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1.
Int J Sports Physiol Perform ; 18(9): 1047-1052, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37527821

ABSTRACT

PURPOSE: Mental rehearsal is commonly employed, with positive visualization proposed to enhance complex skill performance. Additionally, video stimulus has been associated with enhanced kinesthetic sensations and rapid hormone fluctuations that may contribute to enhancing mental rehearsal and the conscious and unconscious emotional state for skill execution. Here, we assessed the impact of a 15-minute mental rehearsal intervention on rugby-specific tasks and the associated hormone profile. METHODS: Professional rugby players (N = 10) volunteered for a randomized crossover study. They completed three 15-minute preparatory phases (positive or negative video-guided mental rehearsal or self-directed mental rehearsal alone) prior to an exercise stressor and rugby-specific passing task. Salivary testosterone and cortisol were monitored to assess stress responses. RESULTS: Performance during the rugby passing task was improved following the positive video condition (91% [7.4%]) compared to the negative video (79% [6.0%]; ES: 1.22 ± 0.75) and self-visualization (86% [5.8%]; ES: 0.58 ± 0.75), with a significant correlation observed between passing performance and salivary testosterone (r = .47 ± .34, P = .0087). Positive video imagery prior to an exercise stressor also significantly enhanced physiological stress resilience (r = .39 ± .36, P = .0352). CONCLUSIONS: This pilot study demonstrates that mental rehearsal was enhanced by appropriate, context-specific video presentation. We propose that the interaction between sex steroids, the adrenal axis, and subsequent conscious and unconscious behaviors may be relevant to competitive rugby. Specifically, we suggest that relatively elevated free testosterone imparts a degree of stress resilience, which may lead to enhanced expression of competitive behaviors and provide an enhanced state for rugby skill execution.


Subject(s)
Athletic Performance , Football , Humans , Cross-Over Studies , Pilot Projects , Rugby , Athletic Performance/physiology , Football/physiology , Saliva/metabolism , Testosterone/metabolism
2.
J Therm Biol ; 100: 103048, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34503795

ABSTRACT

This manuscript aims to evaluate the influence of a novel passive heat acclimation program among human participants in the physical performance, as well as in several physiological parameters. 36 male football players were acclimated using a dry sauna bath to extreme hot (100 ± 3 °C), performing a total of nine sauna sessions with a weekly frequency of three sessions. The players were randomly into the sauna group (SG; n = 18; age: 20.69 ± 2.09 years) and the control group (CG; n = 18; age: 20.23 ± 1.98 years). All participants performed maximal effort test until exhaustion as well as hamstring flexibility test before and after the acclimation program. Anthropometric, respiratory, circulatory, hematological and physiological variables were evaluated at the beginning and at the end of the survey. Statistical analysis consisted of a Mann-Whitney U test to determine differences between groups at the beginning and at the end of the survey and a Wilcoxon test for paired samples to compare the differences for each group separately. Additionally, size effects of the pre-post acclimation changes were calculated. After the acclimation program SG participants experienced a diminution in body weight (p < 0.01), body mass index (p < 0.01), body fat (p < 0.05) and fat percentage (p < 0.05) decreased. Hamstring flexibility (p < 0.05) and work capacity (p < 0.05) increased. External basal temperature decreased (p < 0.05) as well as post-exercise systolic and diastolic blood pressures (p < 0.05). Finally, maximal oxygen uptake (ml Kg-1 min-1) (p < 0.05), maximal minute ventilation (p < 0.05) and maximal breath frequency (p < 0.05) increased at the end of the intervention. There were no significant changes in the CG in any variable. Favorable adaptations have been observed in this survey, suggesting a beneficial effect of extreme heat acclimation on physical performance. Several of the observed responses seem interesting for sport performance and health promotion as well. However, this is a novel, extreme protocol which requires further research.


Subject(s)
Acclimatization , Athletic Performance , Football/physiology , Steam Bath/methods , Adolescent , Body Temperature , Humans , Male , Oxygen Consumption , Physical Conditioning, Human/methods , Young Adult
3.
Curr Sports Med Rep ; 20(7): 359-365, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-34234091

ABSTRACT

ABSTRACT: This article discusses the "bidirectional" relationship between inflammatory bowel disease (IBD) and physical activity. Intestinal symptoms and extraintestinal manifestations of IBD negatively impact a patient's ability to participate in sports. IBD also impacts athletic performance via its effects on muscle mass, muscle function, bone density, and fatigue. Surveys of IBD patients consistently show that IBD interferes with athletic participation. While IBD negatively affects physical activity, there is growing evidence that physical activity can be beneficial for IBD patients. Prospective studies have revealed that structured physical activities may positively influence inflammatory markers, disease activity, muscle strength, bone density, fatigue, stress, anxiety, and quality of life. This suggests that physical activity may be a simple and safe adjuvant therapy for IBD patients. Future studies assessing the optimal activity regimen are warranted. Finally, a cohort of professional athletes with IBD are described for the first time - football players in the National Football League.


