To further explain the absence of difference in blood glucose between conditions, it has been reported that as exercise intensity increases CHO oxidation increases as well lowering blood glucose . To illustrate, Gomes et al. reported no significant change in blood glucose level following prolonged tennis match play (197 min), which was accompanied by an increase
in blood cortisol. This selleck chemicals maintenance of blood glucose with an increased cortisol concentration is quite possibly associated with the activation of gluconeogenesis and glycogenolysis . These factors suggest the possibility that cortisol release might activate gluconeogenesis eliciting the maintenance of blood glucose. Ultimately, the lack of difference in blood glucose between conditions yielded similar patterns of performance during both trails (CHO vs. PLA). Therefore, it is possible that the metabolic demands PSI-7977 in vitro of tennis are not sufficient to significantly alter blood glucose during tennis match play to warrant supplementation with CHO . Even though CHO supplementation is often used to spare muscle glycogen stores during prolonged exercise, as performance seems to be impaired by low CHO availability Belnacasan clinical trial [2, 3, 20, 26, 36] that did not seem to be the
case in the present study. However, prolonged exercise (> 90 min at 55–75% of maximum oxygen uptake – VO2max) does seem to decrease blood glucose and muscle glycogen stores [20, 26]. Therefore, it is worth noting that as the results of the present investigation demonstrated a trend toward higher blood glucose level in the CHO condition, one may speculate that decrement in blood glucose concentration could reach significance during a second match performed with less than 24 hours of rest interval, leading to deleterious performance effects. These data, make it is reasonable to presume that CHO supplementation may be beneficial to maintain blood glucose level and augment performance
under tournament conditions (i.e. ATP, Challengers, Future and national tournaments), when matches are performed within 24 hours as a moderate impairment either of glycogen stores during the initial match may cause a drop in blood glucose in the subsequent match . CHO supplementation during exercise may have several benefits including an attenuation in central fatigue; a better maintenance of blood glucose and CHO oxidation rate an improved muscle glycogen sparing effect; a reduced exercise-induced strain; and a better maintenance of excitation-contraction coupling . The maintenance of blood glucose might delay fatigue by attenuating the rise in free fatty acids. This process may convincingly limit the increase of precursors related to central fatigue (i.e. serotonin) [37, 38].