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Purpose: To examine nocturnal sleep patterns, napping behaviors, and subjective wellness responses of elite water polo players within an in-season week and to identify whether sleeping patterns differ between men and women. Methods: Sleep characteristics of 10 male and 17 female professional water polo players were objectively assessed during 1 week of the in-season period, including 5 training days, 1 match day, and 1 day of rest. Internal load (rating of perceived exertion × duration of training or match) was assessed 30 minutes posttraining or postmatch, and the total quality of recovery was recorded every morning. A series of multilevel models were used to analyze the data. Results: Time in bed and wake-up time were earlier on both training (P <.001) and rest days (P <.001) than on the day of the match. Internal workload did not predict any of the players' sleeping patterns. Midday naps predicted less time in bed (P =.03) and likely less sleep time (P =.08). The total quality of recovery was predicted only by the total sleep time (P <.01). Women exhibited higher sleep efficiency (P <.001), less waking after sleep onset (P =.01), and a lower number of awakenings (P =.02) than men. Conclusions: The current results indicate that the nocturnal sleep patterns of elite water polo players are not associated with internal load and that women display better nocturnal sleep quality compared with men. As long naps interfere with nocturnal sleep, and total nocturnal sleep time predicts total quality of recovery, we suggest that athletes follow hygiene sleep strategies to facilitate adequate nocturnal sleep and next-day recovery. [ABSTRACT FROM AUTHOR]

Dietary protein with adequate essential amino acids effectively stimulates protein synthesis and improves muscle mass. Musculoskeletal disorders in lower or upper limbs are not uncommon among patients with type II diabetes mellitus (T2DM). Therefore, this study primarily examines the effects of chronic dietary protein manipulation on amino acids' profile and position sense in the elderly suffering from T2DM. A total of 26 individuals suffering from non-insulin-dependent T2DM (age > 55 years old) participated in a 12 week nutritional intervention. The subjects were randomly assigned and the control group received 0.8–1.0 g protein/kg/day, while the intervention group received 1.2–1.5 g protein/kg/day. Lean body mass, muscle strength, and position sense were assessed at baseline, as well as at the 6th and 12th week of the intervention. Only in the intervention group, the essential amino acids intake met the current nutritional recommendations (p < 0.05), while, by the 12th week, only the intervention group showed significant improvement in the muscle strength of knee (p < 0.05) and shoulder (p < 0.05) extension. On the contrary, in the control group, a significant decline in appendicular lean mass (p < 0.05) was observed by the 12th week. Position sense at the knee joint revealed a tendency for improvement in the intervention group by the 12th week (main effect of time p = 0.072). In the present investigation, it was revealed that the higher protein intake in the intervention group seemed to have positive effects on muscle strength and nearly positive effects on position sense. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to elucidate whether exercise intolerance with muscle blood flow restriction is located within the central nervous system or the heart, namely whether cardiac response constitutes the crucial point precipitating exercise cessation. Muscle blood flow restriction (venous occlusion) during whole-body dynamic exercise compared to control condition, accelerates: (a) the rate of skeletal muscle deoxygenation, (b) the increase in systolic blood pressure (c) the rating of perceived exertion; and (d) cerebral activation, without these variables will be different at exhaustion point between the two experimental conditions, despite a marked decrease in maximal exercise time and maximal aerobic output. Maximal cardiac responses (i.e., heart rate, stroke volume, and cardiac output) were also significantly limited with muscle blood flow restriction. These findings suggest that skeletal muscle oxygenation levels in combination with augmented blood pressure response and cerebral activation may be important determinants in setting the limits of exercise performance. Specifically, when the aforementioned variables reach a predetermined maximal level, exercise