Subject(s)
Athletes , Athletic Performance/physiology , Exercise/physiology , Inflammatory Bowel Diseases/physiopathology , Sports/physiology , Anxiety/therapy , Bone Density/physiology , Erythema Nodosum/etiology , Fatigue/physiopathology , Football/physiology , Football/statistics & numerical data , Humans , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/epidemiology , Inflammatory Bowel Diseases/prevention & control , Joint Diseases/classification , Joint Diseases/etiology , Muscle, Skeletal/physiology , Physical Functional Performance , Pyoderma Gangrenosum/etiology , Quality of Life , Scleritis/etiology , Skin Diseases/etiology , Stress, Physiological/physiology , Uveitis/etiology
4.
J Sci Med Sport ; 24(2): 195-199, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32847731

ABSTRACT

Probiotic supplementation may offer team sport athletes a range of benefits beyond the immune and gastrointestinal systems. OBJECTIVES: To examine the effects of a probiotic formulation on perceptual markers of sleep quality and quantity, and muscle soreness, leg heaviness and motivation in elite rugby union athletes. METHODS: A double-blind randomised controlled trial involving 19 elite male rugby athletes was conducted over 17 weeks encompassing both domestic and international competition. Psychometric variables and salivary biomarkers were assessed twice a week. Athletes were assigned either a daily probiotic (Ultrabiotic 60™) and Saccharomyces boulardii (during international competition) or a placebo. Associations between psychometric scores for perceptual and salivary biomarkers of sleep (melatonin) and inflammation C-reactive protein (CRP) were investigated. RESULTS: Muscle soreness was ∼0.5 units lower (F(1, 343)=42.646, p<0.0001) and leg heaviness scores ∼0.7 units lower (F(1, 334)=28.990, p<0.0001) in the probiotic group compared to the placebo group. Across both groups, as self-reported muscle soreness scores and salivary CRP concentrations increased, sleep quantity, quality and motivation scores decreased. Conversely as muscle soreness scores and CRP decreased, sleep quantity and quality, and motivation scores improved. CONCLUSIONS: A long-term programme of probiotic supplementation in international-level rugby union players may yield favourable effects on self-reported muscle soreness and sleep quality associated with muscle soreness during training and competitions.


Subject(s)
Athletic Performance/physiology , Football/physiology , Myalgia/prevention & control , Probiotics/administration & dosage , Sleep/physiology , Adult , Athletic Performance/psychology , Biomarkers/metabolism , C-Reactive Protein/metabolism , Competitive Behavior/physiology , Double-Blind Method , Football/injuries , Football/psychology , Humans , Leg/physiology , Male , Melatonin/metabolism , Motivation , Psychometrics , Saliva/metabolism , Self Report , Young Adult
5.
Sports Biomech ; 20(3): 304-318, 2021 Apr.
Article in English | MEDLINE | ID: mdl-30526367

ABSTRACT

The main aim of this study was to explore the variability in the load-velocity relationship through the use of multilevel mixed regression models. The relationship between relative load (% of one repetition maximum: %1RM) and velocity was obtained in a sample of high-level judokas and rugby players (8 women and 13 men) for the bench press (BP) and parallel squat (SQ). The load-velocity relationship for the squat was obtained for the external load (barbell load) and for the system mass (barbell plus body mass). The data were fitted by different multilevel mixed regression models. Including the sex factor in the models improved the goodness of fit for the BP but not for the squat exercises. All the models detected significant inter-individual variability in both intercepts and slopes (p < 0.05 in all the cases). A decrease of 0.15, 0.10 and 0.16 m/s of velocity for each 10% of increment in the relative load were estimated for BP and squat considering the external load and the system mass, respectively. The multilevel mixed regression models detected significant inter-individual variability in the slope and intercept of the load-velocity relationship what entails differences in the velocity associated with a fixed percentage (%) of the one-repetition maximum load.


Subject(s)
Biomechanical Phenomena/physiology , Football/physiology , Martial Arts/physiology , Resistance Training , Cross-Sectional Studies , Female , Humans , Male , Random Allocation , Regression Analysis , Reproducibility of Results , Sex Factors , Warm-Up Exercise , Young Adult
6.
Int J Sport Nutr Exerc Metab ; 31(1): 73-89, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33321472

