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Face masks are promoted for preventing spread of viruses; however, wearing a mask during exercise might increase CO 2 rebreathing, decrease arterial oxygenation, and decrease exercise performance. A systematic review and meta-analysis was conducted on the impact of wearing a mask during exercise. Data sources included SPORTDiscus, PubMed, and Medline. Eligibility criteria included all study designs comparing surgical, N95, or cloth masks to a no mask condition during any type of exercise where exercise performance and/or physiological parameters were evaluated. Healthy and clinical participants were included. Mean differences (MD) or standardized mean differences (SMD) with 95% confidence intervals were calculated and pooled effects assessed. Twenty-two studies involving 1573 participants (620 females, 953 males) were included. Surgical, or N95 masks did not impact exercise performance (SMD -0.05 [-0.16, 0.07] and -0.16 [-0.54, 0.22], respectively) but increased ratings of perceived exertion (SMD 0.33 [0.09, 0.58] and 0.61 [0.23, 0.99]) and dyspnea (SMD 0.6 [0.3, 0.9] for all masks). End-tidal CO 2 (MD 3.3 [1.0, 5.6] and 3.7 [3.0, 4.4] mm Hg), and heart rate (MD 2 [0,4] beats/min with N95 masks) slightly increased. Face masks can be worn during exercise with no influences on performance and minimal impacts on physiological variables. PROSPERO registration: CRD42020224988. Novelty: Face masks can be worn during exercise with no impacts on performance and minimal impacts on physiological variables.

Newcomers are often healthy when they arrive in Canada, yet experience health declines shortly thereafter, possibly due to lifestyle changes. As part of the Healthy Immigrant Children study, this mixed-methods study aims to analyze possible predictors of physical activity among 300 newcomer children, and explore their lived experiences using a sub-sample of 19 parents and 24 service providers. Data collection involved questionnaires concerning socioeconomic status and physical activity, anthropometric measurements, and in-depth interviews. Participants aged 5 years and older largely met physical activity recommendations (82.9%), while none of the 3-4-year-olds did. Males were more active than females, especially among older ages. Many participants engaged in too much screen time (53.4-90.0%). Age and income predicted physical activity among males, while parents' education level was the only significant predictor among females. Barriers to physical activity included: recreational physical activity being an unfamiliar concept, gender limitations, financial resources, safety concerns, and children's preference for screen time. Schools played a central role in newcomer children's health by providing accessible opportunities for physical activity. Newcomer families preferred to have their children involved in culturally relevant physical activities. Given the growing newcomer population, it is important to support active lifestyle practices among them. Novelty: About 83% of newcomer children aged 5 years and older met physical activity recommendations, while none of the 3-4-year-olds did. Age and income predicted males' physical activity, while parents' education level predicted females' physical activity. Schools provide accessible opportunities for newcomer children to engage in physical activity.

University students are a vulnerable group for poor dietary intake, insufficient physical activity and sedentary behaviour. The purpose of this study was to examine the impact of coronavirus disease (COVID-19) on university students' dietary intake, physical activity, and sedentary behaviour. Participants were students ( n = 125) from the Universities of Saskatchewan and Regina. An online questionnaire was administered retrospectively (for prepandemic) and prospectively (during the pandemic) to examine students' dietary intake, physical activity, and sedentary behaviour. Overall, nutrient and caloric intakes were significantly reduced ( p < 0.05) during the pandemic, and alcohol intake increased ( p = 0.03). Before the pandemic, 16% and 54% of the participants were meeting the Canadian 24-Hour Movement Guidelines for Adults (18-64 years) of 150 min of moderate-vigorous physical activity and 8 h or less of sedentary activity, respectively. Only 10% met the guidelines for physical activity while 30% met the guidelines for sedentary behaviour during the pandemic. The minutes per week spent engaging in moderate to vigorous physical activity during the pandemic decreased by approximately 20% ( p < 0.001). The hours spent in sedentary activities increased by 3 h per day ( p < 0.001). Our findings confirm that during the pandemic, students' inadequate dietary intake, high alcohol consumption, low physical activity, and high sedentary behaviour were significantly compounded. Novelty: During COVID-19, the nutrient and caloric intakes of university students decreased, and alcohol intake increased significantly. University students' physical activity levels decreased, and sedentary activity increased significantly during COVID-19. During COVID-19 students did not engage in sufficient physical activity to offset the increased sedentary behaviour.

Background: Aerobic exercise is recommended for reducing blood pressure; however, recent studies indicate that stretching may also be effective. The authors compared 8 weeks of stretching versus walking exercise in men and women with high-normal blood pressure or stage 1 hypertension (ie, 130/85-159/99 mm Hg)., Methods: Forty men and women (61.6 y) were randomized to a stretching or brisk walking exercise program (30 min/d, 5 d/wk for 8 wk). Blood pressure was assessed during sitting and supine positions and for 24 hours using a portable monitor before and after the training programs., Results: The stretching program elicited greater reductions than the walking program (P < .05) for sitting systolic (146 [9] to 140 [12] vs 139 [9] to 142 [12] mm Hg), supine diastolic (85 [7] to 78 [8] vs 81 [7] to 82 [7] mm Hg), and nighttime diastolic (67 [8] to 65 [10] vs 68 [8] to 73 [12] mm Hg) blood pressures. The stretching program elicited greater reductions than the walking program (P < .05) for mean arterial pressure assessed in sitting (108 [7] to 103 [6] vs 105 [6] vs 105 [8] mm Hg), supine (102 [9] to 96 [9] vs 99 [6] to 99 [7] mm Hg), and at night (86 [9] to 83 [10] vs 88 [9] to 93 [12] mm Hg)., Conclusions: An 8-week stretching program was superior to brisk walking for reducing blood pressure in individuals with high-normal blood pressure or stage 1 hypertension.

Wearing face masks is recommended for the prevention of contracting or exposing others to cardiorespiratory infections, such as COVID-19. Controversy exists on whether wearing face masks during vigorous exercise affects performance. We used a randomized, counterbalanced cross-over design to evaluate the effects of wearing a surgical mask, a cloth mask, or no mask in 14 participants (7 men and 7 women; 28.2 ± 8.7 y) during a cycle ergometry test to exhaustion. Arterial oxygen saturation (pulse oximetry) and tissue oxygenation index (indicator of hemoglobin saturation/desaturation) at vastus lateralis (near-infrared spectroscopy) were assessed throughout the exercise tests. Wearing face masks had no effect on performance (time to exhaustion (mean ± SD): no mask 622 ± 141 s, surgical mask 657 ± 158 s, cloth mask 637 ± 153 s ( p = 0.20); peak power: no mask 234 ± 56 W, surgical mask 241 ± 57 W, cloth mask 241 ± 51 W ( p = 0.49)). When expressed relative to peak exercise performance, no differences were evident between wearing or not wearing a mask for arterial oxygen saturation, tissue oxygenation index, rating of perceived exertion, or heart rate at any time during the exercise tests. Wearing a face mask during vigorous exercise had no discernable detrimental effect on blood or muscle oxygenation, and exercise performance in young, healthy participants (ClinicalTrials.gov, NCT04557605).

