Department of Health Science, Lock Haven University of Pennsylvania, 401 N Fairview Street, Lock Haven, PA 17745, USA.
Eur J Appl Physiol. 2013 Apr;113(4):877-85. doi: 10.1007/s00421-012-2497-3. Epub 2012 Sep 21.
The purpose of this investigation was to describe the just noticeable difference (JND) in perceived exertion during cycle exercise. Males (n = 20) and females (n = 26) (21.4 ± 3.1 year) performed load-incremented cycle exercise to peak intensity. At the end of each minute, subjects rated their overall-body perceived exertion using the OMNI (0-10) rating of perceived exertion (RPE) scale. Individual regression derived the power output (PO) corresponding to RPE 5. This PO served as the standard stimulus (SS). On a separate occasion, four 5-min cycling bouts were performed with 5 min rest between bouts. During bouts 1 and 3 subjects cycled at the SS. During bouts 2 and 4 subjects adjusted the resistance to achieve a level of exertion just noticeably above/below the SS. The difference in final 30-s oxygen consumption (VO2) and PO between each JND bout and the previous SS were the above (JND-A) and below (JND-B) perceived exertion JNDs. JND-A and JND-B were compared between genders and between subjects exhibiting lower versus higher ventilatory threshold (VT) and VO(2PEAK) within genders for VO2 (l · min(-1), %VO(2PEAK)) and PO (W, %SS). JND-B was significantly (P < 0.05) greater than JND-A for VO2 and PO, when expressed in absolute (l · min(-1), W) and relative units (%VO(2PEAK), %SS). Males exhibited greater JND values than females in absolute, but not relative, units. Subjects with lower and higher VT and VO(2)PEAK exhibited similar JND values. The JND can serve as an effective tool to measure perceptual acuity and to determine individual ability to self-regulate prescribed exercise intensities.
本研究旨在描述在自行车运动中感知用力的可察觉差异（JND）。男性（n=20）和女性（n=26）（21.4±3.1 岁）进行递增负荷的自行车运动直至达到峰值强度。在每一分钟结束时，受试者使用 OMNI（0-10）等级感觉用力评估量表（RPE）来评定他们的全身感知用力。个体回归得出 RPE 为 5 时的功率输出（PO）。该 PO 用作标准刺激（SS）。在另一个场合，进行了四个 5 分钟的自行车回合，每个回合之间休息 5 分钟。在回合 1 和 3 中，受试者以 SS 进行骑行。在回合 2 和 4 中，受试者调整阻力以达到比 SS 略高/略低的用力水平。每个 JND 回合与前一个 SS 之间的最后 30 秒耗氧量（VO2）和 PO 的差异是高于（JND-A）和低于（JND-B）感知用力 JND。比较了性别之间以及在性别内，通气阈（VT）和 VO2PEAK 较低和较高的受试者之间的 JND-A 和 JND-B，以比较 VO2（l·min-1，%VO2PEAK）和 PO（W，%SS）。当以绝对值（l·min-1，W）和相对值（%VO2PEAK，%SS）表示时，VO2 和 PO 的 JND-A 和 JND-B 均显著（P<0.05）。男性在绝对值上的 JND 值大于女性，但在相对值上则不然。VT 和 VO2PEAK 较低和较高的受试者的 JND 值相似。JND 可以作为一种有效的工具来衡量感知敏锐度，并确定个体自我调节规定运动强度的能力。
