ABSTRACT
This study aimed to investigate recovery markers among elite climbers following the National Boulder Championship. We assessed maximum isometric hand grip strength (HS), forearm swelling (circumference), delayed soreness in forearm muscles, tiredness, and exercise readiness at several time points: pre-competition, immediately post-competition (within 4â min after their last effort), and 12, 24, 48, and 60â h post-competition. Maximum isometric hand grip strength decreased by 6.38 ± 1.32% (p = 0.006) post-12â h, returning to pre-competition values post-24â h (all p > 0.05). Forearm circumference (FC) increased 1.78 ± 1.77% (p < 0.001) post-competition, returning to pre-competition values post-12â h (all p > 0.05). Forearm pain (FP) increased post-competition (p = 0.002) and post-12â h (p < 0.001), returning to pre-competition values post-24â h (all p > 0.05). Tiredness increased post-competition (p < 0.001), post-12â h (p < 0.001), and post-24â h (p < 0.001), returning to pre-competition values post-48â h (all p > 0.05). Climbing readiness was reduced post-competition (p < 0.001), post-12â h (p < 0.001), post-24â h (p < 0.001), and post-48â h (p = 0.005), only returning to pre-competition values post-60â h (p = 0.189). Visual analysis of individual data pointed out a relatively small variability in the HS and FC markers, while FP, tiredness, and readiness exhibited larger individual variations. These findings indicate that different recovery patterns exist for the analyzed markers, suggesting that athletes may require up to 60â h after a competition to fully recover and regain their ability to face new competitive challenges.
ABSTRACT
The present study aimed to investigate the influence of months of birth on anthropometry, body composition, biological maturation, and motor performance in young Brazilian soccer players. Young Brazilian soccer players from the Under-13 (n = 50; 13.6 ± 0.3 years), Under-15 (n = 50; 15.5 ± 0.4 years), and Under-17 categories (n = 46; 17.7 ± 0.3 years) took part in this study. Athletes were divided according to chronological age, 1st tertile (January to April); 2nd tertile (May to August); and 3rd tertile (September to December). Anthropometry, body composition, biological maturation, and motor performance variables were evaluated for all participants. There were no differences between the U-13, U-15, and U-17 categories regarding birth tertiles (p > 0.05). Differences between the ages and birth tertiles were observed for the stature, body mass, and lean body mass (p < 0.05). Moreover, differences were found in maturational status between the ages and birth tertiles (p < 0.05). In general, U-13 players showed lower values compared to U-15 and U-17 players in tests of motor performance. In addition, there was a difference in motor performance between the birth tertiles only for RSA variables. The months of birth influenced the stature, body mass, lean body mass, and repeated sprint ability in the U-13 and U-15 categories. Thus, care should be taken during the process of talent selection, as many young players could be underestimated due to their date of birth.
ABSTRACT
The objective of the study was to investigate the effects of using lifting straps on the lat pull-down exercise on maximal strength, number of repetitions, and muscle activation. Twelve resistance-trained men participated (age 27 ± 4 years, body mass 84 ± 10 kg, height 177 ± 6 cm, resistance training experience 6.6 ± 2.4 years). All participants performed the 1RM tests and training protocols either with the lifting straps (WS) or without (WOS). Exercise sessions for both conditions (WS and WOS) consisted of 3 sets to concentric failure with a load of 70% of one repetition maximum (1RM) and rest intervals of 60 s. For the 1RM test, no difference was observed between WS and WOS conditions (96.5 ± 12.7 kg and 96.6 ± 11.9 kg, respectively). There were no differences between the WS and WOS conditions in the number of repetitions per set, total repetitions and latissimus dorsi muscle activation. In conclusion, the findings of this study demonstrate that the use of lifting straps in the lat pull-down exercise by resistance-trained individuals does not promote beneficial effect in the 1RM value, the number of repetitions performed with 70% of 1RM, and muscle activation.