We determined the effect of consuming low-glycemic index (LGI) skim milk compared to a high-glycemic index (HGI) sports drink following evening exercise on fat oxidation and blood lipids after a subsequent high-energy breakfast. We hypothesized that postexercise skim milk consumption, compared to sports drink, would increase fat oxidation and lower harmful blood lipid and glucose concentrations after a next-day high-energy breakfast. In this randomized counterbalanced crossover trial, 20 overweight-obese participants (body mass index ≥ 25 kg/m 2 ) underwent 4 conditions: 90-minute exercise (50% Vo 2peak ) followed by sports drink (EX-HGI), exercise followed by isoenergetic skim milk (EX-LGI), exercise followed by water (Exercise), and a control condition (Control). The amount of the sports drink or milk consumed postexercise was based on the energy used during exercise plus 10%. Blood lipids, glucose, and fat oxidation were assessed before and for 6 hours after a high-energy breakfast the next morning. Fat oxidation was highest for EX-LGI (6.7 ± 2.7 g/h) and lowest for EX-HGI (6.0 ± 1.8 g/h) (condition main effect; P = .042). Triglyceride concentration and total area under the curve were higher with EX-HGI than Exercise (1.7 ± 1.6 vs 1.3 ± 1.0 mmol/L, P = .037, and 11.7 ± 9.4 vs 8.6 ± 6.0 mmol L -1  h, P = .005, respectively). Glucose concentration was lower with EX-LGI than EX-HGI (4.1 ± 1.1 vs 4.4 ± 1.1 mmol/L, P = .027). Homeostatic model assessment of insulin resistance was higher with EX-HGI than Control (2.32 ± 1.15 vs 1.86 ± 0.97, P = .005). In conclusion, evening postexercise skim milk consumption, compared with a high-GI sports drink, significantly reduced blood glucose and possibly increased fat oxidation after a high-energy breakfast the next morning., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose of Review: The age-related loss of skeletal muscle and bone tissue decreases functionality and increases the risk for falls and injuries. One contributing factor of muscle and bone loss over time is chronic low-grade inflammation. Exercise training is an effective countermeasure for decreasing the loss of muscle and bone tissue, possibly by enhancing immune system response. Herein, we discuss key interactions between the immune system, muscle, and bone in relation to exercise perturbations, and we identify that there is substantial "cross-talk" between muscle and bone and the immune system in response to exercise., Recent Findings: Recent advances in our understanding of the "cross-talk" between muscle and bone and the immune system indicate that exercise is likely to mediate many of the beneficial effects on muscle and bone via their interactions with the immune system. The age-related loss of muscle and bone tissue may be partially explained by an impaired immune system via chronic low-grade inflammation. Exercise training has a beneficial effect on immune system function and aging muscle and bone. Theoretically, the "cross-talk" between the immune system, muscle, and bone in response to exercise enhances aging musculoskeletal health.

This Horizons is part of a series that identifies key, forward-thinking research questions and challenges that need to be addressed. Specifically, this Horizons paper discusses research in nutritional supplements and nutraceuticals for health, physical activity, and performance, and is the product of a discussion by an expert panel that took place in January 2018 prior to the Canadian Nutrition Society Thematic Conference "Advances in Sport Nutrition from Daily Living to High Performance Sport". The objective of this Horizons paper was to identify core considerations for future studies for this research area, and how scientists can be leaders in the field to ensure the best quality science is available for decision makers. It is strongly recommended that the various elements highlighted throughout this Horizons paper will increase the awareness of the significant before-, during-, and after-research due-diligence required to produce research of the highest quality. While it is recognized that many scientists will not be able to meet all of these aspects, it is nonetheless important to consider the points outlined and to recognize that those elements that are not met in studies may be significant limitations. Highlights Research questions that are hypothesis-driven are the strongest, and when combined with careful planning of the study, the result will often be of the best quality. Studies with a strong experimental design help discern between evidence-based findings and those that have not been substantiated.

We compared the effects of a low-glycemic index pulse-based diet, containing lentils, beans, split peas, and chickpeas, to the Therapeutic Lifestyle Changes (TLC) diet on cardio-metabolic measures in women with polycystic ovary syndrome (PCOS). Ninety-five women (18⁻35 years) enrolled in a 16-week intervention; 30 women in the pulse-based and 31 in the TLC groups completed the study. Women participated in aerobic exercise training (minimum 5 days/week for 45 min/day) and were counselled (monthly) about PCOS and lifestyle modification. Women underwent longitudinal follow-up post-intervention. The pulse-based group had a greater reduction in total area under the curve for insulin response to a 75-g oral glucose tolerance test (mean change ± SD: -121.0 ± 229.9 vs. -27.4 ± 110.2 µIU/mL × min; p = 0.05); diastolic blood pressure (-3.6 ± 6.7 vs. -0.2 ± 6.7 mmHg, p = 0.05); triglyceride (-0.2 ± 0.6 vs. 0.0 ± 0.5 mmol/L, p = 0.04); low-density lipoprotein cholesterol (-0.2 ± 0.4 vs. -0.1 ± 0.4 mmol/L, p = 0.05); total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C; -0.4 ± 0.4 vs. 0.1 ± 0.4, p < 0.001); and a greater increase in HDL-C (0.1 ± 0.2 vs. -0.1 ± 0.2 mmol/L, p < 0.01) than the TLC group. Decreased TC/HDL-C ( p = 0.02) at six-month and increased HDL-C and decreased TC/HDL-C ( p ≤ 0.02) at 12-month post-intervention were maintained in the pulse-based group. A pulse-based diet may be more effective than the TLC diet at improving cardio-metabolic disease risk factors in women with PCOS., Trial Registration: CinicalTrials.gov identifier, NCT01288638.

A bout of eccentric exercise (ECC) has the protective effect of reducing muscle damage during a subsequent bout of ECC known as the "repeated bout effect" (RBE). The purpose of this study was to determine if the RBE is greater when both bouts of ECC are performed using the same vs. different velocity of contraction. Thirty-one right-handed participants were randomly assigned to perform an initial bout of either fast (3.14 rad·s [180°·s]) or slow (0.52 rad·s [30°·s]) maximal isokinetic ECCs of the elbow flexors. Three weeks later, the participants completed another bout of ECC at the same velocity (n = 16), or at a different velocity (n = 15). Indirect muscle damage markers were measured before, immediately after, and at 24, 48, and 72 hours postexercise. Measures included maximal voluntary isometric contraction (MVC) strength (dynamometer), muscle thickness (MT; ultrasound), delayed onset muscle soreness (DOMS; visual analog scale), biceps and triceps muscle activation amplitude (electromyography), voluntary activation (interpolated twitch), and twitch torque. After the repeated bout, MVC strength recovered faster compared with the same time points after the initial bout for only the same velocity group (p = 0.017), with no differences for all the other variables. Irrespective of velocity, MT and DOMS were reduced after the repeated bout compared with that of the initial bout at 24, 48, and 72 hours with a corresponding increase in TT at 72 hours (p < 0.05). Faster recovery of isometric strength associated with a repeated bout of ECC was evident when the velocity was matched between bouts, suggesting that specificity effects contribute to the RBE. The current findings support the idea of multiple mechanisms contributing to the RBE.

We determined the effects of 2 years of exercise training and soy isoflavone supplementation on bone mass and lipids in postmenopausal women provided with calcium and vitamin D. Women were randomized to four groups: exercise training (Ex); isoflavone supplementation (Iso: 165 mg/d [105 mg/d aglycone equivalent]); combined Ex and Iso (ExIso); and placebo (control). Exercise included resistance training (2 days/week) and walking (4 days/week). Our primary outcomes were lumbar spine and hip bone mineral density (BMD). Secondary outcomes included hip geometry, tibia and radius speed of sound (SOS), dynamic balance (6 m backward tandem walking), blood lipids, mammography, and endometrial thickness. A total of 351 women (Ex = 86, Iso = 90, ExIso = 87, control = 88) were randomized, with 298 analyzed at 2 years (Ex = 77, Iso = 76, ExIso = 72, control = 73). There was a significant interaction for total hip BMD (p < 0.001) such that ExIso had a greater rate of decrease (absolute change [95% confidence interval] = -0.018 [-0.024, -0.012] g/cm(2) ) than either the Ex or Iso groups alone (-0.005 [-0.01, 0.001] and -0.005 [-0.011, 0.001] g/cm(2) , respectively). There were no differences between groups for changes in lumbar spine BMD and minimal significant changes in hip geometric properties and bone SOS. Exercise groups improved dynamic balance as measured by a decrease in backward tandem walking time over 6 m (p = 0.017). Isoflavone groups decreased low density lipoproteins (Iso: -0.20 [-0.37, -0.02] mmol/L; ExIso: -0.23 [-0.40, -0.06] mmol/L; p = 0.003) compared to non-isoflavone groups (Ex: 0.01 [-0.16, 0.18] mmol/L; control: -0.09 [-0.27, 0.08] mmol/L) and had lower adverse reports of menopausal symptoms (14% versus 33%; p = 0.01) compared to non-isoflavone groups. Isoflavone supplementation did not increase endometrial thickness or abnormal mammograms. We conclude exercise training and isoflavone supplementation maintain hip BMD compared to control, but these two interventions interfere with each other when combined. Isoflavone supplementation decreased LDL and adverse events related to menopausal symptoms., (Copyright © 2013 American Society for Bone and Mineral Research.)

