Table_1_Does Becoming Fit Mean Feeling (f)it? A Comparison of Physiological and Experiential Fitness Data From the iReAct Study.DOCX

Regular exercise fosters fitness-enhancing benefits. We assume that exercise interventions become successful and sustainable if physiological benefits of exercise are also subjectively perceivable. The goal of this study was to examine how young inactive adults physiologically respond to an exercise intervention and how those responses are subjectively experienced. Furthermore, we aimed to assess whether the sequence of two distinct endurance-based exercise modes has an impact on physiological and subjectively experienced physical fitness. Thirty-one young inactive adults were assessed for this substudy of the larger iReAct study. Participants were randomly assigned to a high-intensity interval training (HIIT) or a moderate-intensity continuous training (MICT) group for 6 weeks and subsequently switched groups for a second training period. Physiological fitness data was collected at baseline, follow-up I, and follow-up II using a graded cardiopulmonary exercise test. Subjectively reconstructed (i.e., retrospective constructions) experiences relating to physical fitness were assessed at follow-up II using a biographical mapping method. A repeated-measures one-way ANOVA on each training group was performed to see whether physiological and subjectively experienced fitness differed across training periods. The rate of change between all variables was calculated for the first and the second training period in order to compare the agreement between physiological and subjective fitness improvements. Participants increased their fitness across the intervention period both physiologically and subjectively. However, the rate of change depended on the sequence of the two training modes. While VO2max increased significantly in both training periods in the MICT-HIIT sequence, a significant increase in VO2max in the HIIT-MICT sequence was only observed in the HIIT period. Participants similarly perceived those increases subjectively in their exercise-related physical fitness, although they experienced a significant decrease in the second period of the HIIT-MICT sequence. For subjectively perceived physical fitness relating to everyday activities, significant increases were only observed for the first period of the MICT-HIIT sequence. Young inactive adults can improve both their physiological and their subjectively perceived fitness through regular exercise. However, exercise modes and their sequence can make a substantial difference regarding measured and perceived physical fitness. Additionally, despite a favorable tendency toward HIIT over MICT, inter- and intra-individual variability, particularly in the subjective experiences of fitness, reiterates the necessity of individualized approaches to exercise.

规律性的锻炼能够促进健身益处的提升。本研究所假设，若锻炼的生理效益亦能被主观感知，则锻炼干预措施将更为成功且可持续。本研究旨在探讨年轻不活跃成年人如何从锻炼干预中在生理层面作出反应，以及这些反应在主观层面的体验。此外，我们旨在评估两种不同耐力型锻炼模式的顺序是否对生理和主观体验的体能产生显著影响。在更大规模的 iReAct 研究的子研究中，对31名年轻不活跃成年人进行了评估。参与者被随机分配至高强度间歇训练（HIIT）或中等强度持续训练（MICT）组，为期6周，随后在第二个训练周期中交换组别。在基线、随访I和随访II阶段，使用分级心肺运动测试收集生理体能数据。在随访II阶段，采用传记性映射方法评估与体能相关的主体重构（即，回顾性构建）的体验。对每个训练组进行了重复测量的单因素方差分析，以观察生理和主观体验的体能是否在不同训练周期中存在差异。计算了第一和第二个训练周期中所有变量变化率，以比较生理和主观体能改善之间的一致性。在干预期间，参与者在生理和主观层面均提高了他们的体能。然而，变化率取决于两种训练模式的顺序。在MICT-HIIT序列中，两个训练周期均观察到最大摄氧量（VO2max）显著增加，而在HIIT-MICT序列中，仅在HIIT周期观察到最大摄氧量显著增加。参与者同样在锻炼相关的体能提升上主观感受到了这些增加，尽管在HIIT-MICT序列的第二周期中，他们经历了显著下降。对于与日常活动相关的主体感知体能，仅在MICT-HIIT序列的第一周期观察到显著增加。年轻不活跃成年人可以通过规律性锻炼提高他们的生理和主体感知体能。然而，锻炼模式和它们的顺序在测量和感知体能方面可以产生重大差异。此外，尽管有偏向于HIIT而非MICT的积极趋势，个体间和个体内差异，尤其是在主观体验方面，再次强调了针对锻炼个体化方法的必要性。