Subject(s)
Hand Strength/physiology , Muscle Strength/physiology , Sports Equipment , Superficial Back Muscles/physiology , Weight Lifting/physiology , Adult , Biomechanical Phenomena , Cross-Over Studies , Electromyography , Humans , Male , Young AdultABSTRACT
This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.
Subject(s)
Exercise/physiology , Oxygen Consumption/physiology , Pulmonary Ventilation/physiology , Adult , Breathing Exercises/methods , Carbon Dioxide/blood , Exercise Test/methods , Female , Healthy Volunteers , Humans , Hypoxia/metabolism , Lung/metabolism , Male , Masks , Oxygen/blood , Respiration , Respiratory Function TestsABSTRACT
PURPOSE: To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. METHODS: Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg-1) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. RESULTS: Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. CONCLUSION: The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.
Subject(s)
Athletic Performance , Caffeine/pharmacology , Central Nervous System Stimulants/pharmacology , Exercise , Hypoxia/metabolism , Muscle Fatigue/drug effects , Adult , Caffeine/administration & dosage , Caffeine/adverse effects , Central Nervous System Stimulants/administration & dosage , Central Nervous System Stimulants/adverse effects , Humans , Male , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiologyABSTRACT
The aim of this study was to evaluate the effect of caffeine intake on critical power model parameters determined on a cycle ergometer. Eight male subjects participated in this study. A double-blind protocol consisting of the intake of pure caffeine (6 mg/kg) or placebo (maltodextrin) 60 min before testing was used. Subjects were submitted to four constant-load tests on a cycle ergometer. These tests were conducted randomly in the caffeine and placebo groups [checar] at intensities of 80, 90, 100 and 110% maximum power at a rate of 70 rpm until exhaustion to determine the critical power. As a criterion for stopping the test was adopted any rate fall without recovery by more than five seconds. The critical power and anaerobic work capacity were obtained by nonlinear regression and fitting of the curve to a hyperbolic power-time model. The Shapiro-Wilk test and paired Student t-test were used for statistical analysis. No significant differences in critical power were observed between the caffeine and placebo groups (192.9 ± 31.3 vs 197.7 ± 29.4 W, respectively). The anaerobic work capacity was significantly higher in the caffeine group (20.1 ± 5.2 vs 16.3 ± 4.2 W, p<0.01). A high association (r2) was observed between the caffeine and placebo conditions (0.98 ± 0.02 and 0.99 ± 0.0, respectively). We conclude that caffeine intake did not improve critical power performance but increased anaerobic work capacity by influencing performance at loads of higher intensity and shorter duration.
The aim of this study was to evaluate the effect of caffeine intake on critical power model parameters determined on a cycle ergometer. Eight male subjects participated in this study. A double-blind protocol consisting of the intake of pure caffeine (6 mg/kg) or placebo (maltodextrin) 60 min before testing was used. Subjects were submitted to four constant-load tests on a cycle ergometer. These tests were conducted randomly in the caffeine and placebo groups [checar] at intensities of 80, 90, 100 and 110% maximum power at a rate of 70 rpm until exhaustion to determine the critical power. As a criterion for stopping the test was adopted any rate fall without recovery by more than five seconds. The critical power and anaerobic work capacity were obtained by nonlinear regression and fitting of the curve to a hyperbolic power-time model. The Shapiro-Wilk test and paired Student t-test were used for statistical analysis. No significant differences in critical power were observed between the caffeine and placebo groups (192.9 ± 31.3 vs 197.7 ± 29.4 W, respectively). The anaerobic work capacity was significantly higher in the caffeine group (20.1 ± 5.2 vs 16.3 ± 4.2 W, p<0.01). A high association (r2) was observed between the caffeine and placebo conditions (0.98 ± 0.02 and 0.99 ± 0.0, respectively). We conclude that caffeine intake did not improve critical power performance but increased anaerobic work capacity by influencing performance at loads of higher intensity and shorter duration.