The metabolic and performance benefits of prior consumption of low-glycaemic index (GI) meals v. high-GI meals were determined in extended high-intensity intermittent exercise. Participants (ten males and four females, aged 25·8 (sd 7·3) years) completed two testing days (each consisting of back-to-back 90-min intermittent high-intensity treadmill running protocols separated by 3 h) spaced by at least 7 d. Using a randomised counterbalanced cross-over design, low-GI, lentil-based meals (GI about 42) or high-GI, potato-based meals (GI about 78) matched for energy value were consumed 2 h before, and within 1 h after, the first exercise session. Performance was measured by the distance covered during five 1-min sprints (separated by 2·5 min walking) at the end of each exercise session. Peak postprandial blood glucose was higher by 30·8 % in the high-GI trial compared with the low-GI trial, as was insulin (P = 0·039 and P = 0·003, respectively). Carbohydrate oxidation was lower by 5·5 % during the low-GI trials compared with the high-GI trials at the start of the first exercise session (P < 0·05). Blood lactate was significantly higher (6·1 v. 2·6 mmol/l; P = 0·019) and blood glucose significantly lower (4·8 v. 5·4 mmol/l; P = 0·039) at the end of the second exercise session during the high-GI trial compared with the low-GI trial. Sprint distance was not significantly different between conditions. A low-GI meal improved the metabolic profile before and during extended high-intensity intermittent exercise, but did not affect performance. Improvements in metabolic responses when consuming low-GI meals before exercise may be beneficial to the long-term health of athletes.

To examine developmental trajectories of trunk fat mass (FM) growth of individuals categorized as either low or high for cardiometabolic risk at 26 years, a total of 55 males and 76 females from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2007) were assessed from adolescence (11.5 ± 1.8 years) to young adulthood (26.2 ± 2.2 years) (median of 11 visits per individual) and had a measure of cardiometabolic risk in young adulthood. Participants were categorized as low or high for blood pressure and cardiometabolic risk as adults using a sex-specific median split of continuous standardized risk scores. Individual trunk FM trajectories of participants in each risk group were analyzed using multilevel random effects models. Males and females in the high blood pressure group had significantly steeper (accelerated) trajectories of trunk FM development (0.61 ± 0.14 and 0.52 ± 0.10 log g, respectively) than those in the low blood pressure group for females in the high cardiometabolic risk group trajectory of trunk FM was significantly steeper (0.52 ± 0.10 log g) than those females in the low cardiometabolic risk group. Dietary fat was positively related (0.01 ± 0.003 g/1,000 kcal) and physical activity negatively related (-0.16 ± 0.05 physical activity score) to trunk FM development in males. Young adults with high cardiometabolic risk, compared to low, have greater trunk FM as early as 8 years of age, which supports the need for early intervention.

Consuming carbohydrate-rich meals before continuous endurance exercise improves performance, yet few studies have evaluated the ideal preexercise meal for high-intensity intermittent exercise, which is characteristic of many team sports. The authors' purpose was to investigate the effects of low- and high-glycemic-index (GI) meals on metabolism and performance during high-intensity, intermittent exercise. Sixteen male participants completed three 90-min high-intensity intermittent running trials in a single-blinded random order, separated by ~7 d, while fasted (control) and 2 hr after ingesting an isoenergetic low-GI (lentil), or high-GI (potato and egg white) preexercise meal. Serum free fatty acids were higher and insulin lower throughout exercise in the fasted condition (p < .05), but there were no differences in blood glucose during exercise between conditions. Distance covered on a repeated-sprint test at the end of exercise was significantly greater in the low-GI and high-GI conditions than in the control (p < .05). Rating of perceived exertion was lower in the low-GI condition than in the control (p = .01). In a subsample of 5 participants, muscle glycogen availability was greater in the low-and high-GI conditions versus fasted control before the repeated-sprint test (p < .05), with no differences between low and high GI. When exogenous carbohydrates are not provided during exercise both low- and high-GI preexercise meals improve high-intensity, intermittent exercise performance, probably by increasing the availability of muscle glycogen. However, the GI does not influence markers of substrate oxidation during high-intensity, intermittent exercise.

Unlabelled: The glycemic index (GI) of a preexercise meal may affect substrate utilization and performance during continuous exercise., Purpose: To examine the effects of low- and high-GI foods on metabolism and performance during high-intensity, intermittent exercise., Methods: Seven male athletes participated in three experimental trials (low-GI, high-GI, and fasted control) separated by approximately 7 days. Foods were consumed 3 h before (approximately 1.3 g x kg(-1) carbohydrate) and halfway through (approximately 0.2 g x kg(-1) carbohydrate) 90 min of intermittent treadmill running designed to simulate the activity pattern of soccer. Expired gas was collected during exercise to estimate substrate oxidation. Performance was assessed by the distance covered on five 1-min sprints during the last 15 min of exercise., Results: Respiratory exchange ratio was higher and fat oxidation lower during exercise in the high-GI condition compared with fasting (P < .05). The mean difference in total distance covered on the repeated sprint test between low GI and fasting (247 m; 90% confidence limits +/-352 m) represented an 81% (likely, probable) chance that the low-GI condition improved performance over fasting. The mean difference between high GI and fasted control (223 m; +/- 385 m) represented a 76% (likely, probable) chance of improved performance. There were no differences between low and high GI., Conclusions: When compared with fasting, both low- and high-GI foods consumed 3 h before and halfway through prolonged, high-intensity intermittent exercise improved repeated sprint performance. High-GI foods impaired fat oxidation during exercise but the GI did not appear to influence high-intensity, intermittent exercise performance.

High doses of ibuprofen have been shown to inhibit muscle protein synthesis after a bout of resistance exercise. We determined the effect of a moderate dose of ibuprofen (400 mg x d(-1)) consumed on a daily basis after resistance training on muscle hypertrophy and strength. Twelve males and 6 females (approximately 24 years of age) trained their right and left biceps on alternate days (6 sets of 4-10 repetitions), 5 d x week(-1), for 6 weeks. In a counter-balanced, double-blind design, they were randomized to receive 400 mg x d(-1) ibuprofen immediately after training their left or right arm, and a placebo after training the opposite arm the following day. Before- and after-training muscle thickness of both biceps was measured using ultrasound and 1 repetition maximum (1 RM) arm curl strength was determined on both arms. Subjects rated their muscle soreness daily. There were time main effects for muscle thickness and strength (p < 0.01). Ibuprofen consumption had no effect on muscle hypertrophy (muscle thickness of biceps for arm receiving ibuprofen: pre 3.63 +/- 0.14, post 3.92 +/- 0.15 cm; and placebo: pre 3.62 +/- 0.15, post 3.90 +/- 0.15 cm) and strength (1 RM of arm receiving ibuprofen: pre 18.6 +/- 2.8, post 23.4 +/- 3.5 kg; and placebo: pre 18.8 +/- 2.8, post 22.8 +/- 3.4 kg). Muscle soreness was elevated during the first week of training only, but was not different between the ibuprofen and placebo arm. We conclude that a moderate dose of ibuprofen ingested after repeated resistance training sessions does not impair muscle hypertrophy or strength and does not affect ratings of muscle soreness.

Exercise has a beneficial effect on bone, possibly by stimulating estrogen receptor alpha. Because estrogen up-regulates this receptor, estrogen therapy combined with exercise training may be optimal for increasing bone mineral density. Studies combining estrogen therapy and exercise training in postmenopausal women show mixed results, but indicate that the combination of interventions may be more effective for increasing bone mass than either intervention alone. Plant-like estrogens (i.e phytoestrogens such as soy isoflavones) may act as weak estrogen agonists or antagonists, have small beneficial effects on bone, and may interact with exercise for increasing bone mineral density. Phytoestrogen derived from flaxseed (flax lignans) has not been evaluated as extensively as soy isoflavones and thus its effect on bone is difficult to determine. Estrogen or soy isoflavones given to postmenopausal women results in a small increase in lean tissue mass that may be mediated through estrogen receptor alpha on muscle or through decreased inflammation.

