muscles during vascular occlusion and hypoxic training may play a key role in these performance enhancements.

Physical activity has a stronger correlation with arterial stiffness than strength, balance, or BMI in an older population.

Background: Arterial stiffness is associated with an array of debilitating health conditions. While exercise typically has beneficial effects on both arterial stiffness and overall health, more research is needed to understand the associations of different types of fitness indices with arterial stiffness. Aim: To investigate the relationship between balance, strength, cardiovascular fitness and physical activity with arterial stiffness (as measured by pulse wave velocity (PWV)) in older adults. Method: Eighty retirement-village residents (24 males, 56 females, age: 78.2 ± 6.4 years, weight: 69.4 ± 12.5 kg, height: 162.9 ± 8.5 cm) completed the Yale Physical Activity Survey, PWV measurement, 30-s sit-to-stand leg strength test, hand grip strength assessment, 4-stage balance test, and a 6-min walk fitness test. The number of exiting risk factors (smoking, previous heart incidents, previous stroke(s), having hypertension, or taking anti-hypertension medication) were tallied. Pearson's correlations were used to assess the relationship between PWV and health and fitness parameters. Results were interpreted using qualitative inference. Results: The number of risk factors (r = 0.57, p < 0.001), age (r = 0.51, p < 0.001) and systolic blood pressure (r = 0.50, p = 0.001) had strong, harmful associations with PWV. Total physical activity minutes/week (r = -0.31 p = 0.01), total energy expenditure Kcal/week (r = -0.30, p = 0.01), and the 6-min walk test (r = -0.29, p = 0.01) had a moderate, beneficial association with PWV, while sit-to-stand (r = -0.27, p = 0.02) and balance (r = -0.27, p = 0.01) had a weak, beneficial association with PWV. Hand grip strength (r = 0.02, p = 0.94) and body mass index (r = -0.04, p = 0.75) had no significant associations with PWV. Discussion: All measured fitness indices had beneficial associations with PWV. However, having more risk factors, increased age, and higher systolic blood pressure had significant (harmful) associations with PWV in our older population. Conclusion: Controlling cardiovascular risk factors, especially high systolic blood pressure, is likely to have the largest beneficial effect on PWV. Improving general physical activity, including walking capacity, may prove beneficial in improving PWV in an older population.

Association between Yoga Participation and Arterial Stiffness: A Cross-Sectional Study.

BACKGROUND: Yoga may help adults of all fitness levels increase their physical activity and decrease their cardiovascular disease risk. AIM: To determine if arterial stiffness is lower (beneficial) in yoga versus non-yoga participants. METHOD: This cross-sectional study included 202 yoga (48.4 + 14.1 years, 81% female) and 181 (42.8 + 14.1 years, 44% female) non-yoga participants. The primary outcome was carotid-femoral pulse wave velocity (cfPWV). The two groups were compared using analysis of covariance with adjustments for demographic (age and sex), hemodynamic (mean arterial pressure and heart rate), lifestyle (physical activity levels, sedentary behaviour, smoking status and perceived stress score) and cardiometabolic (waist-to-hip ratio, total cholesterol and fasting glucose) factors. RESULTS: Following adjustments, cfPWV was significantly lower in yoga compared to non-yoga participants with a mean difference: -0.28 m.s-1, (95% CI = -0.55 to 0.08). CONCLUSION: At a population level, yoga participation may assist with decreasing the risk of cardiovascular disease in adults.

A Cross-Sectional Investigation of Preadolescent Cardiometabolic Health: Associations with Fitness, Physical Activity, Sedentary Behavior, Nutrition, and Sleep.

BACKGROUND: Cardiometabolic disease (CMD) risk often begins early in life. Healthy lifestyle behaviors can mitigate risk, but the optimal combination of behaviors has not been determined. This cross-sectional study simultaneously examined the associations between lifestyle factors (fitness, activity behaviors, and dietary patterns) and CMD risk in preadolescent children. METHODS: 1480 New Zealand children aged 8-10 years were recruited. Participants included 316 preadolescents (50% female, age: 9.5 ± 1.1 years, BMI: 17.9 ± 3.3 kg/m2). Fitness (cardiorespiratory fitness [CRF], muscular fitness), activity behaviors (physical activity, sedentary, sleep), and dietary patterns were measured. Factor analysis was used to derive a CMD risk score from 13 variables (adiposity, peripheral and central hemodynamics, glycemic control, and blood lipids). RESULTS: Only CRF (ß = -0.45, p < 0.001) and sedentary time (ß = 0.12, p = 0.019) were associated with the CMD risk score in the adjusted multivariable analysis. CRF was found to be nonlinear (VO2 max ≤ ≈42 mL/kg/min associated with higher CMD risk score), and thus a CRF polynomial term was added, which was also associated (ß = 0.19, p < 0.001) with the CMD risk score. Significant associations were not found with sleep or dietary variables. CONCLUSION: The findings indicate that increasing CRF and decreasing sedentary behavior may be important public health targets in preadolescent children.

