Nederveen Joshua P, Keir Daniel A, Love Lorenzo K, Rossiter Harry B, Kowalchuk John M
Canadian Centre for Activity and Aging, London, ON, Canada; School of Kinesiology, The University of Western Ontario, London, ON, Canada.
Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA; Faculty of Biological Sciences, University of Leeds, Leeds, UK.
Respir Physiol Neurobiol. 2017 Jan;235:62-70. doi: 10.1016/j.resp.2016.09.013. Epub 2016 Sep 28.
We examined the effect of heavy-intensity 'priming' exercise on the rate of adjustment of pulmonary O uptake (τV˙O) initiated from elevated intensities. Fourteen men (separated into two groups: τV˙O≤25s [Fast] or τV˙O>25s [Slow]) completed step-transitions from 20W to 45% lactate threshold (LT; lower-step, LS) and 45% to 90%LT (upper-step, US) performed (i) without; and (ii) with US preceded by heavy-intensity exercise (HUS). Breath-by-breath V˙O and near-infrared spectroscopy-derived muscle deoxygenation ([HHb+Mb]) were measured. Compared to LS, τV˙O was greater (p<0.05) in US in both Fast (LS, 19±4s; US, 30±4s) and Slow (LS, 25±5s; US, 40±11s) with τV˙O in US being lower (p<0.05) in Fast. In HUS, τV˙O in Slow was reduced (28±8s, p<0.05) and was not different (p>0.05) from LS or Fast group US. In Slow, τ[HHb+Mb] increased (p<0.05) in US relative to HUS; this finding coupled with a reduced τV˙O indicates a priming-induced improvement in matching of muscle O delivery-to-O utilization during transitions from elevated intensities in those with Slow but not Fast V˙O kinetics.
我们研究了高强度“预激活”运动对从较高强度开始的肺氧摄取调整速率（τV˙O）的影响。14名男性（分为两组：τV˙O≤25秒[快速组]或τV˙O>25秒[慢速组]）完成了从20瓦到45%乳酸阈（LT；下台阶，LS）以及从45%到90%LT（上台阶，US）的阶跃过渡，实验进行了（i）无预激活运动；以及（ii）在进行上台阶运动之前先进行高强度运动（HUS）。逐次呼吸测量了V˙O以及近红外光谱法测定的肌肉去氧情况（[HHb+Mb]）。与LS相比，快速组（LS，19±4秒；US，30±4秒）和慢速组（LS，25±5秒；US，40±11秒）在上台阶运动时的τV˙O均更大（p<0.05），且快速组上台阶运动时的τV˙O更低（p<0.05）。在HUS中，慢速组的τV˙O降低（28±8秒，p<0.05），与LS组或快速组的上台阶运动时的τV˙O无差异（p>0.05）。在慢速组中，与HUS相比，上台阶运动时的τ[HHb+Mb]增加（p<0.05）；这一发现与降低的τV˙O相结合，表明对于那些具有慢速而非快速V˙O动力学的人，预激活运动可改善从较高强度过渡期间肌肉氧输送与氧利用的匹配情况。