Muscle loss with age has a negative effect on strength and functional independence. Age-related loss of muscle is the result of decreased muscle fiber number and size, which are functions of altered hormonal status, physical inactivity, and variations in nutritional intake. Resistance training has a positive effect on muscle mass and strength in the elderly. Studies of protein or creatine supplementation for increasing muscle mass and strength in older individuals are equivocal. The timing of nutritional supplementation may be more important than the absolute daily intake of supplements. Protein or creatine ingestion proximate to resistance-training sessions may be more beneficial for increasing muscle mass and strength than ingestion of protein or creatine at other times of the day, possibly because of increased blood flow and therefore increased transport of amino acids and creatine to skeletal muscle.

Mechanomyography has shown that "resting" muscle is mechanically active, with greater activity after vigorous exercise. This experiment studied the post-exercise resting mechanomyography activity that results from different levels of exercise; the effects of exercise levels on the contralateral non-exercised limb; and the effects of resting muscle length on post-exercise resting mechanomyographic activity. Ten healthy volunteers had mechanomyography recordings over both mid-rectus femoris, at rest, before and after sets (1, 5, 10, 20, and 30 repetitions) of right leg extensions on an isokinetic dynamometer at 60 s(-1). Sets were performed a week apart, after only sedentary activity during the previous two hours. No definite threshold effect was shown. There was a linear correlation between mechanomyography and work done (R = 0.61, P < 0.01). There was a positive correlation of change of activity between the two thighs (R = 0.62, P < 0.01), with the non-exercised thigh demonstrating about half the activity of the exercised thigh. Finally, we observed that mechanomyographic activity was greater when rectus femoris muscle length was shorter (i.e. when the leg was extended versus flexed). We conclude that resting mechanomyography increases with increasing work and that there is a cross-over for increase in mechanomyography in the non-exercised leg, suggesting a neural mechanism. The greater mechanomyographic activity at shorter muscle lengths suggests that muscle that is less stretched could more freely oscillate, producing higher MMG amplitudes. Altered activity of the muscle spindle gamma loop or Golgi tendon apparatus may also play a role in altered activity with different muscle length.

We determined the effects of protein supplementation immediately before (PRO-B) and after (PRO-A) resistance training (RT; 12 weeks) in older men (59-76 years), and whether this reduces deficits in muscle mass and strength compared to younger men (18-40 years). Older men were randomized to PRO-B (0.3 g/kg protein before RT + placebo after RT, n=9), PRO-A (placebo before + protein after RT, n=10), or PLA (placebo before and after RT, n=10). Lean tissue mass, muscle thickness of the elbow, knee, and ankle flexors and extensors, and leg and bench press strength were measured before and after RT and compared to databases of younger subjects (n=22-60). Myofibrillar protein degradation (3-methylhistidine) and bone resorption (cross-linked N-telopeptides) were also measured before and after RT. Lean tissue mass, muscle thickness (except ankle dorsi flexors), and strength increased with training (P<0.05), with little difference between groups. There were no changes in 3-methylhistidine or cross-linked N-telopeptides. Before RT, all measures were lower in the older compared to younger groups (P<0.05), except for elbow extensor muscle thickness. Following training, muscle thickness of the elbow flexors and ankle dorsi flexors and leg press strength were no longer different than the young, and elbow extensor muscle thickness was greater in the old men (P<0.05). Supplementation with protein before or after training has no effect on muscle mass and strength in older men. RT was sufficient to overcome deficits in muscle size of the elbow flexors and ankle dorsi flexors and leg press strength in older compared to younger men.

Some have observed maximal strength of simultaneous bilateral homologous limb contraction is less than the sum of strengths of right and left limbs contracting alone; a phenomenon referred to as the bilateral deficit (BLD). There is controversy on whether there is a BLD for all exercises. We assessed whether a BLD occurs across different exercises (leg press, knee extension, and lat pull-down), whether the BLD could be altered with unilateral or bilateral training, and whether unilateral versus bilateral training was more beneficial for increasing lean tissue mass (LTM). Post-menopausal women (approximately 57 years) were randomized to bilateral (n=14) and unilateral (n=12) training, or non-training control (n=24) groups. Bilateral training involved seven exercises performed with bilateral contractions (two sets, 3 days week-1, 26 weeks). Unilateral training involved the same exercises performed with one limb at a time. A BLD was found for leg press and lat pull-down, but not for knee extension. Bilateral training decreased the BLD; whereas unilateral training had minimal effect on the BLD. The unilateral-training group had a greater increase in lower-body LTM compared to the control group (P<0.05); however, there were no differences between unilateral and bilateral training groups. Both training groups had greater increases in LTM of the upper- and whole-body compared to the control group. We conclude that the BLD is apparent for some exercises (i.e., the leg press and lat pull-down) but not others (i.e., knee extension). Bilateral training reduces the BLD; whereas unilateral training has minimal effect on the BLD.

A number of mechanisms have been proposed for the elevation in oxygen consumption following exercise. Biochemical processes that return muscle to its preexercise state do not account for all the oxygen consumed after exercise. It is possible that mechanical activity in resting muscle, which produces low frequency vibrations (i.e., muscle sounds: mechano-myographic [MMG] activity), could contribute to the excess postexercise oxygen consumption. Therefore the purpose of this study was to determine whether the resting MMG amplitude changes after exercise, and whether the change is related to the elevation in oxygen consumption (VO2). Ten young male subjects (22.9 yrs) performed 30 minutes of exercise on a cycle ergometer at an intensity corresponding to 70% peak VO2. Oxygen consumption was measured by indirect calorimetry, and MMG by an accelerometer placed over the mid-quadriceps before exercise and for 5.5 hours after exercise. MMG activity, expressed as mean absolute acceleration, was significantly elevated for the 5.5 hours of measurement after exercise (p < 0.05). MMG and VO2 decayed exponentially after exercise with time constants of 7.2 minutes and 7.4 minutes, respectively. We conclude that muscle is mechanically active following exercise and that this may contribute to an elevated VO2.

Unlabelled: Muscles exercised before creatine (Cr) supplementation have a greater elevation of intramuscular Cr than nonexercised muscles., Purpose: To determine whether preferential increase of muscle thickness could be achieved by ingesting Cr immediately after exercise of specific muscles over 6 wk. Another purpose was to determine if the increase in lean tissue mass (LTM) with Cr supplementation is greater in males than females., Methods: Subjects randomly assigned to Cr (six males, five females, 0.2 g Cr x kg(-1)) and placebo (PL; five males, five females) performed single-limb training with one side of the body two times per week and with the opposite limbs two times per week. Cr was consumed after training of one side of the body and PL after training the opposite side. Subjects on PL always consumed PL after exercise. Elbow flexors and knee extensors muscle thickness, LTM, fat, and bone mass, and single-limb bench and leg press one-repetition maximum (1-RM) were assessed before and after 6 wk., Results: Within the Cr group, elbow flexors muscle thickness increased more in the limbs trained on days Cr was supplemented compared with limbs trained on days PL was supplemented (P < 0.02). All other measures changed to a similar extent between limbs. Males on Cr had the greatest increase in LTM (P < 0.05) with no difference between females on Cr and PL. Bench press 1-RM increased more in Cr than PL groups (P < 0.01). All other measures changed to a similar extent between groups. Males increased bone mass (P < 0.01) with no effect of Cr supplementation., Conclusion: Supplementing with Cr after training of the arms resulted in greater increase in muscle thickness of the arms. Males have a greater increase in LTM with Cr supplementation than females.

Research in animal models indicates that without estrogen, the effectiveness of exercise for increasing bone mineral in females is reduced. With decreased estrogen levels, there is an increase in the threshold at which strains are detected by bone, in turn reducing the transmission of mechanical to biochemical signals for bone formation. Studies combining estrogen replacement and exercise training in postmenopausal women have yielded mixed results but indicate that the combination of interventions may be more effective than either intervention alone for increasing bone mass. Given the continued debate over the risks and benefits of estrogen replacement, other compounds such as bisphosphonates or phytoestrogens may be preferred in combination with exercise training for optimally increasing bone mass and preventing osteoporotic fracture. Studies on animals show that the combination of bisphosphonate or phytoestrogen supplementation with exercise training is effective, but trials in humans are lacking.