ability might be limited despite the fact that cardiac performance never ends up at peak values. Muscle blood flow restriction might simulate pathological conditions such as heart failure, hypertension, and peripheral vascular diseases, which are all characterized by skeletal muscle perfusion impairments, and, thus provide insights into exercise intolerance in health and disease. This study aimed to elucidate whether muscle blood flow restriction during maximal exercise is associated with alterations in hemodynamics, cerebral oxygenation, cerebral activation, and deterioration of exercise performance in male participants. Thirteen healthy males, cyclists (age 33 ± 2 yrs., body mass: 78.6 ± 2.5 kg, and body mass index: 25.57 ± 0.91 kg·m−1), performed a maximal incremental exercise test on a bicycle ergometer in two experimental conditions: (a) with muscle blood flow restriction through the application of thigh cuffs inflated at 120 mmHg (with cuffs, WC) and (b) without restriction (no cuffs, NC). Exercise performance significantly deteriorated with muscle blood flow restriction, as evidenced by the reductions in V ˙ O2max (−17 ± 2%, p < 0.001), peak power output (−28 ± 2%, p < 0.001), and time to exhaustion (−28 ± 2%, p < 0.001). Muscle oxygenated hemoglobin (Δ[O2Hb]) during exercise declined more in the NC condition (p < 0.01); however, at exhaustion, the magnitude of muscle oxygenation and muscle deoxygenation were similar between conditions (p > 0.05). At maximal effort, lower cerebral deoxygenated hemoglobin (Δ[HHb]) and cerebral total hemoglobin (Δ[THb]) were observed in WC (p < 0.001), accompanied by a lower cardiac output, heart rate, and stroke volume vs. the NC condition (p < 0.01), whereas systolic blood pressure, rating of perceived exertion, and cerebral activation (as assessed by electroencephalography (EEG) activity) were similar (p > 0.05) between conditions at task failure, despite marked differences in exercise duration, maximal aerobic power output, and V ˙ O2max. In conclusion, in trained cyclists, muscle blood flow restriction during an incremental cycling exercise test significantly limited exercise performance. Exercise intolerance with muscle blood flow restriction was mainly associated with attenuated cardiac responses, despite cerebral activation reaching similar maximal levels as without muscle blood flow restriction. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the relationship of 2 different field tests for the assessment of aerobic fitness in soccer players with the multistage 20-m test used for the evaluation of maximum oxygen uptake. Nineteen semi-professional male soccer players (age: 22.8 [+ or -] 2.5 mean [+ or -] SD) performed, under similar conditions, 3 field tests in a counterbalanced order 7 days apart. These tests were the multistage 20-m shuttle run test (MSRT), the Bangsbo test, and the Hoff test. Heart rate was recorded in all tests with telemetry, and the Borg scale was introduced at the end of exercise. Finally, 3-minute post-test lactate concentration was determined. Performance was 11.2 [+ or -] 0.9 levels in the MSRT, 1,658.9 [+ or -] 119.9 m in the Bangsbo test, and 1,798.2 [+ or -] 125.9 m in the Hoff test. There was a significant correlation between the Hoff test and performance in the MSRT (r = 0.49, p < 0.05). The Bangsbo test was not associated with the MSRT score (r = 0.26, p > 0.05). The maximum heart rate achieved in the Bangsbo test was significantly lower compared with that in the MSRT and Hoff test (Bangsbo: 186.6 [+ or -] 9.6, Hoff: 192 [+ or -] 7.6, MSRT: 190.4 [+ or -] 9.3 beats/min, p < 0.05). No difference was found in post-test lactate concentration among the 3 tests. In conclusion, the Hoff test can be used for the assessment of endurance in adult semi-professional soccer players. Coaches and teams could benefit from using the Hoff test that resembles soccer actions for the assessment of players' aerobic fitness. KEY WORDS soccer performance, field testing; multistage shuttle run test, Hoff test, Bangsbo test