ABSTRACT

Professional rugby league (RL) football is a contact sport involving repeated collisions and high-intensity efforts; both training and competition involve high energy expenditure. The present review summarizes and critiques the available literature relating the physiological demands of RL to nutritional requirements and considers potential ergogenic supplements that could improve players' physical capacity, health, and recovery during the preparatory and competition phases of a season. Although there may not be enough data to provide RL-specific recommendations, the available data suggest that players may require approximately 6-8 g·kg-1·day-1 carbohydrate, 1.6-2.6 g·kg-1·day-1 protein, and 0.7-2.2 g·kg-1·day-1 fat, provided that the latter also falls within 20-35% of total energy intake. Competition nutrition should maximize glycogen availability by consuming 1-4 g/kg carbohydrate (∼80-320 g) plus 0.25 g/kg (∼20-30 g) protein, 1-4 hr preexercise for 80-120 kg players. Carbohydrate intakes of approximately 80-180 g (1.0-1.5 g/kg) plus 20-67 g protein (0.25-0.55 g/kg) 0-2 hr postexercise will optimize glycogen resynthesis and muscle protein synthesis. Supplements that potentially improve performance, recovery, and adaptation include low to moderate dosages of caffeine (3-6 mg/kg) and ∼300 mg polyphenols consumed ∼1 hr preexercise, creatine monohydrate "loading" (0.3 g·kg-1·day-1) and/or maintenance (3-5 g/day), and beta-alanine (65-80 mg·kg-1·day-1). Future research should quantify energy expenditures in young, professional male RL players before constructing recommendations.


Subject(s)
Athletic Performance/physiology , Competitive Behavior/physiology , Football/physiology , Nutritional Requirements , Adaptation, Physiological , Adolescent , Dietary Supplements , Energy Metabolism , Humans , Male , Nutritional Status , Performance-Enhancing Substances , Young Adult
7.
J Sports Sci ; 37(22): 2596-2603, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31354059

ABSTRACT

This study aimed to compare the goodness of fit and the reliability of different regression models for fitting the force-velocity relationship (FV) of bench press (BP) and squat (SQ). Additionally, the reliability of the position on FV of the velocity (V1RM) and the force performed with the 1RM (F1RM) was explored. Nine rugby players and 12 judokas participated in this study. The FV of BP and SQ were obtained twice by a protocol performed until the 1RM. Individual FV were fitted by linear (LM), quadratic polynomial (PM), and exponential models (EM). Adjusted coefficients of determination of LM and PM (medians higher than 0.919) were higher than for EM. The reliability was higher for LM in comparison with PM. The reliability of V1RM was not acceptable (CV% = 19 and 18% for BP and SQ). High reliability was observed for F1RM (CV% = 3 and 2% for BP and SQ) and for the ratio between F1RM and the force-axis intercept of FV (CV% = 2 and 4% for BP and SQ). The reliability of the relative values of F1RM around 92 and 87% of F0 for BP and SQ suggests the use of these values for monitoring resistance training programmes.


Subject(s)
Linear Models , Models, Statistical , Resistance Training/methods , Resistance Training/statistics & numerical data , Weight Lifting/physiology , Weight Lifting/statistics & numerical data , Adult , Biomechanical Phenomena , Cross-Sectional Studies , Female , Football/physiology , Humans , Male , Martial Arts/physiology , Reproducibility of Results , Young Adult
8.
Am J Phys Med Rehabil ; 98(11): 964-970, 2019 11.
Article in English | MEDLINE | ID: mdl-31135462

ABSTRACT

OBJECTIVE: The aims of the study were to assess the feasibility of performing acupuncture on multiple adolescent athletes in a warm weather, high-intensity training environment and to measure perceived effects of acupuncture on delayed-onset muscle soreness and sense of well-being. DESIGN: This is a prospective feasibility study (registered clinical trial NCT03478800). Forty-two healthy male participants, aged 13-18 yrs, were involved in at least 1 of 5 treatment days for a total of 147 individual treatment sessions. Fifteen-minute treatments of traditional needle acupuncture were administered at the football field. Time, cost, adverse effects, and participant/provider ratio were observed. Effect on delayed-onset muscle soreness and sense of well-being were measured via pretreatment and posttreatment visual analog scale (0-10) rating analyses. RESULTS: The results are as follows: time required by research staff on treatment days, 75 mins; total cost, US $700; temperature range, 21°C-28°C; and largest participant to acupuncturist ratio, 7-10:1. No major adverse effects occurred; 55% reported minimal adverse effects, such as mild focal numbness or tingling. Overall pretreatment to posttreatment effect on delayed-onset muscle soreness (average over 5 days) demonstrated significantly improved posttreatment scores (pre 4.6 ± 2.0; post 2.9 ± 2.2, P < 0.001). There was no significant effect on sense of well-being (P = 0.12). CONCLUSIONS: Effectively providing acupuncture to multiple adolescent football players in their training environment is feasible with appropriate staff and resources. Despite mild adverse effects, treatment was well tolerated. This study provides guidance on acupuncture delivery to other athletes in their training environments.