The purpose of this study was to examine the effect of isokinetic eccentric (ECC) and concentric (CON) training at two velocities [fast, 180 degrees s(-1 )(3.14 rad s(-1)) and slow,30 degrees s(-1)(0.52 rad s(-1))] on muscle hypertrophy. Twenty-four untrained volunteers (age 18-36 years) participated in fast- ( n=13) or slow- ( n=11) velocity training, where they trained one arm eccentrically for 8 weeks followed by CON training of the opposite arm for 8 weeks. Ten subjects served as controls (CNT). Subjects were tested before and after training for elbow flexor muscle thickness by sonography and isokinetic strength (Biodex). Overall, ECC training resulted in greater hypertrophy than CON training (P<0.01). No significant strength or hypertrophy changes occurred in the CNT group. ECC (180 degrees s(-1)) training resulted in greater hypertrophy than CON (180 degrees s(-1)) training and CON (30 degrees s(-1)) training (P<0.01). ECC (30 degrees s(-1)) training resulted in greater hypertrophy than CON (180 degrees s(-1)) training (P<0.05), but not CON (30 degrees s(-1)) training. ECC (180 degrees s(-1)) training resulted in the greatest increases in strength (P<0.01). We conclude that ECC fast training is the most effective for muscle hypertrophy and strength gain.

The purpose of this study was to determine whether cross-education, defined as the increase in strength of an untrained limb after training of the contralateral homologous limb, is specific to low and high velocity eccentric training. Twenty-six subjects were randomized into two groups ( n=13 each) that performed unilateral eccentric training of the elbow flexors on an isokinetic dynamometer at velocities of either 30 degrees s(-1) (0.52 rad s(-1)) or 180 degrees s(-1) (3.14 rad s(-1 )). Subjects trained three times per week for 8 weeks. Ten subjects served as controls and did not train. Subjects were tested before and after training for peak torque of the elbow flexors during eccentric and concentric contractions at 30 degrees s(-1) and 180 degrees s(-1). Eccentric peak torque at the velocity of 180 degrees s(-1) in the untrained arm increased only for the group that trained at that velocity (P<0.05). There were no other changes in untrained arms for any of the groups at velocities of 30 degrees s(-1) or 180 degrees s(-1). For the trained arm, the increase in eccentric torque (pooled over velocities) was greatest for the group training at 180 degrees s(-1), whereas the increase in concentric torque was similar for the groups training at 30 degrees s(-1) and 180 degrees s(-1). For the trained arm, there was no specificity for velocity or contraction type. We conclude that cross-education was specific to contraction type and velocity when fast (but not slow) eccentric contractions were used during training; whereas there was no specificity of training in the trained arm.

Purpose: Our purpose was to examine the effects of 2 yr of creatine monohydrate supplementation and exercise on bone health in postmenopausal women. Methods: Two hundred and thirty-seven postmenopausal women (mean age, 59 yr) were randomized to receive creatine (0.14 g·kg-1·d-1) or placebo during a resistance training (3 d·wk-1) and walking (6 d·wk-1) program for 2 yr. Our primary outcome was the femoral neck bone mineral density (BMD), with lumbar spine BMD and proximal femur geometric properties as the secondary outcomes. Results: Compared with placebo, creatine supplementation had no effect onBMD of the femoral neck (creatine: 0.725 ± 0.110 to 0.712 ± 0.100 g·cm-2; placebo: 0.721 ± 0.102 to 0.706 ± 0.097 g·cm-2), total hip (creatine: 0.879 ± 0.118 to 0.872 ± 0.114 g·cm-2; placebo: 0.881 ± 0.111 to 0.873 ± 0.109 g·cm-2), or lumbar spine (creatine: 0.932 ± 0.133 to 0.925 ± 0.131 g·cm-2; placebo: 0.923 ± 0.145 to 0.915 ± 0.143 g·cm-2). Creatine significantly maintained section modulus (1.35 ± 0.29 to 1.34 ± 0.26 vs 1.34 ± 0.25 to 1.28 ± 0.23 cm³ (placebo), P = 0.0011), predictive of bone bending strength, and buckling ratio (10.8 ± 2.6 to 11.1 ± 2.2 vs 11.0 ± 2.6 to 11.6 ± 2.7 (placebo), P = 0.011), predictive of reduced cortical bending under compressive loads, at the narrow part of the femoral neck. Creatine reduced walking time over 80m(48.6 ± 5.6 to 47.1 ± 5.4 vs 48.3 ± 4.5 to 48.2 ± 4.9 s (placebo), P = 0.0008) but had no effect on muscular strength (i.e., one-repetition maximum) during bench press (32.1 ± 12.7 to 42.6 ± 14.1 vs 30.6 ± 10.9 to 41.4 ± 14 kg (placebo)) and hack squat (57.6 ± 21.6 to 84.4 ± 28.1 vs 56.6 ± 24.0 to 82.7 ± 25.0 kg (placebo)). In the subanalysis of valid completers, creatine increased lean tissue mass compared with placebo (40.8 ± 5.7 to 43.1 ± 5.9 vs 40.4 ± 5.3 to 42.0 ± 5.2 kg (placebo), P = 0.046). Conclusions: Two years of creatine supplementation and exercise in postmenopausal women had no effect on BMD; yet, it improved some bone geometric properties at the proximal femur. [ABSTRACT FROM AUTHOR]

Ice hockey players are susceptible to COVID-19 because of close contact and poor arena ventilation. Preventive strategies include reducing arena crowding, practice strategies that reduce clustering of players, at-home rapid tests, symptom screening, and face mask or vaccine recommendations for spectators, coaches, and players. Face masks have little effect on physiological responses or performance and reduce COVID-19 transmission, but shifts should be shortened later in periods to reduce perceived exertion and players should be encouraged to assume a classic "hockey stance" when puck handling to improve peripheral vision. These strategies are important to prevent cancelation of practices or games, which have important physical and psychological benefits. [ABSTRACT FROM AUTHOR]

Background: The number of Masters-level athletes (≥ 35 years of age) taking part in cycling has increased in the past years which may have beneficial effects on their health. The restrictions brought on by the COVID-19 pandemic has the potential to negatively impact the diet, training and fitness of these individuals due to restrictions in place to slow the spread of the virus. Aim: To investigate how the COVID-19 pandemic impacted the diet, training and fitness of Masters-level cyclists. Methods: 32 Masters cyclists (12 males, 20 females; mean age 47 ± 10 years) completed two incremental exercise tests one month apart during the pandemic to assess sport-specific fitness. Participants also completed online questionnaires to report their sedentary behavior and dietary intake before and during the pandemic, and their training volume and intensity for a specified week in February (before the pandemic) and each of March, April and May (during the pandemic). Results: No differences were seen in fitness (p = 0.6), training volume (p = 0.24) or intensity (p = 0.79) and sedentary behavior (p = 0.14) during the pandemic. Energy intake was unchanged (p = 1.0) during the pandemic, but participants consumed lower amounts of key nutrients such as fiber, vitamin A, omega-3 fatty acids and potassium (p < 0.05) while consuming more alcohol (p = 0.008) and vitamin C (p = 0.03). Conclusions: Our data shows that the COVID-19 pandemic has undesirable effects on nutrient and alcohol intake of Masters cyclists without impacting their training regimes, which may have adverse effects on their overall health and fitness in the long term. [ABSTRACT FROM AUTHOR]

