Estimated energy expenditure and training intensity in young female artistic gymnasts

Abstract Aim: This study determined the energy expenditure and effort intensity of athletes during women's artistic gymnastics training sessions. Methods: Ten gymnasts (age 10.9 ± 1.7 years) performed a test to estimate the maximum rate of oxygen uptake (VO2max), during which the maximum heart rate (HRmax) was also obtained. The heart rate (HR) of these gymnasts was recorded during five training sessions and then used to estimate the exercise intensity and energy expenditure. Results: Mean duration of training sessions was 4.08 ± 0.42 h, with mean HR corresponding to 137 ± 8 bpm or 69.0 ± 3.5% of HRmax. Gymnasts spent less training time at 90-100% HRmax compared to the other HR ranges (p < 0.05). Time spent at 60-70% and 70-80% was higher compared to 80-90% HRmax (p = 0.012 and p = 0.001, respectively). The training impulse was 239.2 ± 35.4 AU. Estimated energy expenditure was 768.3 ± 168.5 kcal, metabolic rate was 3.1 ± 0.6 kcal/min, and the metabolic equivalent of task (MET) corresponded to 6.1 ± 0.6. Conclusion: Young gymnasts performed prolonged and moderate-intensity training sessions that generated high energetic demands. This information is beneficial to gymnasts since the coaching team can use the data to control the training load and prescribe a proper diet.

Intensidade de esforço em jogos oficiais e simulados de futsal feminino / Exercise intensity during official and simulated female futsal games

O objetivo principal deste estudo foi descrever as demandas de intensidade de esforço (IE) sustentadas por atletas de futsal feminino em partidas oficiais e simuladas. Trinta e uma jogadoras realizaram cinco partidas oficiais e 16 duas simuladas. Primeiramente, as mesmas executaram o Futsal Intermittent Endurance Test (FIET) para determinação do pico de velocidade (PV) e da frequência cardíaca máxima (FCMAXFIET). Na sequência, foi realizado o monitoramento da FC durante todos os jogos para obtenção da IE. Para comparar os valores de FC registrados nas partidas (oficial vs. simulada) utilizou-se o teste "t" de Student para dados pareados. O nível de significância foi fixado em p≤0,05. A FCMAXFIET (196±9 bpm) e FCMAXJOGO (197±8 bpm) apresentaram correlação muito alta (r=0,83; p<0,01), sem diferença significante (p=0,45). A IE sustentada durante as cinco partidas oficiais foi em torno de 91 % da FCMAXFIET. Adicionalmente, as atletas permaneceram durante 96,7 % e 69,7 % do tempo total dos jogos com a FC acima de 85 % e 90 % da FCMAXFIET, respectivamente. Nos dois simulados, a IE foi 90,6 %da FCMAXFIET, corroborando os dados das partidas oficiais monitoradas. Assim, a partir dos resultados deste estudo, destaca-se a elevada demanda fisiológica imposta às jogadoras, comprovando a necessidade de um nível superior de potência aeróbia máxima. Além disso, a IE nas partidas oficiais e simuladas foi semelhante, demonstrando que na modalidade os jogos simulados são uma importante estratégia para induzir um estresse fisiológico semelhante àquele solicitado nos oficiais.(AU)

The main purpose of this study was to describe the exercise intensity (EI) sustained by female athletes during official and simulated futsal games. Thirty one athletes played five official games, and 16 two simulated games. The athletes performed the Futsal Intermittent Endurance Test (FIET) to determine the peak velocity (PV) and maximum HR (HRMAXFIET). Following, the HR was monitored during the games to determine the exercise intensity demands. In order to compare the HR values between official and simulated games, Student´s t-test for paired sample was used. The level of confidence was set at 5% for all analyses. The HRMAXFIET (196 ± 9 bpm) and HRMAXGAME (197 ± 8 bpm) presented very high correlation (r = 0.83, p <0.01), with no significant difference (p = 0.45). In addition, the athletes spent 96.7% and 69.7% of the playing time with the HR above 85% and 90% of HRMAXFIET, respectively. In both simulated games, the EI was 90.6% of HRMAXFIET, confirming the HR values found during official matches. Thus, according to the results of the present study, it can be highlighted that there is a high physiological demand imposed on players during games, showing the importance of an enhanced level of maximal aerobic power for female futsal athletes. In addition, it was found that the EI in official and simulate games was similar, showing that the simulated games are an important strategy to induce similar physiological responses.(AU)

