Draper S B, Wood D M
School of Sport and Leisure, University of Gloucestershire, Oxstalls Campus, Oxstalls Lane, Gloucester, GL2 9HW, UK.
Eur J Appl Physiol. 2005 Jan;93(4):381-9. doi: 10.1007/s00421-004-1278-z. Epub 2004 Nov 23.
Recent research in which data were averaged over 10 or 30 s suggests that the VO(2) response of aerobically fit individuals plateaus below VO(2 max) in an exhaustive square-wave run lasting approximately 2 min. To investigate this phenomenon we examined the breath-by-breath VO(2) response of trained runners to an exhaustive treadmill run at 800 m pace. Eight male competitive runners completed two treadmill tests on separate days: a ramp test to exhaustion and an exhaustive square-wave run at 800-m pace. For the ramp test, the breath-by-breath data were smoothed with a 15-s moving average and the highest of the smoothed values was taken as VO(2 peak) [mean (SD): 68.9 (5.6) ml kg(-1) min(-1)]. For the square-wave, the breath-by-breath data were interpolated to give one value per second and modelled using a monoexponential function. Following a delay of 11.2 (1.5) s, VO(2) increased quickly [phase-2 time constant of 10.7 (2.7) s] towards an asymptote that represented just 85 (6)% of VO(2 peak) from the ramp test. Expressed in ml kg(-1) min(-1), this asymptote was independent of VO(2 peak) (r=0.04, P=0.94). However, as a percentage of VO(2 peak) it was negatively correlated with VO(2 peak) itself (r=-0.96, P<0.001). It is concluded that in an exhaustive square-wave treadmill run lasting approximately 2 min the VO(2) of aerobically fit runners increases quickly to plateau at a level that is lower than, but independent of, VO(2max).
近期一项对数据进行10秒或30秒平均处理的研究表明，在持续约2分钟的力竭性方波跑中，有氧适能个体的VO₂反应在低于VO₂max时趋于平稳。为了研究这一现象，我们检测了训练有素的跑步者在以800米配速进行力竭性跑步机跑步时逐次呼吸的VO₂反应。八名男性竞技跑步者在不同日期完成了两项跑步机测试：一项渐增负荷至力竭测试和一项以800米配速进行的力竭性方波跑。对于渐增负荷测试，逐次呼吸数据采用15秒移动平均值进行平滑处理，并将平滑后的值中的最高值作为VO₂峰值[均值（标准差）：68.9（5.6）毫升·千克⁻¹·分钟⁻¹]。对于方波跑，逐次呼吸数据进行插值处理，以每秒给出一个值，并使用单指数函数进行建模。在延迟11.2（1.5）秒后，VO₂迅速增加[第二阶段时间常数为10.7（2.7）秒]，直至达到一个渐近线，该渐近线仅代表渐增负荷测试中VO₂峰值的85（6）%。以毫升·千克⁻¹·分钟⁻¹表示，该渐近线与VO₂峰值无关（r = 0.04，P = 0.94）。然而，作为VO₂峰值的百分比，它与VO₂峰值本身呈负相关（r = -0.96，P < 0.001）。研究得出结论，在持续约2分钟的力竭性方波跑步机跑步中，有氧适能跑步者的VO₂迅速增加，然后在低于VO₂max但与之无关的水平趋于平稳。
