Effects of combined training on total ghrelin and tumor necrosis factor-α in obese middle-aged men

Abstract AIMS The aim of the present study was to investigate the effects of combined training (CT) on total ghrelin and tumor necrosis factor-α (TNF-α) levels in obese middle-aged individuals. METHODS Twenty two obese middle-aged men (49.32 ± 5.74 years; Body mass index: 30.88 ± 1.64 kg/m²) were randomly assigned to a combined training group (CTG, n = 12) or a control group (CG, n = 10). The CT consisted of aerobic (50-85% of VO2peak) and resistance (6-10 RM) training performed three times per week, 60 min per session for 24 weeks. The anthropometric measurements, cardiorespiratory test (VO2peak), maximal strength assessment (1RM) and plasma concentrations of total ghrelin and TNF-α were determined before (Pre) and after 24 weeks (Post) of the experimental period. RESULTS Decreases were found in body fat percentage (Δ% -19.8) and waist circumference (Δ% -2.8) for CTG at the Post moment as compared to the Pre moment. In addition, the CTG demonstrated increases for VO2peak (Δ% 13.4) and for 1-RM of bench press (Δ% 78.1), leg press (Δ% 22.3) and arm curl (Δ% 19.3) at the Post moment as compared to the Pre moment. However, total ghrelin levels remained unchanged for CTG and CG after the experimental period, while TNF-α levels increased for CG (p ≤ 0.05). CONCLUSION the CT protocol performed was not effective in repairing total ghrelin levels and was not correlated with changes in the TNF-α; however, the exercise training was able to improve body composition and functional capabilities and contained the worsening of systemic inflammation associated to obesity.

Determinação do máximo déficit acumulado de oxigênio: efeito da duração dos testes submáximos para predição da demanda de oxigênio / Determination of the maximum accumulated oxygen deficit: effects of the submaximal tests duration for prediction of oxygen demand

O objetivo do presente estudo foi verificar a influência de diferentes tempos de análise dos testes submáximos para determinação do máximo déficit acumulado de oxigênio (MAOD), adotando diferentes janelas de tempo 4-6min, 6-8min e 8-10min. Participaram do estudo 10 ciclistas com idade média de 27,5 ± 4,1 anos, massa corporal 74,4 ± 12,7kg e tempo médio de prática de 9,8 ± 4,7 anos. Os atletas realizaram um teste de esforço progressivo para determinação do consumo de oxigênio de pico (VO2pico) e quatro testes retangulares submáximos (60, 70, 80 e 90 por cento VO2pico) com 10min de duração para estimar os valores da demanda de O2 (DEO2). Os valores médios de VO2 obtidos nas cargas para o tempo 4-6min, 6-8min e 8 a 10min foram aplicados em uma regressão linear entre a intensidade e o consumo de O2 para cada janela de tempo. Os sujeitos realizaram ainda um teste retangular supramáximo (110 por cento VO2pico) para a quantificação do MAOD. Não foi constatada nenhuma diferença significativa no VO2 entre os diferentes períodos de tempo dos testes submáximos (P > 0,05). Da mesma forma, nenhuma diferença significativa foi constatada no DEAO2 e MAOD nos diferentes períodos de análise (P > 0,05). Verificou-se ainda que os valores de MAOD obtidos nos três intervalos de tempo apresentaram boa concordância e forte correlação. Dessa forma, os dados sugerem que os testes submáximos utilizados para gerar os valores do MAOD podem ser reduzidos ao menos nesse tipo de amostra e com a utilização de ciclossimulador.

The aim of this study was to investigate the influence of different assessment time periods of submaximal tests on the determination of the maximal accumulated oxygen deficit (MAOD), through the adoption of different time slots of 4 to 6, 6 to 8 and 8 to 10 min. Ten cyclists with mean age of 27.5 ± 4.1 years, body mass 74.4 ± 12.7 kg and time experience of 9.8 ± 4.7 years participated in this study. The athletes underwent an incremental exercise test to determine the peak oxygen consumption (VO2peak), and four submaximal constant work-load test sessions (60, 70, 80 and 90 percent VO2peak) of 10 min in order to estimate the O2 demand (DEO2). The mean VO2 values obtained on each constant work-load for the 4 to 6, 6 to 8 and 8 to 10 min time-periods intervals were used to perform a linear regression between the intensity and O2 consumption for each time-period. In addition, the subjects performed one supramaximal rectangular test (110 percent VO2peak) for the quantification of MAOD. There was no significant difference in VO2 between the different time-periods for all submaximal tests (P> 0.05). Similarly, no significant difference was found in DEAO2 and MAOD (P> 0.05). Furthermore, the values of MAOD for the three time-periods intervals showed good agreement and strong correlation. Thus, the data suggest that the submaximal tests used to estimate the values of MAOD can be reduced, at least in this type of sample, and with the use of a cycle simulator.