Biomarcadores de estresse em ratos exercitados por natação em intensidades igual e superior à máxima fase estável de lactato / Biomarkers of stress in rats exercised in swimming at intensities equal and superior to the maximal estable lactate phase

INTRODUÇÃO: O estresse alcançado durante exercício agudo/crônico é relevante, pois altos índices de estresse podem prejudicar o bem-estar dos animais. As concentrações dos hormônios adrenocorticotrófico (ACTH) e corticosterona, bem como as concentrações de ácido ascórbico e colesterol das glândulas adrenais são importantes biomarcadores de estresse. OBJETIVO: Analisar a sensibilidade de diferentes biomarcadores de estresse em ratos durante exercício agudo de natação em diferentes intensidades. MÉTODO: Ratos (18) adaptados à natação foram submetidos a três testes de 25 minutos suportando cargas 5,0; 5,5 e 6,0 por cento do peso corporal (PC), para obtenção da máxima fase estável de lactato (MFEL). Em seguida, os animais foram divididos em dois grupos: M (n = 9), sacrificado após 25 minutos de exercício na intensidade de MFEL e S (n = 9), sacrificado após exercício exaustivo, em intensidade 25 por cento superior a MFEL. Para comparações, um grupo controle C (n = 10) foi sacrificado em repouso. RESULTADOS: As concentrações séricas de ACTH e corticosterona foram superiores após exercício em ambas as intensidades comparadas com o grupo controle (P < 0,05). As concentrações de ACTH e corticosterona do grupo S foram, ainda, maiores do que as do grupo M (P < 0,05). As concentrações de colesterol e ácido ascórbico na adrenal dos grupos exercitados (M e S) foram inferiores às do grupo controle (P < 0,05). Não houve diferença das concentrações de ácido ascórbico e colesterol da adrenal quando comparadas as duas intensidades de exercício (M e S) (P < 0,05). CONCLUSÃO: Todos os biomarcadores do eixo HHA apontaram alterações no nível de estresse de ratos submetidos a exercício agudo de natação; as concentrações séricas de ACTH e corticosterona mostraram-se mais sensíveis a pequenas alterações na intensidade do exercício.

INTRODUCTION: The level of stress during acute/chronic exercise is important, since higher levels of stress may impair animal welfare. The adrenocorticotrophic (ACTH) and corticosterone hormone concentrations, as well as cholesterol and ascorbic acid concentrations in adrenal gland, are considered an important stress biomarker. PURPOSE: To analyze the sensitivity of the different biomarkers during acute swimming exercise in different intensities performed by rats. METHODS: Male Wistar adult rats (n = 18) previously adapted to swimming were submitted to three 25 min. swimming tests with loads of 5.0; 5.5 and 6.0 percent of their body weight (BW), for maximum lactate steady state (MLSS) determination. After MLSS attainment, the animals were divided into two groups: M (n = 9) sacrificed shortly after a 25 min. session of exercise at the MLSS intensity or S (n = 9) sacrificed after exhaustive exercise at intensity 25 percent above MLSS. For comparison purposes, a control group C (n = 10) was sacrificed in rest. RESULTS: Serum ACTH and corticosterone concentrations were higher after exercise for the two groups (M and S) when compared with control group C (P < 0.05). The group S presented higher concentrations for both hormones in relation to the group M (P < 0.05). The concentrations of the cholesterol and ascorbic acid in adrenal were lower after exercise for the two groups (M and S) when compared with control group C (P < 0.05). No significant differences in adrenal ascorbic acid and cholesterol levels were observed when the two exercise intensities (M and S) were compared (P < 0.05). CONCLUSION: All biomarkers of HPA activity pointed alterations in the stress level of the rats submitted to acute swimming exercise. ACTH and corticosterone serum concentrations showed to be more sensitive to small alterations in the effort intensity.