Subject(s)
Acupuncture Therapy/methods , Acupuncture Therapy/psychology , Athletes/psychology , Football/physiology , Myalgia/rehabilitation , Adolescent , Feasibility Studies , Healthy Volunteers , High-Intensity Interval Training/adverse effects , Humans , Male , Myalgia/etiology , Myalgia/psychology , Pain Perception , Prospective Studies , Treatment Outcome
9.
J Sports Sci Med ; 18(1): 160-171, 2019 03.
Article in English | MEDLINE | ID: mdl-30787664

ABSTRACT

Both foam rolling and joint distraction training with elastic bands are very popular interventions designed to improve muscular function, motor performance, and joint range of motion, as well as to reduce feeling of fatigue and delayed onset of muscle soreness. The heterogeneity of methods used among studies however prevents from drawing firm conclusions about the optimal content of pre/post interventions. The present study aims at answering the following questions: i) Do foam rolling and joint distraction with elastic band training improve joint range of motion in national rugby players? ii) Do short and long rolling durations have similar effects on range of motion? In a first experiment, we compared ankle, knee, and hip flexibility scores in 30 national rugby players after a 7-week foam rolling training program involving either a short (20s) or long (40s) rolling duration. Data revealed that foam rolling substantially improved all range of motion scores, regardless the rolling duration (performance gains ranged from 9 to 18° in the foam rolling groups, i.e. 8 to 20% increase, but remained under 2° in the control group). In a second experiment, we investigated the effect of a 5-week joint distraction with elastic band training program on hamstring and adductor range of motion in 23 national rugby players. Data showed that elastic band training significantly improved sit-and-reach (29.16% increase, p = 0.01) as well as side split (2.31% increase, p < 0.001) stretching performances. Taken together, present findings confirm that both foam rolling and joint distraction exercises with elastic bands are likely to enhance joint range of motion and specific mobility patterns during sport performance, and further serve prophylaxis. Such effects therefore constitute a promising avenue for clinical, home therapy, and personal flexibility training.


Subject(s)
Football/physiology , Lower Extremity/physiology , Massage/methods , Range of Motion, Articular/physiology , Resistance Training/methods , Adolescent , Ankle/physiology , Hip/physiology , Humans , Knee/physiology , Male , Massage/instrumentation , Resistance Training/instrumentation , Sports Equipment , Young Adult
10.
J Athl Train ; 54(1): 7-11, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30645147

ABSTRACT

CONTEXT: The essential omega-3 fatty acids (ω-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibit vital biological roles and are critical for cardiovascular and neurologic health. Compared with the general population, football athletes may be at an increased risk of cardiovascular disease. Further, those same athletes are also exposed to repetitive head impacts, which may lead to long-term neurologic deficits. Both diets high in ω-3 FAs and supplementation with ω-3 FAs have been reported to reduce the risk of cardiovascular disease, and early evidence suggests a potential neuroprotective effect of supplementation. OBJECTIVE: To determine the (1) erythrocyte content of DHA and EPA, as measured by the Omega-3 Index, expressed as a percentage of total fatty acids, in National Collegiate Athletic Association Division I football athletes and (2) distribution across the Omega-3 Index risk zones established for cardiovascular disease: high risk, <4%; intermediate risk, 4% to 8%; and low risk, >8%. DESIGN: Cross-sectional descriptive study. SETTING: Multicenter trial. PATIENTS OR OTHER PARTICIPANTS: Deidentified data including complete erythrocyte fatty acid profile from the 2017-2018 season, age at time of testing, height, weight, and ethnicity were collected from 404 athletes. MAIN OUTCOME MEASURE(S): Omega-3 Index. RESULTS: About 34% of athletes (n = 138) had an Omega-3 Index considered high risk (<4%), and 66% (n = 266) had a risk considered intermediate (4%-8%). None had a low-risk Omega-3 Index. CONCLUSIONS: The Omega-3 Index is a simple, minimally invasive test of ω-3 FA status. Our data indicate that football athletes may be deficient in the ω-3 FAs DHA and EPA. The fact that no athlete had an Omega-3 Index associated with low risk suggests football athletes may be at increased risk for cardiovascular disease in later life.


Subject(s)
Fatty Acids, Omega-3/metabolism , Football/physiology , Athletes , Cross-Sectional Studies , Diet , Docosahexaenoic Acids/metabolism , Eicosapentaenoic Acid/analogs & derivatives , Eicosapentaenoic Acid/metabolism , Erythrocytes/chemistry , Female , Humans , Male , Retrospective Studies , Universities , Young Adult
11.
Phys Sportsmed ; 47(2): 137-147, 2019 05.
Article in English | MEDLINE | ID: mdl-30369286

ABSTRACT

In the sport of rugby, athletes need a multitude of sport-specific skills along with endurance, power, and speed to optimize performance. Further, it is not unusual for athletes to play several competitive matches with insufficient recovery time. Rugby requires repeated bouts of high-intensity actions intermixed with brief periods of low-to-moderate active recovery or passive rest. Specifically, a match is characterized by repeated explosive activities, such as jumps, shuffles, and rapid changes of direction. To facilitate adequate recovery, it is necessary to understand the type of fatigue induced and, if possible, its underlying mechanisms. Common approaches to recovery may include nutritional strategies as well as active (active recovery) and passive recovery (water immersions, stretching, and massage) methods. However, limited research exists to support the effectiveness of each strategy as it related to recovery from the sport of rugby. Therefore, the main aim of the current brief review is to present the relevant literature that pertains to recovery strategies in rugby.


