Does weekly internal training load vary in professional soccer players?

Quantification of training load in professional soccer players have produced similar findings where team mean to weekly training load (w-TL) barely varies throughout the season. The aims of the present study were (a) to analyze respiratory and muscular weekly perceived exertion, and (b) to determine the variability during pre-season and in-season competitive period taking into account each player individually. Twenty-one professional soccer players belonging a 2nd Division soccer team participated in this study. Differentiated w-TL accumulated was quantified during 44-week of pre-season and season period (i.e., 6-week of pre-season and 38-week of season). The perceived level of exertion for leg local-muscular in weekly training load (w-TLmus) was higher (P &lt; 0.05) than perceived exertion for central-respiratory in weekly training load (w-TLres) both for pre-competition and for competition period. Moreover, larger w-TL during pre-competitive period than competitive period in w-TLres and w-TLmus were shown. The intra-player variability showed higher values during pre-competition period (CV: from 30.4 to 75.4% and from 15.3 to 76.9%) than competitive period (CV: from 21.2 to 46.1% and from 22.1 to 44.2%) in both w-TLres and w-TLmus, respectively. The current study suggest that soccer players manage loads in a different way during pre-season and in-season periods.针对职业足球运动员训练负荷的量化研究已得出相似结论：球队周均训练负荷（weekly training load, w-TL）在整个赛季中几乎无明显波动。本研究旨在完成两项目标：（1）分析呼吸与肌肉维度的周自觉用力程度；（2）以每名运动员为个体，探究赛季前期与赛季中赛事周期内的负荷变异性。本研究共纳入21名效力于足球次级联赛俱乐部的职业足球运动员，对赛季前及赛季共计44周（即6周赛季前期与38周赛季期）内按呼吸与肌肉维度区分的周累积训练负荷进行量化。结果显示，周腿部局部肌肉训练负荷（w-TLmus）的自觉用力程度，在赛季前期与赛事期均显著高于周中枢呼吸训练负荷（w-TLres，P<0.05）；此外，赛季前期的w-TLres与w-TLmus负荷水平均高于赛事期。个体内变异性分析表明，w-TLres与w-TLmus的赛季前期变异系数（CV）分别为30.4%~75.4%与15.3%~76.9%，均高于赛事期的21.2%~46.1%与22.1%~44.2%。本研究提示，足球运动员在赛季前期与赛事期的负荷调控策略存在显著差异。