Blood lactate removal during recovery at various intensities below the individual anaerobic threshold in triathletes

摘要

Aim. Optimal lactate removal was reported to occur at workrate between 30% and 70% VO_(2max). However, it has been recently recommended to quantify exercise intensity not in percentage of VO_(2max) but in relation to validated metabolic reference points such as the individual anaerobic threshold (IAT) and the individual ventilatory threshold (IVT). The purpose of this study was to examine the effect on lactate removal of different recovery workrates below the IAT defined calculating the difference (ΔT) between IAT and IVT, then choosing the IVT+50%ΔT, the IVT and the IVT-50%ΔT workrates. Methods. Eight male triathletes (VO_(2max) 69.7±4.7, VO_(2IAT) 52.9±4, VO_(2IVT) 41.1±4.7 mL·kg~(-1)·min~(-1)), after a 6-min treadmill run at 75% of difference between IAT and VO_(2max), performed in a random order the following 30-min recovery treatments: 1) run at IVT_(+50%ΔT), 2) at IVT, 3) at IVT_(-50%ΔT), 4) passive. Blood lactate was measured at 1, 3, 6, 9, 12, 15, 20, 25, 30 minutes of recovery. Results. All active recovery workrates (from 50±5% to 67±4% VO_(2max)) were within the range previously reported for optimal lactate removal, and significantly more efficient than passive recovery on lactate removal curve (% of accumulated lactate above rest value). However, significant differences (P < 0.01) were found among active recovery intensities: the IVT_(-50%ΔT) was the most efficient workrate from the 9th minute to 30th minute. Conclusion. In triathletes, the IVT_(-50%ΔT) was the optimal workrate for lactate removal; moreover none of the studied active workrate showed further lactate decrease after the 20th minute of recovery.