Subject(s)
Football/physiology , Rest/physiology , Athletic Performance/physiology , Cool-Down Exercise , Diet , Dietary Supplements , Humans , Massage , Muscle Stretching Exercises
12.
J Athl Train ; 53(12): 1200-1205, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30562055

ABSTRACT

CONTEXT: Treatment delays can be contributing factors in the deaths of American football athletes from exertional heat stroke. Ideally, clinicians begin cold-water immersion (CWI) to reduce rectal temperature (Trec) to <38.9°C within 30 minutes of collapse. If delays occur, experts recommend Trec cooling rates that exceed 0.15°C/min. Whether treatment delays affect CWI cooling rates or perceptual variables when football uniforms are worn is unknown. OBJECTIVE: To answer 3 questions: (1) Does wearing a football uniform and delaying CWI by 5 minutes or 30 minutes affect Trec cooling rates? (2) Do Trec cooling rates exceed 0.15°C/min when treatment delays have occurred and individuals wear football uniforms during CWI? (3) How do treatment delays affect thermal sensation and Environmental Symptoms Questionnaire responses? DESIGN: Crossover study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Ten physically active men (age = 22 ± 2 y, height = 183.0 ± 6.9 cm, mass = 78.9 ± 6.0 kg). INTERVENTION(S): On 2 days, participants wore American football uniforms and exercised in the heat until Trec was 39.75°C. Then they sat in the heat, with equipment on, for either 5 or 30 minutes before undergoing CWI (10.6°C ± 0.1°C) until Trec reached 37.75°C. MAIN OUTCOME MEASURE(S): Rectal temperature and CWI duration were used to calculate cooling rates. Thermal sensation was measured pre-exercise, postexercise, postdelay, and post-CWI. Responses to the Environmental Symptoms Questionnaire were obtained pre-exercise, postdelay, and post-CWI. RESULTS: The Trec cooling rates exceeded recommendations and were unaffected by treatment delays (5-minute delay = 0.20°C/min ± 0.07°C/min, 30-minute delay = 0.19°C/min ± 0.05°C/min; P = .4). Thermal sensation differed between conditions only postdelay (5-minute delay = 6.5 ± 0.6, 30-minute delay = 5.5 ± 0.7; P < .05). Environmental Symptoms Questionnaire responses differed between conditions only postdelay (5-minute delay = 27 ± 15, 30-minute delay = 16 ± 12; P < .05). CONCLUSIONS: Treatment delays and football equipment did not impair CWI's effectiveness. Because participants felt cooler and better after the 30-minute delay despite still having elevated Trec, clinicians should use objective measurements (eg, Trec) to guide their decision making for patients with possible exertional heat stroke.


Subject(s)
Body Temperature , Clothing , Heat Stress Disorders/therapy , Immersion , Adult , Athletes , Cold Temperature , Cross-Over Studies , Exercise/physiology , Female , Football/physiology , Heat Stroke/therapy , Hot Temperature , Humans , Hyperthermia, Induced , Male , Thermosensing , United States , Water , Young Adult
13.
J Strength Cond Res ; 32(1): 19-26, 2018 Jan.
Article in English | MEDLINE | ID: mdl-27820726

ABSTRACT

McIntosh, ND, Love, TD, Haszard, J, Osborne, H, and Black, KE. ß-hydroxy ß-methylbutyrate (HMB) supplementation effects on body mass and performance in elite male rugby union players. J Strength Cond Res 32(1): 19-26, 2018-Preseason is characterized by high training volumes with short recovery periods ß-hydroxy ß-methylbutyrate (HMB) has been postulated to assist with recovery. ß-hydroxy ß-methylbutyrate has been shown to improve strength and body composition among untrained groups; the benefits of HMB among trained populations are unclear because of the methodologies employed. This randomized control trail determined the effects of 11 weeks HMB supplementation on body mass and performance measures in 27 elite rugby players. ß-hydroxy ß-methylbutyrate group (n = 13), mean ± SD age 20.3 ± 1.2 years, body mass 99.6 ± 9.1 kg; placebo group (n = 14), age 21.9 ± 2.8 years body mass 99.4 ± 13.9 kg for placebo. During the supplementation period, body mass increased with HMB 0.57 ± 2.60 kg but decreased with placebo 1.39 ± 2.02 kg (p = 0.029). There were no significant differences in any of the 4 strength variables (p > 0.05). However, on the yo-yo intermittent recovery test (YoYo IR-1), the placebo group improved 4.0 ± 2.8 levels but HMB decreased 2.0 ± 3.0 levels (p = 0.003). The results of this study suggest that HMB could be beneficial for gaining or maintaining body mass during periods of increased training load. However, it appears that HMB may be detrimental to intermittent running ability in this group although further research is required before firm conclusions can be made. Only 6 participants on HMB managed to complete both YoYo IR-1 tests because of injury, a larger sample size is required to fully investigate this potentially negative effect. Further, the mechanisms behind this decrement in performance cannot be fully explained and requires further biochemical and psychological investigation.


