Hansen Ernst Albin, Ohnstad Ann Elisabeth
Department of Physical Performance, Norwegian School of Sport Sciences, P.O. 4014, Ullevål Stadion, 0806, Oslo, Norway.
Exp Brain Res. 2008 Apr;186(3):365-73. doi: 10.1007/s00221-007-1240-5. Epub 2007 Dec 11.
Freely chosen pedalling rate during cycling represents a voluntary rhythmic movement. It is unclear to what extent this is influenced by internal (e.g. loading on the cardiopulmonary system) and external (e.g. mechanical loading) conditions. It is also unclear just how robust a voluntary motor rhythm, the freely chosen pedalling rate, actually is. The present study investigated (N = 8) whether or not the freely chosen pedalling rate during submaximal cycling was affected by separate increases in loading on the cardiopulmonary system (changed by exposure to acute simulated altitude of 3,000 m above sea level) and mechanical loading (changed by exposure to increased power output and thereby pedal force). We also investigated (N = 7) whether or not the freely chosen pedalling rate and another voluntary motor rhythm, unimanual unloaded index finger tapping rate, shared common characteristics of steadiness and individuality over a 12-week period. Results showed that the freely chosen pedalling rate was unaffected by increased loading on the cardiopulmonary system at constant mechanical loading, and vice versa. Further, the pedalling rate was steady in the longitudinal perspective (as was the tapping rate), and like tapping rate, pedalling rate was highly individual. In total this indicated that freely chosen pedalling rate primarily is a robust innate voluntary motor rhythm, likely under primary influence of central pattern generators that again are minimally affected by internal and external conditions during submaximal cycling.
骑行过程中自由选择的蹬踏频率代表一种自主的节律性运动。目前尚不清楚这种运动在多大程度上受到内部因素(如心肺系统的负荷)和外部因素(如机械负荷)的影响。同样不清楚的是,自由选择的蹬踏频率这种自主运动节律实际上有多稳定。本研究调查了8名受试者在次最大强度骑行时,心肺系统负荷单独增加(通过暴露于海拔3000米的急性模拟高原环境来改变)和机械负荷单独增加(通过增加功率输出从而增加蹬踏力来改变)是否会影响自由选择的蹬踏频率。我们还调查了7名受试者在12周的时间里,自由选择的蹬踏频率和另一种自主运动节律——单手无负荷食指敲击频率,是否具有稳定性和个体性的共同特征。结果表明,在机械负荷不变的情况下,心肺系统负荷增加不会影响自由选择的蹬踏频率,反之亦然。此外,从纵向来看,蹬踏频率是稳定的(敲击频率也是如此),并且和敲击频率一样,蹬踏频率具有高度的个体性。总体而言,这表明自由选择的蹬踏频率主要是一种稳定的先天性自主运动节律,可能主要受中枢模式发生器的影响,而在次最大强度骑行过程中,中枢模式发生器受内部和外部条件的影响最小。