Background: Exercise is commonly recommended to prevent and manage osteoporosis. High magnitude strains at rapid rate and short bouts should theoretically elicit an osteogenic response; however, the effects of different levels of impact exercises on several outcomes in people at risk of fracture are still unknown. Objective: To report the effect of impact exercise on falls, fractures, adverse events, mortality, bone mineral density (BMD), physical functioning, and health-related quality of life (QoL). Methods: We included randomized controlled trials testing the effect of impact exercise compared with a non-exercise control on outcomes in adults ≥ 50 years with low BMD or fragility fractures. Two reviewers selected studies and extracted data. Where possible, we pooled outcomes using mean difference (MD) with a fixed-effects model and 95% confidence interval (CI). We reported risk of bias using Cochrane and certainty of evidence using GRADE. Results: We included 29 trials; 19 studies evaluated impact exercise alone, and the remaining trials combined impact with resistance or balance training. Impact exercise alone or combined with resistance training improved Timed Up-and-Go values (MD − 0.95 s, 95% CI − 1.09 to − 0.81, low certainty evidence) and lumbar spine (MD 0.04 g/cm2, 95% CI 0.02–0.06, low certainty evidence) and femoral neck BMD (MD 0.04 g/cm2, 95% CI 0.02–0.07, low certainty evidence). Impact exercise did not improve health-related QoL assessed with QUALEFFO-41 (MD 0.06, 95% CI − 2.18 to 2.30, moderate certainty evidence). The effects of impact exercise on falls, fractures, and mortality are uncertain due to insufficient data. Many trials had a high risk of bias for two or more items. Conclusions: There is low certainty evidence that impact exercise may improve physical function and BMD in people at risk of fracture. The effect of impact exercises on falls, fractures, and mortality remains unclear. Our findings should be interpreted with caution due to risk of bias and small sample sizes. Trial Registration: Registered in Prospero (CRD42018115579) on January 30, 2019. [ABSTRACT FROM AUTHOR]

Objective Osteoporosis clinical practice guidelines recommend exercise to prevent fractures, but the efficacy of exercise depends on the exercise types, population studied, or outcomes of interest. The purpose of this systematic review was to assess the effects of progressive resistance training (PRT) on health-related outcomes in people at risk of fracture. Methods Multiple databases were searched in October 2019. Eligible articles were randomized controlled trials of PRT interventions in men and women ≥50 years with low bone mineral density (BMD) or fracture history. Descriptive information and mean difference (MD) and SD were directly extracted for included trials. A total of 53 studies were included. Results The effects of PRT on the total number of falls (incidence rate ratio [IRR] = 1.05; 95% CI = 0.91 − 1.21; 7 studies) and on the risk of falling (risk ratio [RR] = 1.23; 95% CI = 1.00 − 1.51; 5 studies) are uncertain. PRT improved performance on the Timed "Up and Go" test (MD = −0.89 seconds; 95% CI = −1.01 to −0.78; 13 studies) and health-related quality of life (standardized MD = 0.32; 95% CI = 0.22–0.42; 20 studies). PRT may increase femoral neck (MD = 0.02 g/cm2; 95% CI = 0.01–0.03; 521 participants, 5 studies) but not lumbar spine BMD (MD = 0.02 g/cm2; 95% CI = −0.01–0.05; 4 studies), whereas the effects on total hip BMD are uncertain (MD = 0.00 g/cm2; 95% CI = 0.00–0.01; 435 participants, 4 studies). PRT reduced pain (standardized MD = −0.26; 95% CI = −0.37 to −0.16; 17 studies). Sensitivity analyses, including PRT-only studies, confirmed these findings. Conclusion Individuals at risk of fractures should be encouraged to perform PRT, as it may improve femoral neck BMD, health-related quality of life, and physical functioning. PRT also reduced pain; however, whether PRT increases or decreases the risk of falls, the number of people experiencing a fall, or the risk of fall-related injuries is uncertain. Impact Individuals at risk of fractures should be encouraged to perform PRT, as it may have positive effects on femoral neck BMD, health-related quality of life, physical functioning, and pain, and adverse events are rare. Lay Summary Exercise is recommended for people at risk of osteoporotic fractures. Our study showed that progressive resistance training improves physical functioning, quality of life, and reduces pain. The effects of progressive resistance training on the risk of falling are unclear. Adverse events are rare, and often minor (eg, soreness, pain, musculoskeletal injury). Considering the benefits and safety, people at risk of fractures should engage in progressive resistance training interventions. [ABSTRACT FROM AUTHOR]

Using a multicenter, randomized controlled trial, (N = 123, age 23 ± 4 years) we sought to determine whether administration of a novel, topical creatine supplement could improve muscular performance after acute and repeated (7-day) exposure. To study the acute performance enhancing effects of the supplement, subjects completed 5 sets of 15 maximal concentric single-leg knee extensions with and without the application of a low- (low dose [LD]-3.5 ml) or high-dose (high dose [HD]-7 ml) topical creatine cream. After a wash-out period, subjects had one leg randomized to receive either the creatine or placebo cream, with further randomization into an oral creatine or placebo supplement group. Subjects completed 5 sets of 15 maximal concentric single leg knee extensions before and after the supplementation protocol. After acute application, no significant differences in peak power (LD: 252 ± 93 W, HD: 261 ± 100 W, p = 0.21), average power (LD: 172 ± 65 W, HD: 177 ± 69 W, p = 0.78), or fatigue index (LD: 13.4 ± 10.6%, HD: 14 ± 11.9%, p = 0.79) were observed between experimental and placebo creams (peak power: LD: 244 ± 76 W, HD: 267 ± 109 W; average power: LD: 168 ± 57 W, HD: 177 ± 67 W; fatigue index: LD: 12.4 ± 9.6%, HD: 12.8 ± 10.6%) or when controlling for sex. After the 7-day supplementation protocol, a significant increase in average power (creatine: 203 ± 61-220 ± 65 W, placebo: 224 ± 61-214 ± 61 W) and peak power (creatine: 264 ± 73-281 ± 80 W, placebo: 286 ± 79-271 ± 73 W) in the leg receiving creatine cream was observed in male subjects. No differences were observed in female subjects. The topical creatine cream did not enhance measures of muscle performance after acute application, but was able to improve peak and average power in male subjects after 7 consecutive days of application. [ABSTRACT FROM AUTHOR]

Objective: Tart cherry concentrate has been shown to improve muscle function, and reduce muscle damage, oxidative stress/inflammation, and muscle soreness in athletes; however, evidence for acute endurance performance benefits is scarce. The purpose of this review was to evaluate the effect of tart cherry juice on endurance exercise performance with a meta-analysis.Method: Data sources included Medline, Embase, Web of Science, and Google Scholar. Eligibility criteria were randomized controlled trials with endurance exercise performance tests. Participants were healthy individuals. Interventions included tart cherry supplementation and placebo ingested before, and/or on the day of exercise. Ten studies were included (totaling 127 males and 20 females). Standardized mean differences (SMD) with 95% confidence intervals were calculated for each study and pooled effects were assessed.Results: Tart cherry concentrate in juice or powdered form, ingested for 7 days to 1.5 hours before exercise performance testing significantly improved endurance exercise performance (SMD: 0.36; 95% CI: 0.07 to 0.64; p = 0.01; I2 = 0%) upon pooling of the ten studies.Conclusions: Tart cherry concentrate has a significant benefit for endurance exercise performance. Key teaching pointsTart cherry concentrate has a significant benefit for endurance exercise performance.Tart cherry concentrate may enhance endurance exercise performance via its low glycemic index, anti-inflammatory and anti-oxidative capacity, and blood flow enhancing effects. [ABSTRACT FROM AUTHOR]

Free weights offer a more unstable training environment, which enhances muscle recruitment, whereas some machines have the advantage of using a "cam" pulley system that better matches strength curves. We compared the effect of training with free weights vs. machines on muscle mass, strength, free testosterone, and free cortisol concentrations. Forty-six subjects (26 women; 22 6 3 years) were randomized to train using free weights or machines for 8 weeks (with each muscle group trained 2-3/weeks, 3-4 sets of 4-10 repetitions). Muscle thickness and strength were measured at 0 and 8 weeks. Salivary hormone concentrations were assessed before and at the end of workouts at the beginning, midway (4 weeks), and end (8 weeks) of the training intervention. Biceps and quadriceps muscle thickness increased (p< 0.01) with no difference between groups. There was a group 3 time interaction for machine bench press strength (p = 0.05) with the machine group increasing more than the free-weight group (13.9 vs. 8.6%). Free-weight bench press and squat, and Smith machine squat strength increased in both groups (11-19%; p< 0.01) with no difference between groups. Men in the free-weight group had a greater increase in free testosterone from before to after acute training sessions than men in the machine group and all women (p< 0.01); however, there was no differences between groups in free cortisol response to acute resistance exercise. Training sessions with free weights induced greater increases in free testosterone in men; however, training with free weights or machines resulted in similar increases in muscle mass and strength. [ABSTRACT FROM AUTHOR]