Subject(s)
Athletic Performance/physiology , Body Mass Index , Dietary Supplements , Football/physiology , Valerates/pharmacology , Body Composition/drug effects , Double-Blind Method , Humans , Male , Muscle Strength/drug effects , Muscle, Skeletal/drug effects , Valerates/administration & dosage , Young Adult
14.
Int J Sport Nutr Exerc Metab ; 28(1): 1-9, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-28771064

ABSTRACT

Vitamin D insufficiency is common in athletes and may lower physical performance. Many cross-sectional studies associate vitamin D status with physical performance in athletes; however, there have been few prospective randomized controlled trials with adequate statistical power to test this relationship, and none in the southern hemisphere. Thus, a prospective double-blind, randomized, placebo-controlled intervention trial was conducted involving 57 professional rugby union players in New Zealand. Participants were randomized to receive 50,000 IU of cholecalciferol (equivalent to 3,570 IU/day) or placebo once every two weeks over 11-12 weeks. Serum 25(OH)D concentrations and physical performance were measured at baseline, weeks 5-6, and weeks 11-12. Mean (SD) serum 25(OH)D concentrations for all participants at baseline was 94 (18) nmol/L, with all players above 50 nmol/L. Vitamin D supplementation significantly increased serum 25(OH)D concentrations compared to placebo, with a 32 nmol/L difference between groups at 11-12 weeks (95% CI, 26-38; p < 0.001). Performance in five of the six tests at study completion, including the primary outcome variable of 30-m sprint time, did not differ between the vitamin D supplemented and placebo groups (p > 0.05). Performance on the weighted reverse-grip chin up was significantly higher in players receiving vitamin D compared with placebo, by 5.5 kg (95% CI, 2.0-8.9; p = 0.002). Despite significantly improving vitamin D status in these professional rugby union players, vitamin D supplementation had little impact on physical performance outcomes. Thus, it is unlikely that vitamin D supplementation is an ergogenic aid in this group of athletes.


Subject(s)
Athletic Performance/physiology , Cholecalciferol/administration & dosage , Dietary Supplements , Football/physiology , Sports Nutritional Physiological Phenomena , Cholecalciferol/blood , Double-Blind Method , Humans , Male , New Zealand , Performance-Enhancing Substances , Young Adult
15.
Medicine (Baltimore) ; 96(7): e6146, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28207546

ABSTRACT

BACKGROUND: This single-blinded, three-armed randomized controlled trial aimed to compare the effects of postexercise ice-water immersion (IWI), room-temperature water immersion (RWI), and no water immersion on the balance performance and knee joint proprioception of amateur rugby players. METHODS: Fifty-three eligible amateur rugby players (mean age ±â€Šstandard deviation: 21.6 ±â€Š2.9 years) were randomly assigned to the IWI group (5.3 °C), RWI group (25.0 °C), or the no immersion control group. The participants in each group underwent the same fatigue protocol followed by their allocated recovery intervention, which lasted for 1 minute. Measurements were taken before and after the fatigue-recovery intervention. The primary outcomes were the sensory organization test (SOT) composite equilibrium score (ES) and the condition-specific ES, which were measured using a computerized dynamic posturography machine. The secondary outcome was the knee joint repositioning error. Two-way repeated measures analysis of variance was used to test the effect of water immersion on each outcome variable. RESULTS: There were no significant within- and between-group differences in the SOT composite ESs or the condition-specific ESs. However, there was a group-by-time interaction effect on the knee joint repositioning error. It seems that participants in the RWI group had lower errors over time, but those in the IWI and control groups had increased errors over time. The RWI group had significantly lower error score than the IWI group at postintervention. CONCLUSION: One minute of postexercise IWI or RWI did not impair rugby players' sensory organization of balance control. RWI had a less detrimental effect on knee joint proprioception to IWI at postintervention.


Subject(s)
Cold Temperature , Football/physiology , Hydrotherapy/methods , Lower Extremity/physiopathology , Muscle Fatigue/physiology , Proprioception/physiology , Adolescent , Adult , Exercise/physiology , Humans , Ice , Male , Single-Blind Method , Young Adult
16.
Sports Med ; 47(8): 1515-1530, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28150163

ABSTRACT

The physical demands and combative nature of rugby lead to notable levels of muscle damage. In professional rugby, athletes only have a limited timeframe to recover following training sessions and competition. Through the implementation of recovery strategies, sport scientists, practitioners and coaches have sought to reduce the effect of fatigue and allow athletes to recover faster. Although some studies demonstrate that recovery strategies are extensively used by rugby athletes, the research remains equivocal concerning the efficacy of recovery strategies in rugby. Moreover, given the role of inflammation arising from muscle damage in the mediation of protein synthesis mechanisms, some considerations have been raised on the long-term effect of using certain recovery modalities that diminish inflammation. While some studies aimed to understand the effects of recovery modalities during the acute recovery phase (<48 h post-match), others investigated the effect of recovery modalities during a more prolonged timeframe (i.e. during a training week). Regarding the acute effectiveness of different recovery modalities, cold water immersion and contrast baths seem to provide a beneficial effect on creatine kinase clearance, neuromuscular performance and delayed onset of muscle soreness. There is support in the literature concerning the effect of compression garments on enhancing recovery from delayed onset of muscle soreness; however, conflicting findings were observed for the restoration of neuromuscular function with the use of this strategy. Using a short-duration active recovery protocol seems to yield little benefit to recovery from rugby training or competition. Given that cold modalities may potentially affect muscle size adaptations from training, their inclusion should be treated with caution and perhaps restricted to certain periods where athlete readiness is more important than increases in muscle size.