Positive effect of lower body compression garments on subsequent 40-kM cycling time trial performance.

This study aimed to investigate the effect of wearing graduated compression garments during recovery on subsequent 40-km time trial performance. In a randomized single-blind crossover experiment, 14 trained multisport male athletes (mean ± SD: age 33.8 ± 6.8 years, 40-km time 66:11 ± 2:10 minutes:seconds) were given a graduated full-leg-length compressive garment (76% Meryl Elastane, 24% Lycra) or a similar-looking noncompressive placebo garment (92% Polyester, 8% Spandex) to wear continuously for 24 hours after performing an initial 40-km time trial in their normal cycling attire. After the 24-hour recovery period, the compression (or placebo) garments were removed, and a second 40-km time trial was then completed to gauge the effect of each garment on subsequent performance. One week later, the groups were reversed and testing procedures repeated. The participant's hydration status, nutritional intake, and training were similar before each set of trials. Performance time in the second time trial was substantially improved with compression compared with placebo garments (1.2 ± 0.4%, mean ± 90% confidence interval). This improvement resulted in a substantially higher average power output after wearing the compression garment compared with that after wearing the placebo garment (3.3 ± 1.1%). Differences in oxygen cost and rating of perceived exertion between groups were trivial or unclear. The wearing of graduated compressive garments during recovery is likely to be worthwhile and unlikely to be harmful for well-trained endurance athletes.

Effect of compression garments on short-term recovery of repeated sprint and 3-km running performance in rugby union players.

The aim of this study was to investigate whether wearing compression garments during recovery improved subsequent repeated sprint and 3-km run performance. In a randomized single-blind crossover study, 22 well-trained male rugby union players (mean ± SD: age 20.1 ± 2.1 years, body mass 88.4 ± 8.8 kg) were given a full-leg length compressive garment (76% Meryl Elastane, 24% Lycra) or a similar-looking noncompressive placebo garment (92% Polyamide, 8% Lycra) to wear continuously for 24 hours after performing a series of circuits developed to simulate a rugby game. After the 24-hour recovery, garments were removed and a 40-m repeated sprint test (10 sprints at 30-second intervals), followed 10 minutes later by a 3-km run, was completed. One week later, the groups were reversed and testing repeated. Relative to the placebo, wearing the compressive garment decreased time to complete the 3 km by 2.0% ± 1.9% (mean ± 90% confidence interval). Additionally, average sprint times improved (1.2% ± 1.5%) and fatigue was diminished (-15.8% ± 26.1%) during the repeated sprint test in the compression group compared with the placebo group. Delayed onset muscle soreness was substantially lower in the compression group compared with the placebo group, 48 hours after testing. Wearing compressive garments during recovery is likely to be worthwhile, and very unlikely to be harmful for well-trained rugby union players.

Does intermittent hypoxic exposure enhance the cardioprotective effect of exercise in an inactive population?

The aim of this study was to determine whether exercise supplemented with passive intermittent hypoxic exposure (IHE) improved overall cardiovascular disease risk and individual risk factors. Participants were randomized to exercise-only (Ex, n = 18, 5 males, 13 females; age: 56.4 ± 6.5 years; weight: 81.2 ± 15.9; height: 167.3 ± 8.42) or exercise + IHE (IHE + Ex, n = 16; 6 males, 10 females; age: 56.7 ± 6.4 years; weight: 78.6 ± 12.4 kg; height: 168.0 ± 8.8 cm). Both groups received the same strength and aerobic exercise training (1 h, 3 days/wk, 10 weeks). IHE + Ex also received IHE (5 min hypoxia: 5 min ambient air ×6) for 2-3 days/wk. Measurements were collected before (Baseline), after (Post), and 4- and 8-week following the intervention. There were small, beneficial reductions in overall 5- year cardiovascular risk in both groups. At Post, for IHE + Ex compared to IHE there were unclear to likely improvements in high density lipoprotein (8.0% ± 8.0%), systolic blood pressure (-3.4% ± 3.4%) and VO2peak (3.1% ± 7.7%). These improvements persisted at 8-week. There was an unclear improvement in arterial wave reflection (augmentation index) at Post (-6.1% ± 18.4%, unclear), but became very likely harmful at 8-week (8-week: 24.8% ± 19.7%). The conflicting findings indicate that in inactive adults, the addition of IHE to exercise may be beneficial to systemic markers of cardiovascular health but may also increase myocardial load due to increased arterial wave reflection.