目的:量化长时间循环对通气率的影响([公式:见正文]),呼吸频率(FR),和潮气量(VT)与中度到重度强度转换相关。
方法:14名经耐力训练的自行车运动员和铁人三项运动员(1名女性)完成了对中重强度转换的评估,确定为第一通气阈值(VT1),在中等强度循环前(PRE)和后(POST)两小时。功率输出,[公式:见正文],FR,与VT1相关的VT在PRE和POST后测定。
结果:如先前报道,从PRE到POST,VT1的功率输出显着下降了约10%。与VT1相关的[公式:见文本]从PRE到POST不变(72±12vs.69±13L.min-1,Δ-3±5L.min-1,Δ-4±8%,P=0.075),并且相对一致(受试者内的变异系数,5.4%[3.7%,8.0%])。与VT1相关的[公式:见正文]产生的FR增加(27.6±5.8vs.31.9±6.5呼吸。min-1,Δ4.3±3.1呼吸。min-1,Δ16±11%,P=0.0002)和室性心动过速降低(2.62±0.43vs.2.19±0.36L.breath-1,Δ-0.44±0.22L.breath-1,Δ-16±7%,P=0.0002)后。
结论:这些数据表明,在中度到重度强度转换时,长时间运动会改变通气参数,但[公式:见正文]保持稳定。实时监测[公式:见正文]可能是评估长时间运动过程中中到重强度过渡接近度的有用手段,值得进一步研究。
OBJECTIVE: To quantify the effects of prolonged cycling on the rate of ventilation ([Formula: see text]), frequency of respiration (FR), and tidal volume (VT) associated with the moderate-to-heavy intensity transition.
METHODS: Fourteen endurance-trained cyclists and triathletes (one female) completed an assessment of the moderate-to-heavy intensity transition, determined as the first ventilatory threshold (VT1), before (PRE) and after (POST) two hours of moderate-intensity cycling. The power output, [Formula: see text], FR, and VT associated with VT1 were determined PRE and POST.
RESULTS: As previously reported, power output at VT1 significantly decreased by ~ 10% from PRE to POST. The [Formula: see text] associated with VT1 was unchanged from PRE to POST (72 ± 12 vs. 69 ± 13 L.min-1, ∆ - 3 ± 5 L.min-1, ∆ - 4 ± 8%, P = 0.075), and relatively consistent (within-subject coefficient of variation, 5.4% [3.7, 8.0%]). The [Formula: see text] associated with VT1 was produced with increased FR (27.6 ± 5.8 vs. 31.9 ± 6.5 breaths.min-1, ∆ 4.3 ± 3.1 breaths.min-1, ∆ 16 ± 11%, P = 0.0002) and decreased VT (2.62 ± 0.43 vs. 2.19 ± 0.36 L.breath-1, ∆ - 0.44 ± 0.22 L.breath-1, ∆ - 16 ± 7%, P = 0.0002) in POST.
CONCLUSIONS: These data suggest prolonged exercise shifts ventilatory parameters at the moderate-to-heavy intensity transition, but [Formula: see text] remains stable. Real-time monitoring of [Formula: see text] may be a useful means of assessing proximity to the moderate-to-heavy intensity transition during prolonged exercise and is worthy of further research.