Objective: Effects of lifestyle modification on reproductive function in polycystic ovary syndrome (PCOS) remain poorly elucidated. We compared the effects of a pulse‐based diet (lentils, beans, split peas and chickpeas) with Therapeutic Lifestyle Changes (TLC) diet on ultrasonographic markers of ovarian morphology, hyperandrogenism and menstrual irregularity in PCOS. Design: Randomized controlled trial. Patients: Women with PCOS (18‐35 years). Measurements: Thirty women randomized to the pulse‐based and 31 to TLC groups completed a 16‐week intervention without energy restriction. Groups performed aerobic exercise (minimum of 5 days/wk; 45 minutes/d) and received health counselling (monthly) and longitudinal follow‐up. Follicle numbers per ovary (FNPO, 2‐9 mm), ovarian volume (OV), free androgen index (FAI) and menstrual cycle length were measured pre‐ and postintervention. Results: Follicle numbers per ovary (mean change ± SD, −10 ± 15), OV (−2.7 ± 4.8 mL), FAI (−3 ± 2) and menstrual cycle length (−13 ± 47 days) decreased over time in both groups (All: P <.01), without group‐by‐time interactions (All: P ≥.13). Attrition rate was 33.7% and comparable between groups (P =.94). Adherence to diet intervention negatively correlated with changes in FNPO (r=−0.54), OV (r=−0.35) and FAI (r = −.29) in pooled groups (All: P ≤.04). Groups maintained reduced OV, FNPO, FAI and menstrual cycles 6 months postintervention; however, decreased FNPO and FAI at 16 weeks tended to revert to baseline levels 12 months postintervention in both groups (All: P ≤.05). Conclusions: Both interventions improved ovarian dysmorphology, hyperandrogenism and menstrual irregularity in PCOS, and no diet appeared to be superior at improving reproductive outcomes. Our observations highlight the importance of longitudinal surveillance for sustainable adherence to newly adopted healthy lifestyle behaviours and reproductive health in PCOS (ClinicalTrials.gov identifier, NCT01288638). [ABSTRACT FROM AUTHOR]

Objective: A favorable dietary composition to increase health-related quality of life (HRQoL) in PCOS remains unclear. We compared changes in HRQoL of women with PCOS who participated in a low-glycemic-index pulse-based (lentils, beans, split peas, and chickpeas) or the Therapeutic Lifestyle Changes (TLC) diet intervention.Methods: Thirty women in the pulse-based and 31 in the TLC groups (18-35 years) completed a 16-week intervention without energy-restriction. Groups participated in health counseling (monthly) and aerobic exercise (5 days/week; 45 minutes/day).Results: Fifty-five (90.2%) women completed a PCOS-specific HRQoL survey. Greatest mean increases in time-effects occurred in the domains of healthy eating, PCOS knowledge, active living, healthcare satisfaction, feelings and experiences about intervention, and health concerns, respectively (p ≤ 0.02), without group-by-time interactions (p ≥ 0.13). Decreased weight (r = -0.35) and homeostatic model assessment of insulin resistance (r = -0.18) correlated with increased scores of PCOS knowledge; adherence to intervention correlated with increased scores of active living (r = 0.39) and healthy eating (r = 0.53; p ≤ 0.03).Conclusions: Both interventions improved HRQoL scores in women with PCOS without prescribed energy-restriction. Our observations add novel insights into current evidence and elucidate the need for future psychological research to target lifestyle modifications for improving HRQoL and unique psychological complications of PCOS in this high-risk population (CinicalTrials.gov identifier:NCT01288638). [ABSTRACT FROM AUTHOR]

Purpose: The authors examined the combined effects of conjugated linoleic acid (CLA), creatine (C), and whey protein (P) supplementation during strength training. Methods: Sixty-nine participants (52 men, 17 women; M ± SD age 22.5 ± 2.5 yr) were randomly assigned (double-blind) to 1 of 3 groups: CCP (6 g/d CLA + 9 g/d C + 36 g/d P; n = 22), CP (C + P + placebo oil; n = 25), or P (P + placebo oil; n = 22) during 5 wk of strength training (4-5 sets, 6-12 repetitions, 6 d/wk). Measurements were taken for body composition (air-displacement plethysmography), muscle thickness (ultrasound) of the flexors and extensors of the elbow and knee, 1-repetitionmaximum (1-RM) strength (leg press and bench press), urinary markers of bone resorption (N-telopeptides, NTx), myofibrillar protein catabolism (3-methylhistidine; 3-MH), oxidative stress (8-isoprostanes), and kidney function (microalbumin) before and after training. Results: Contrast analyses indicated that the CCP group had a greater increase in bench-press (16.2% ± 11.3% vs. 9.7% ± 17.0%; p < .05) and legpress (13.1% ± 9.9% vs. 7.7% ± 14.2%; p < .05) strength and lean-tissue mass (2.4% ± 2.8% vs. 1.3% ± 4.1%; p < .05) than the other groups combined. All groups increased muscle thickness over time (p < .05). The relative change in 3-MH (CCP -4.7% ± 70.2%, CP -0.4% ± 81.4%, P 20.3% ± 75.2%) was less in the groups receiving creatine (p < .05), with the difference for NTx also close to significance (p = .055; CCP -3.4% ± 66.6%, CP -3.9% ± 64.9%, P 26.0% ± 63.8%). There were no changes in oxidative stress or kidney function. Conclusion: Combining C, CLA, and P was beneficial for increasing strength and lean-tissue mass during heavy resistance training. [ABSTRACT FROM AUTHOR]

Creatine (Cr) supplementation increases muscle mass, strength, and power. Arginine α-ketoglutarate (A-AKG) is a precursor for nitric oxide production and has the potential to improve blood flow and nutrient delivery (i.e., Cr) to muscles. This study compared a commercial dietary supplement of Cr, A-AKG, glutamine, taurine, branched-chain amino acids, and medium-chain triglycerides with Cr alone or placebo on exercise performance and body composition. Thirty-five men (∼23 yr) were randomized to Cr + A-AKG (0.1 g · kg-1 · d-1 Cr + 0.075 g · kg-1 · d-1 A-AKG, n = 12), Cr (0.1 g · kg-1 · d-1, n = 11), or placebo (1 g · kg-1 · d-1 sucrose, n = 12) for 10 d. Body composition, muscle endurance (bench press), and peak and average power (Wingate tests) were measured before and after supplementation. Bench-press repetitions over 3 sets increased with Cr + A-AKG (30.9 ± 6.6 → 34.9 ± 8.7 reps; p < .01) and Cr (27.6 ± 5.9 → 31.0 ± 7.6 reps; p <.01), with no change for placebo (26.8 ± 5.0 → 27.1 ± 6.3 reps). Peak power significantly increased in Cr + A-AKG (741 ± 112 → 794 ± 92 W; p < .01), with no changes in Cr (722 ± 138 → 730 ± 144 W) and placebo (696 ± 63 → 705 ± 77 W). There were no differences in average power between groups over time. Only the Cr-only group increased total body mass (79.9 ± 13.0→81.1 ± 13.8 kg; p < .01), with no significant changes in lean-tissue or fat mass. These results suggest that Cr alone and in combination with A-AKG improves upper body muscle endurance, and Cr + A-AKG supplementation improves peak power output on repeated Wingate tests. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of Red Bull energy drink on Wingate cycle performance and muscle endurance. Healthy young adults (N = 15, 11 men, 4 women, 21 ± 5 y old) participated in a crossover study in which they were randomized to supplement with Red Bull (2 mg/kg body mass of caffeine) or isoenergetic, isovolumetric, noncaffeinated placebo, separated by 7 d. Muscle endurance (bench press) was assessed by the maximum number of repetitions over 3 sets (separated by 1-min rest intervals) at an intensity corresponding to 70% of baseline 1-repetition maximum. Three 30-s Wingate cycling tests (load = 0.075 kp/kg body mass), with 2 min recovery between tests, were used to assess peak and average power output. Red Bull energy drink significantly increased total bench-press repetitions over 3 sets (Red Bull = 34 ± 9 vs. placebo = 32 ± 8, P < 0.05) but had no effect on Wingate peak or average power (Red Bull = 701 ± 124 W vs. placebo = 700 ± 132 W, Red Bull = 479 ± 74 W vs. placebo = 471 ± 74 W, respectively). Red Bull energy drink significantly increased upper body muscle endurance but had no effect on anaerobic peak or average power during repeated Wingate cycling tests in young healthy adults. [ABSTRACT FROM AUTHOR]