Subject(s)
Football/physiology , Muscle Fatigue/physiology , Myalgia/therapy , Athletes , Athletic Performance , Creatine Kinase/blood , Fatigue , Humans , Hydrotherapy
17.
J Strength Cond Res ; 31(4): 888-892, 2017 Apr.
Article in English | MEDLINE | ID: mdl-26121431

ABSTRACT

Behara, B and Jacobson, BH. Acute effects of deep tissue foam rolling and dynamic stretching on muscular strength, power, and flexibility in Division I linemen. J Strength Cond Res 31(4): 888-892, 2017-A recent strategy to increase sports performance is a self-massage technique called myofascial release using foam rollers. Myofascial restrictions are believed to be brought on by injuries, muscle imbalances, overrecruitment, and/or inflammation, all of which can decrease sports performance. The purpose of this study was to compare the acute effects of a single-bout of lower extremity self-myofascial release using a custom deep tissue roller (DTR) and a dynamic stretch protocol. Subjects consisted of NCAA Division 1 offensive linemen (n = 14) at a Midwestern university. All players were briefed on the objectives of the study and subsequently signed an approved IRB consent document. A randomized crossover design was used to assess each dependent variable (vertical jump [VJ] power and velocity, knee isometric torque, and hip range of motion was assessed before and after: [a] no treatment, [b] deep tissue foam rolling, and [c] dynamic stretching). Results of repeated-measures analysis of variance yielded no pretest to posttest significant differences (p > 0.05) among the groups for VJ peak power (p = 0.45), VJ average power (p = 0.16), VJ peak velocity (p = 0.25), VJ average velocity (p = 0.23), peak knee extension torque (p = 0.63), average knee extension torque (p = 0.11), peak knee flexion torque (p = 0.63), or average knee flexion torque (p = 0.22). However, hip flexibility was statistically significant when tested after both dynamic stretching and foam rolling (p = 0.0001). Although no changes in strength or power was evident, increased flexibility after DTR may be used interchangeably with traditional stretching exercises.


Subject(s)
Football/physiology , Muscle Strength/physiology , Muscle Stretching Exercises/methods , Range of Motion, Articular/physiology , Therapy, Soft Tissue/methods , Adolescent , Athletes , Athletic Performance/physiology , Hip Joint/physiology , Humans , Knee Joint/physiology , Lower Extremity/physiology , Male , Muscle, Skeletal/physiology , Torque , Young Adult
18.
J Strength Cond Res ; 30(12): 3329-3338, 2016 12.
Article in English | MEDLINE | ID: mdl-27050245

ABSTRACT

Pinto, HD, Vanin, AA, Miranda, EF, Tomazoni, SS, Johnson, DS, Albuquerque-Pontes, GM, de Oliveira Aleixo Junior, I, Grandinetti, VdS, Casalechi, HL, de Tarso Camillo de Carvalho, P, and Pinto Leal Junior. Photobiomodulation therapy improves performance and accelerates recovery of high-level rugby players in field test: A randomized, crossover, double-blind, placebo-controlled clinical study. J Strength Cond Res 30(12): 3329-3338, 2016-Although growing evidence supports the use of photobiomodulation therapy (PBMT) for performance and recovery enhancement, there have only been laboratory-controlled studies. Therefore, the aim of this study was to analyze the effects of PBMT in performance and recovery of high-level rugby players during an anaerobic field test. Twelve male high-level rugby athletes were recruited in this randomized, crossover, double-blinded, placebo-controlled trial. No interventions were performed before the Bangsbo sprint test (BST) at familiarization phase (week 1); at weeks 2 and 3, pre-exercise PBMT or placebo were randomly applied to each athlete. Photobiomodulation therapy irradiation was performed at 17 sites of each lower limb, employing a cluster with 12 diodes (4 laser diodes of 905 nm, 4 light emitting diodes [LEDs] of 875 nm, and 4 LEDs of 640 nm, 30 J per site, manufactured by Multi Radiance Medical). Average time of sprints, best time of sprints, and fatigue index were obtained from BST. Blood lactate levels were assessed at baseline, and at 3, 10, 30, and 60 minutes after BST. Athletes' perceived fatigue was also assessed through a questionnaire. Photobiomodulation therapy significantly (p ≤ 0.05) improved the average time of sprints and fatigue index in BST. Photobiomodulation therapy significantly decreased percentage of change in blood lactate levels (p ≤ 0.05) and perceived fatigue (p ≤ 0.05). Pre-exercise PBMT with the combination of super-pulsed laser (low-level laser), red LEDs, and infrared LEDs can enhance performance and accelerate recovery of high-level rugby players in field test. This opens a new avenue for wide use of PBMT in real clinical practice in sports settings.


