Laboratory of Performance, Sport-Occupational Activities-Biology-Association, Lyon-Chassieu, France.
Society Sports and Physical Exercise Research Group (GIKAFIT), Department of Physical Education and Sport, Faculty of Education and Sport, University of the Basque Country (UPV/EHU), Portal de Lasarte, 71, 01007, Vitoria-Gasteiz, Spain.
Eur J Appl Physiol. 2024 Nov;124(11):3227-3240. doi: 10.1007/s00421-024-05520-4. Epub 2024 Jun 7.
To evaluate the agreement between the two Gas Exchange Thresholds (GETs = GET1 and GET2), identified by the conventional V-Slope method, and two Respiratory Frequency Thresholds (fTs = fT1 and fT2) obtained from a novel, low-cost, and simple method of breakpoint determination.
Fifty middle-aged males (age: 50-58 years; o: 37.5 ± 8.6 mL·Kg·min), either healthy or with chronic illnesses, underwent an incremental cycle exercise test to determine maximal oxygen uptake ( o/ o), GETs and fTs.
There were no statistical differences [P > 0.05; ES: 0.17 to 0.32, small] between absolute and relative (56-60% o) oxygen uptake ( o) values at GET1 with those obtained at fT1, nor between o values at GET2 with those at fT2 (76-78% o). Heart rate (HR) at fT1, and o and HR at fT2 showed very large correlations (r = 0.75-0.82; P < 0.001) and acceptable precision (SEE < 7-9%) in determination of their corresponding values at GET1 and GET2. The precision in the estimation of o at GET1 from fT1 was moderate (SEE = 15%), while those of power output at GET1 (SEE = 23%) and GET2 (SEE = 12%) from their corresponding fTs values were very poor to moderate.
HR at fT1 and o and HR at fT2, determined using a new objective and portable approach, may potentially serve as viable predictors of their respective GETs. This method may offer a simplified, cost-effective, and field-based approach for determining exercise threshold intensities during graded exercise.
评估传统 V -slope 法确定的两种气体交换阈值（GETs=GET1 和 GET2）与一种新的、低成本、简单的断点确定方法得出的两种呼吸频率阈值（fTs=fT1 和 fT2）之间的一致性。
50 名中年男性（年龄：50-58 岁；o：37.5±8.6 mL·Kg·min），无论健康与否，均进行递增式自行车运动试验以确定最大摄氧量（o/ o）、GETs 和 fTs。
绝对和相对（56-60% o）摄氧量（o）值在 GET1 时与 fT1 时，以及在 GET2 时与 fT2 时的 o 值之间均无统计学差异（P>0.05；ES：0.17 至 0.32，小）。fT1 时的心率（HR）和 fT2 时的 o 和 HR 与 GET1 和 GET2 时的相应值具有高度相关性（r=0.75-0.82；P<0.001）和可接受的精度（SEE<7-9%）。从 fT1 估计 GET1 时的 o 值的精度为中等（SEE=15%），而从相应的 fTs 值估计 GET1 时的功率输出（SEE=23%）和 GET2 时的功率输出（SEE=12%）的精度非常差到中等。
使用新的客观便携方法确定的 fT1 时的 HR 和 fT2 时的 o 和 HR 可能潜在地成为各自 GETs 的可行预测指标。这种方法可能提供一种简化、具有成本效益的基于现场的方法，用于在递增运动中确定运动强度阈值。