The authors previously found that creatine (Cr) combined with 12 weeks of resistance training enhanced muscle strength and endurance and lean tissue mass (LTM) in older men. Their purpose in this study was to assess these variables with cessation of Cr combined with 12 weeks of reduced training (33% lower volume) in a subgroup of these men (n = 8,73 years old) compared with 5 men (69 years old) who did not receive Cr. Strength (1-repetition maximum [1-RM]), endurance (maximum number of repetitions over 3 sets at 70-80% 1-RM), and LTM (dual-energy X-ray absorptiometry) were assessed before and after 12 weeks of Cr cessation combined with reduced-volume training. No changes in strength or LTM occurred. Muscle endurance was significantly reduced (7-21%; p < .05), with the rate of change similar between groups. Withdrawal from Cr had no effect on the rate of strength, endurance, and loss of lean tissue mass with 12 weeks of reduced-volume training. [ABSTRACT FROM AUTHOR]

Presents a study that examined the effect of 21 days of low dose creatine supplementation and resistance training on force output, power output and total work performed until fatigue. Functions of creatine; Beneficial effects of dietary creatine supplementation on exercise performance; Results of statistical analysis.

Low-glycemic index carbohydrates are potentially better for endurance performance as they result in greater fat oxidation and lower carbohydrate oxidation due to lower insulin release. We compared the effects of pre-exercise feeding with a low-glycemic index lentil-based sports nutrition bar, a commercially-available sports nutrition bar with moderate-glycemic index, and a non-caloric placebo on metabolism and performance during endurance cycling (Trial 1). Using a randomized, counterbalanced, crossover design, endurance-trained individuals (n = 11; eight males; 26 ± 6y; VO2peak 51.4 ± 1.6 mL/kg/min) consumed 1.5 g/kg available carbohydrate from a lentil bar and a moderate-glycemic index bar, as well as a placebo, 1h before endurance cycling (75 min at 65% VO2peak, followed by a 7 km time trial). We also compared post-exercise consumption of the low-glycemic index bar with another moderate-glycemic index bar on next-day exercise performance as an assessment of recovery (Trial 2). In Trial 1, fat or carbohydrate oxidation rates were not different between the bar conditions (p > 0.05). Blood lactate was lower during the low- versus the moderate-glycemic index condition after 75 minutes of cycling (2.6 versus 4.0 mmol/L, p < 0.05) and at the end of the time trial (7.4 versus 9.1 mmol/L, p < 0.05). Time trial performance improved (p < 0.05) after consumption of the low- (574 ± 55 s) and moderate-glycemic index (583 ± 59 s) bars compared to the placebo (619 ± 81 s). In Trial 2 (next-day recovery), performance improved (p < 0.05) with the low-glycemic index bar (547 ± 42 s) compared to the moderate-glycemic index bar (569 ± 42 s) and the placebo (566 ± 34 s). Low- and moderate-glycemic index sports nutrition bars improved cycling exercise performance; however, only the low-glycemic index bar improved next day performance. [ABSTRACT FROM AUTHOR]

Purpose: Our purpose was to compare supramaximal versus submaximal intensity eccentric training performed until volitional fatigue.Methods: Thirty-two young adults (19 males) were randomized into one of three groups: (1) ECC110 performed eccentric (ECC) only contractions at 110% of concentric (CON) 1-repetition maximum (1RM); (2) ECC80 performed ECC only contractions at 80% of CON 1RM; (3) a control group. Training progressed from 3 to 6 sets of unilateral ECC training of the elbow flexors over 8 weeks, with each set performed until volitional fatigue. Elbow flexors muscle thickness (via ultrasound) and 1RM were assessed pre- and post-training. Rating of perceived exertion (RPE) and muscle soreness was self-reported.Results: Both ECC110 (+0.25 cm) and ECC80 (+0.21 cm) showed a greater post-training increase in muscle thickness compared to control (-0.01 cm) (p < 0.05), with no differences between ECC110 and ECC80. ECC80 (+1.23 kg) showed a greater post-training increase in strength compared to control (p < 0.05), while ECC110 (+0.76 kg) had no significant difference post-training vs. control (-0.01 kg). ECC80 had significantly lower average RPE scores than ECC110 (p < 0.05).Conclusions: Both supramaximal intensity eccentric training and submaximal intensity eccentric training are effective for increasing muscle size, but submaximal eccentric training is perceived to require less exertion than supramaximal training. These findings suggest that submaximal eccentric training may be an ideal strategy to increase muscle size and strength in individuals whose needs warrant training at a lower level of exertion. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Resistance training with ibuprofen supplementation may improve musculoskeletal health in postmenopausal women. The study purpose was to determine the efficacy of resistance training and ibuprofen supplementation on bone and muscle properties in postmenopausal women. Methods: Participants (n = 90, 65.3 ± 4.9 yr) were randomly assigned to: supervised resistance training or stretching (placebo-exercise) with postexercise ibuprofen (400 mg) or placebo supplementation for 3 d⋅wk-1 (9 months). Baseline and postintervention measurements included distal and shaft scans of the forearm and lower leg using peripheral quantitative computed tomography. Distal site outcomes included cross-sectional area, content, and density for total and trabecular bone, as well as estimated bone strength in compression. Shaft site outcomes included total bone area; cortical bone area, content, and density; estimated bone strength in torsion; and muscle area and density. Results: Exercise-supplement-time interactions for total bone content at the distal radius (P = 0.009) and cortical density at the radius shaft (P = 0.038) were significant. Resistance training with ibuprofen decreased total bone content (-1.5%) at the distal radius in comparison to the resistance training (0.6%; P = 0.032) and ibuprofen alone (0.5%; P = 0.050). Change in cortical density at the radius shaft differed between the stretching with placebo and ibuprofen supplementation groups (-1.8% vs 1.1%; P = 0.050). Resistance training preserved muscle density in the lower leg more so than stretching (-3.1% vs -5.4%; P = 0.015). Conclusions: Ibuprofen consumed immediately after resistance training had a deleterious effect on bone mineral content at the distal radius, whereas resistance training or ibuprofen supplementation individually prevented bone loss. Resistance training prevented muscle density decline in the lower leg. [ABSTRACT FROM AUTHOR]

Peak aerobic power (V̇o2peak) is decreased after blood donation, but the time course for full recovery is unknown. We measured V̇o2peak and exercise time to fatigue before and weekly for 4 weeks after 450-ml blood donation at a blood donor clinic, to determine the time course of recovery. Twelve moderately active individuals (2 women, 10 men; 24.3 ± 5.2 years) of average aerobic fitness (based on their V̇o2peak relative to normative values) completed V̇o2peak exercise tests before donation, the day after donation, and at weekly intervals for 4 weeks after donation. V̇o2peak was determined by an incremental exercise test on a cycle ergometer. At baseline, mean absolute and relative V̇o2peak values were 4.06 ± 0.92 L·min−1 and 46.6 ± 7.0 ml·kg−1·min−1, respectively. V̇o2peak was significantly decreased on day 1 (3.85 ± 0.89 L·min−1; 44.0 ± 6.5 ml·kg−1·min−1) and during week 2 (3.91 ± 0.97 L·min−1; 44.5 ± 7.2 ml·kg−1·min−1) after blood donation (p < 0.05), and recovered at week 3 after donation. Time to fatigue and peak heart rate were not significantly affected by blood donation. We conclude that blood donation causes a significant decrease in V̇o2peak for between 2 and 3 weeks. The practical application of this study is that aerobic power in people of average fitness will be decreased, up to 3 weeks after donating blood. Despite this, there is no effect of blood donation on performance as measured by time to fatigue during an incremental test on a cycle ergometer. [ABSTRACT FROM AUTHOR]