Stones M J, Hartin Adric
a Department of Psychology , Lakehead University , Thunder Bay , Ontario , Canada.
Exp Aging Res. 2017 Mar-Apr;43(2):178-191. doi: 10.1080/0361073X.2017.1276378.
Background/Study Context: Previous research on triathlon performance analyzed age trends for the Top Ten or Top Five finishers in world championship or national races at Olympic, Half-Ironman, and Ironman distances. The findings indicated higher age declines and/or earlier onset of decline in swimming and running than cycling. However, the designs of those studies took no account of possible differences between cross-sectional and longitudinal trends (i.e., cohort differences versus age changes).
This study analyzed performance times over the inaugural 5 years of the Half-Ironman world championship held in Clearwater, Florida, from 2006 to 2010. Only one previous study is known that examined age trends in performance for this triathlon distance. The data from the official race results showed 5549 age class competitors that provided 6541 sets of observations. Analyses by mixed linear modeling (MLM) partitioned the data to compare discrete and interactive cross-sectional and longitudinal trends for swimming, cycling, and running, respectively.
The findings showed an historical decrease in cycling and running but not swimming times. Performance times were lower by men than women, with the gender discrepancy higher in some older age classes. Comparable to earlier findings for the Half-Ironman triathlon, cross-sectional performance decline was apparent for all triathlon activities from an early cohort age (i.e., 35-39 years). Although longitudinal trend showed significant gains for swimming, running, and overall times, interactions between cohort age and age change showed longitudinal decline that began at a younger cohort age for running (35-39 years) than swimming (50-55 years), but the interaction was nonsignificant for cycling. These interactions add to the knowledge about cohort differences and age changes in triathlon performance.
Practical applications of the findings suggest that conservation of effort might explain the absence of longitudinal change in cycling performance at older cohort ages. The authors reason that increased effort in cycling might benefit overall times of older triathletes.
背景/研究背景：先前关于铁人三项运动成绩的研究分析了世界锦标赛或全国性赛事中，在奥运会距离、半程铁人三项和全程铁人三项比赛中排名前十或前五的选手的年龄趋势。研究结果表明，游泳和跑步项目的年龄下降幅度更大和/或下降开始得更早，相比之下自行车项目则不然。然而，这些研究的设计没有考虑到横断面趋势和纵向趋势之间可能存在的差异（即队列差异与年龄变化）。
本研究分析了2006年至2010年在佛罗里达州克利尔沃特举行的半程铁人三项世界锦标赛首个五年的成绩时间。已知只有一项先前的研究考察了这个铁人三项距离项目的成绩年龄趋势。官方比赛结果数据显示，有5549名年龄组参赛者提供了6541组观测数据。通过混合线性模型（MLM）进行分析，将数据进行划分，分别比较游泳、自行车和跑步项目的离散和交互式横断面及纵向趋势。
研究结果显示，自行车和跑步项目的成绩有历史性下降，但游泳项目没有。男性的成绩时间比女性低，在一些较高年龄组中性别差异更大。与先前关于半程铁人三项的研究结果类似，从较早的队列年龄（即35 - 39岁）开始，所有铁人三项活动的横断面成绩下降都很明显。尽管纵向趋势显示游泳、跑步和总成绩有显著提高，但队列年龄和年龄变化之间的相互作用显示，跑步项目纵向成绩下降开始的队列年龄（35 - 39岁）比游泳项目（50 - 55岁）更小，但自行车项目的相互作用不显著。这些相互作用增加了我们对铁人三项成绩队列差异和年龄变化的认识。
研究结果的实际应用表明，省力策略可能解释了较高队列年龄组自行车成绩纵向变化缺失的原因。作者推断，在自行车项目上增加努力可能会使老年铁人三项运动员的总成绩受益。