Purpose : Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate test (WT) performed with the legs, but there are no data available concerning power production during a WT performed with the arms in handball players (HndP). Therefore, the purpose of this study was to explore the arm anaerobic profile of HndP during a WT. Methods: Twenty-one elite HndP and 9 physical education students (CON), performed a 30-s arm WT. Power production and muscle oxygenation were recorded. Results: Peak power (PP) as well as mean power (MP) was higher (P = .017 and 0.03, and ES = 1.00 and 0.86, respectively) for HndP (HndP PP: 7.6 ± 0.8 W·kg-1, CON PP: 6.7 ± 1.1 W·kg-1; HndP MP 5.3 ± 0.6 W·kg-1, CON MP 4.7 ± 0.9 W·kg-1) with no significant difference in fatigue index between the two groups. Muscle oxygen saturation (StO2) declined ∼30% with exercise with no differences between groups. During recovery the HndP group had higher StO2 (P = .01, ES= 3.04), total hemoglobin and oxygenated hemoglobin compared with the CON group (P < .01 ES = 3.29 and 0.99, respectively). StO2 returned to resting values in 29.5 ± 2.3 s in HndP, whereas this variable did not recover after 2 min in CON. Conclusions: The arm anaerobic capacity of the HndP was "excellent," significantly higher than that by the control group. Moreover, HndP exhibited faster recovery of StO2 compared with the control group. The greater power output and the faster muscle reoxygenation of arms in HndP can be attributed to specific training adaptations related to high performance in handball. [ABSTRACT FROM AUTHOR]

We investigated thermoregulatory and cardiovascular responses at rest in a temperate (20°C) and in a warm (30°C) environment (40% RH) without and with the application of capsaicin on the skin. We hypothesized that regardless of environmental temperature, capsaicin application would stimulate heat loss and concomitantly deactivate heat conservation mechanisms, thus resulting in rectal temperature (Tre) and mean blood pressure decline due to excitation of heat‐sensitive TRPV1. Ten male subjects were exposed, while seated, for 30 minutes to 20.8 ± 1.0°C or to 30.6 ± 1.1°C: without (NCA) and with (CA) application of capsaicin patches on the skin. Thermoregulatory (Tre, proximal‐distal skin temperature gradient) and cardiovascular variables (modelflow technique) as well as oxygen uptake were continuously measured. The area under the curve for Tre decline at 20°C was smaller in CA (−2.1 ± 1.3 a.u.) than in NCA (−0.6 ± 1.1 a.u., P < 0.01, r = 0.8). Likewise, at 30°C it was smaller in CA (−2.2 ± 2.1 a.u.) compared to NCA (−0.8 ± 2.0 a.u., P = 0.02, r = 0.7). Local vasomotor tone and oxygen uptake, were significantly lower by 36.7% ± 94.2% and 12.3% ± 12.3%, respectively, with capsaicin compared to NCA (P = 0.05 and P < 0.01, respectively). Additionally, in 30°C CA mean arterial pressure was lower by 10.7% ± 5.9%, 8.9% ± 5.9%, and 10.6% ± 7.0% compared to 30°C NCA, 20°C NCA, and 20°C CA, respectively (P < 0.01, P = 0.02, and P < 0.01, respectively, d = 1.4‐1.8). In conclusion, capsaicin application on the skin induced vasodilation and Tre decline. At 30°C CA, thermal responses were accompanied by arterial hypotension most likely due to the interactive effects of both stressors (warm environment and capsaicin) on cutaneous vascular regulation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Habitual exposure to carbon dioxide (CO2) is expected, but it is not proven, to dull ventilatory sensitivity to CO2 by reducing hypercapnic ventilatory response (HCVR) as it is expressed by the slope of the derived response curve (CO2 sensitivity: δVE/δPetCO2). It was hypothesized that HCVR is decreased by repeated breath hold maximal efforts (RBHE) before and after apnea training in comparison with no training and the control condition. METHODS: Two groups of breath holders, a control (CBH) group and novices to breath hold activities (NBH), visited the laboratory on four different occasions. In the first visit, subjects performed a HCVR test, whereas in the second visit they completed five successive RBHE separated by 2-min intervals. Another HCVR test was performed 2 min after cessation of the last apnea. For the next 14 d, only the NBH group trained by performing daily five RBHE separated by 2-min intervals. Subsequently, in a third and a fourth condition, subjects repeated the experimental protocol of the second and first visit. RESULTS: Although breath hold time (BHT) increased after apnea training in the NBH group by ~46%, CO2 sensitivity slopes were not different among experimental conditions and groups (2.8 ± 0.3, 2.9 ± 0.4 L · min-1 · mmHg-1 in the CBH and 2.7 ± 0.5, 2.7 ± 0.3 L · min-1 · mmHg-1 in the NBH during the second and third visit, respectively). CONCLUSION: HCVR after five RBHE or 14 d of apnea training was not decreased despite the achieved BHT enhancement. Hypercapnic dullness of ventilation isa complex biological process which takes more than 14 d of training to develop. [ABSTRACT FROM AUTHOR]