Subject(s)
Athletic Performance/physiology , Fatigue/rehabilitation , Football/physiology , Low-Level Light Therapy , Adult , Cross-Over Studies , Double-Blind Method , Fatigue/physiopathology , Humans , Lactic Acid/blood , Lower Extremity/physiology , Male , Muscle Fatigue , Muscle, Skeletal/physiopathology , Physical Exertion , Recovery of Function , Running/physiology , Young Adult
19.
Int J Sports Physiol Perform ; 11(2): 214-20, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26182441

ABSTRACT

PURPOSE: Caffeine can be beneficial during endurance and repeated-sprint exercise in able-bodied individuals performing leg or whole-body exercise. However, little evidence exists regarding its effects during upper-body exercise. This study therefore aimed to investigate the effects of caffeine on sprint (SPR) and 4-min maximal-push (PUSH) performance in wheelchair sportsmen. METHODS: Using a double-blind, placebo-controlled, crossover design, 12 male wheelchair rugby players (age 30.0 ± 7.7 y, body mass 69.6 ± 15.3 kg, training 11.1 ± 3.5 h/wk) completed 2 exercise trials, separated by 7-14 d, 70 min after ingestion of 4 mg/kg caffeine (CAF) or dextrose placebo (PLA). Each trial consisted of four 4-min PUSHes and 3 sets of 3 × 20-m SPRs, each separated by 4 min rest. Participants responded to the Felt Arousal (a measure of perceived arousal), Feeling (a measure of the affective dimension of pleasure/displeasure), and rating-of-perceived-exertion (RPE) scales. Salivary caffeine secretion rates were measured. RESULTS: Average SPR times were faster during CAF than PLA during SPR 1 and SPR 2 (P = .037 and .016). There was no influence of supplementation on PUSHes 2-4 (P > .099); however, participants pushed significantly farther during PUSH 1 after CAF than after PLA (mean ± SD 677 ± 107 and 653 ± 118 m, P = .047). There was no influence of CAF on arousal or RPE scores (P > .132). Feeling scores improved over the course of the CAF trial only (P = .017) but did not significantly differ between trials (P > .167). Pre-warm-up (45 min postingestion) salivary CAF secretion rates were 1.05 ± 0.94 and 0.08 ± 0.05 µg/min for CAF and PLA, respectively. CONCLUSION: Acute CAF supplementation can improve both 20-m-sprint performance and a 1-off bout of short-term endurance performance in wheelchair sportsmen.


Subject(s)
Athletic Performance/physiology , Caffeine/administration & dosage , Football/physiology , Sports for Persons with Disabilities/physiology , Wheelchairs , Adult , Arousal , Athletes , Cross-Over Studies , Dietary Supplements , Disabled Persons , Double-Blind Method , Humans , Male , Physical Endurance/drug effects , Saliva/chemistry , Young Adult
20.
Int J Sport Nutr Exerc Metab ; 26(1): 1-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26132746

ABSTRACT

Increasing the frequency of protein consumption is recommended to stimulate muscle hypertrophy with resistance exercise. This study manipulated dietary protein distribution to assess the effect on gains in lean mass during a rugby preseason. Twenty-four developing elite rugby athletes (age 20.1 ± 1.4 years, mass 101.6 ± 12.0 kg; M ± SD) were instructed to consume high biological value (HBV) protein at their main meals and immediately after resistance exercise while limiting protein intake between meals. To manipulate protein intake frequency, the athletes consumed 3 HBV liquid protein supplements (22 g protein) either with main meals (bolus condition) or between meals (frequent condition) for 6 weeks in a 2 × 2 crossover design. Dietary intake and change in lean mass values were compared between conditions by analysis of covariance and correlational analysis. The dietary manipulation successfully altered the protein distribution score (average number of eating occasions containing > 20 g of protein) to 4.0 ± 0.8 and 5.9 ± 0.7 (p < .01) for the bolus and frequent conditions, respectively. There was no difference in gains in lean mass between the bolus (1.4 ± 1.5 kg) and frequent (1.5 ± 1.4 kg) conditions (p = .91). There was no clear effect of increasing protein distribution from approximately 4-6 eating occasions on changes in lean mass during a rugby preseason. However, other dietary factors may have augmented adaptation.


Subject(s)
Dietary Proteins/administration & dosage , Dietary Supplements , Football/physiology , Muscle, Skeletal/growth & development , Sports Nutritional Physiological Phenomena , Athletes , Body Composition , Cross-Over Studies , Diet , Energy Intake , Humans , Male , Meals , Resistance Training , Young Adult
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