C-Reactive Protein and Skin Temperature of the lower limbs of Brazilian elite soccer players like load markers following three consecutive games.

The aim of the study was to compare the levels and relative responses of C-Reactive Protein (CRP) and Skin Temperature (Tsk) of the lower limbs (LLs) of elite soccer players following three consecutive games with short intervals (< 4 days). Eleven male professional athletes (age, 29.26 ± 4.52 years) from an Brazil elite team were evaluated, with measurements obtained before (Baseline), and at Post-Games times (24, 48 and 72h). CRP and Tsk levels at 24 h and 48 h Post-Games times were higher than Baseline levels (CRP, p < 0.001, d > 0.9; Tsk, p < 0.04, d > 0.58), additionally, the levels of these variables (CRP vs. Tsk) showed positive correlations (p < 0.05, rs = 0.60-0.88). The relative responses these variables were evaluated (Δ%CRP; Δ%Tsk). The 48h responses of Game 3 are respectively higher than 48 h responses of games 1 and 2, in Δ%CRP (p < 0.03; G3 vs. G1, r = 0.66; G3 vs. G2, r = 0.88) and in Δ%Tsk (p < 0.003; G3 vs. G1, r = 0.88; G3 vs. G2, r = 0.88). The 48 h Post-Game time seems to represent valuable contributions to understanding the development regarding the magnitude and duration of inflammatory processes associated with recovery. Additionally, the positive correlations that were verified allow an increase in the robustness of the analysis of the load of consecutive games through CRP and Tsk of the LLs. Then, these results indicate a physiological stress and a probable cumulative effect of the game loads due to short intervals (< 4 days), which is reinforced by the verified outcome of the Total Distance covered (G3 < G2, p = 0.003; r = 0.88). These findings can contribute to better load control and greater robustness of injury prevention programs.

Physiological responses during the long-distance race in the warm environment in runners: a pilot-study.

BACKGROUND: This study investigated the effects of warm temperature in the external environment on physiological response in self- pace during the long-distance race in runners and the association between the physiological index of endurance performance (i.e., speeds at ventilatory anaerobic threshold [VVAT], respiratory compensation [VRCP], maximum oxygen uptake [VVO2max], and running economy) and average pace for each 3-km during the 21-km race. METHODS: Five male recreational runners (mean±SE age 36.6±6.1 years; VO2 max: 59.2±7.9) were submitted to a 21-kilometers race in the outdoor environment using a portable metabolic analyzer. RESULTS: Our results showed a reduction in speed to kilometers 12, 15, 18 and 21 than kilometer 3 (P<0.05). The runners showed a decrease in both VO2 (mL/kg/min) and RER from kilometer 15 (P=0.001 and P=0.003, respectively). Regarding cardiovascular response, our data demonstrated a steady HR response from kilometer 6 to 21 (P=0.99). Otherwise, the runners showed a decrease in oxygen pulse from kilometer 9 than both kilometers 3 and 6 (P=0.001). During the race, the runners demonstrated a significant increase in body temperature compared to rest (P=0.001). The results of the correlation analysis between physiological index of endurance performance and average pace for each 3-km during the 21-km race showed significant correlation between VVAT and average pace for: 12-km (r=0.95; P=0.01), 15-km (r=0.89; P=0.05) and 21-km (r=0.86; P=0.04); VRCP and average pace for 3-km (r=0.88; P=0.05). CONCLUSIONS: Our findings demonstrated that the increase in body temperature in a warm environment during the 21-km race is associated with both cardiovascular and metabolic strain in runners. Concerning physiological markers of endurance performance, VVAT appears to be the best predictor of the average pace throughout the 21-km race in a warm environment in recreational runners.

Association Between Exercise-Induced Hyperthermia and Intestinal Permeability: A Systematic Review.

BACKGROUND: Prolonged and strenuous physical exercise increases intestinal permeability, allowing luminal endotoxins to translocate through the intestinal barrier and reach the bloodstream. When recognized by the immune system, these endotoxins trigger a systemic inflammatory response that may affect physical performance and, in severe cases, induce heat stroke. However, it remains to be elucidated whether there is a relationship between the magnitude of exercise-induced hyperthermia and changes in intestinal permeability. OBJECTIVE: In this systematic review, we evaluated whether an exercise-induced increase in core body temperature (T Core) is associated with an exercise-induced increase in intestinal permeability. METHODS: The present systematic review screened the MEDLINE/PubMed and Web of Science databases in September 2016, without any date restrictions. Sixteen studies that were performed in healthy participants, presented original data, and measured both the exercise-induced changes in T Core and intestinal permeability were selected. These studies assessed intestinal permeability through the measurement of sugar levels in the urine and measurement of intestinal fatty acid binding protein or lipopolysaccharide levels in the blood. RESULTS: Exercise increased both T Core and intestinal permeability in most of the 16 studies. In addition, a positive and strong correlation was observed between the two parameters (r = 0.793; p < 0.001), and a T Core exceeding 39 °C was always associated with augmented permeability. CONCLUSION: The magnitude of exercise-induced hyperthermia is directly associated with the increase in intestinal permeability.

Physical performance and environmental conditions: 2014 World Soccer Cup and 2016 Summer Olympics in Brazil.

This editorial is for the special issue "Temperature sciences in Brazil" of the journal Temperature. It focuses on the physical performance and environmental conditions during the 2014 World Cup and the coming 2016 Summer Olympics. It emphasizes that a hot and humid environment imposes a great challenge to the human thermoregulation system, can lead to performance decrements, and increases the risk of developing hyperthermia. Adequate hydration, acclimatization, and body cooling strategies are effective interventions to minimize the risks associated with exercise in the heat.

Effect of ACTN3 gene on strength and endurance in soccer players.

Sports efficiency in activities in which strength and speed are the determining factors has been associated to the ACTN3 gene, which is responsible for the expression of α-actinin-3. Soccer is a mainly aerobic sport because of its long duration, but the acute actions that define the game demand a lot of strength and speed. The purpose of the present study was to compare the performance capacity of soccer players with different genotype groups of ACTN3 (XX, RX, and RR) in strength, speed, and endurance tests. Two hundred professional players of Brazilian soccer first division teams participated in this study. Speed, jump, and endurance test results were compared with the polymorphisms of the ACTN3 gene. It was noticed that RR individuals spent less time to run a 10-m path, compared with XX individuals (p < 0.05). The RR individuals also presented lower time rates at the 20- and 30-m path, compared with RX and XX individuals (p < 0.05). In jump tests, RR individuals presented higher rates, compared with RX and XX individuals (p < 0.05). As for aerobic tests, the XX individuals presented higher rates of V[Combining Dot Above]O2 max, compared with the RR group (p < 0.05), and did not differ from the RX group. The main conclusion of this study is that soccer players of genotype ACTN3/RR are the fastest in short distances and present higher jump potential. ACTN3/XX individuals presented the highest aerobic capacity. These findings can be used in training load adjustment and can influence the development of tactical schemes in soccer matches.