Faculty of Sport, Centre of Research, Education, Innovation and Intervention in Sport, University of Porto, Porto, Portugal.
Porto Biomechanics Laboratory, University of Porto, Porto, Portugal.
Int J Sports Med. 2020 May;41(5):318-327. doi: 10.1055/a-0975-9532. Epub 2020 Jan 23.
The anaerobic threshold (AnT) seems to be not only a physiologic boundary but also a transition after which swimmers technique changes, modifying their biomechanical behaviour. We expanded the AnT concept to a biophysical construct in the four conventional swimming techniques. Seventy-two elite swimmers performed a 5×200 m incremental protocol in their preferred swimming technique (with a 0.05 m·s increase and a 30 s interval between steps). A capillary blood samples were collected from the fingertip and stroke rate (SR) and length (SL) determined for the assessment of [La], SR and SL vs. velocity inflexion points (using the interception of a pair of linear and exponential regression curves). The [La] values at the AnT were 3.3±1.0, 3.9±1.1, 2.9±1 .34 and 4.5±1.4 mmol·l (mean±SD) for front crawl, backstroke, breaststroke and butterfly, and its corresponding velocity correlated highly with those at SR and SL inflection points (r=0.91-0.99, p<0.001). The agreement analyses confirmed that AnT represents a biophysical boundary in the four competitive swimming techniques and can be determined individually using [La] and/or SR/SL. Blood lactate increase speed can help characterise swimmers' anaerobic behaviour after AnT and between competitive swimming techniques.
无氧阈 (AnT) 似乎不仅是一个生理界限，也是游泳技术改变的转折点，改变了他们的生物力学行为。我们将 AnT 概念扩展到了四种常规游泳技术中的生物物理结构。72 名优秀游泳运动员以他们喜欢的游泳技术进行了 5×200m 递增协议（每次增加 0.05m·s，两次之间间隔 30 秒）。从指尖采集毛细血管血样，确定划频（SR）和划长（SL），以评估[La]、SR 和 SL 与速度拐点（使用一对线性和指数回归曲线的交点）。在 AnT 时，自由泳、仰泳、蛙泳和蝶泳的[La]值分别为 3.3±1.0、3.9±1.1、2.9±1.34 和 4.5±1.4mmol·l（平均值±SD），其对应的速度与 SR 和 SL 拐点高度相关（r=0.91-0.99，p<0.001）。一致性分析证实，AnT 是四种竞技游泳技术中的生物物理边界，可以分别使用[La]和/或 SR/SL 来确定。血乳酸增加速度可以帮助描述 AnT 后和竞技游泳技术之间游泳者的无氧行为。
