Abstract：
OBJECTIVE: Training characteristics such as duration, frequency, and intensity can be manipulated to optimize endurance performance, with an enduring interest in the role of training-intensity distribution to enhance training adaptations. Training intensity is typically separated into 3 zones, which align with the moderate-, heavy-, and severe-intensity domains. While estimates of the heavy- and severe-intensity boundary, that is, the critical speed (CS), can be derived from habitual training, determining the moderate-heavy boundary or first threshold (T1) requires testing, which can be costly and time-consuming. Therefore, the aim of this review was to examine the percentage at which T1 occurs relative to CS.
RESULTS: A systematic literature search yielded 26 studies with 527 participants, grouped by mean CS into low (11.5 km·h-1; 95% CI, 11.2-11.8), medium (13.4 km·h-1; 95% CI, 11.2-11.8), and high (16.0 km·h-1; 95% CI, 15.7-16.3) groups. Across all studies, T1 occurred at 82.3% of CS (95% CI, 81.1-83.6). In the medium- and high-CS groups, T1 occurred at a higher fraction of CS (83.2% CS, 95% CI, 81.3-85.1, and 84.2% CS, 95% CI, 82.3-86.1, respectively) relative to the low-CS group (80.6% CS, 95% CI, 78.0-83.2).
CONCLUSIONS: The study highlights some uncertainty in the fraction of T1 relative to CS, influenced by inconsistent approaches in determining both boundaries. However, our findings serve as a foundation for remote analysis and prescription of exercise intensity, although testing is recommended for more precise applications.
RESULTS: A systematic literature search yielded 26 studies with 527 participants, grouped by mean CS into low (11.5 km·h-1; 95% CI, 11.2-11.8), medium (13.4 km·h-1; 95% CI, 11.2-11.8), and high (16.0 km·h-1; 95% CI, 15.7-16.3) groups. Across all studies, T1 occurred at 82.3% of CS (95% CI, 81.1-83.6). In the medium- and high-CS groups, T1 occurred at a higher fraction of CS (83.2% CS, 95% CI, 81.3-85.1, and 84.2% CS, 95% CI, 82.3-86.1, respectively) relative to the low-CS group (80.6% CS, 95% CI, 78.0-83.2).
CONCLUSIONS: The study highlights some uncertainty in the fraction of T1 relative to CS, influenced by inconsistent approaches in determining both boundaries. However, our findings serve as a foundation for remote analysis and prescription of exercise intensity, although testing is recommended for more precise applications.
摘要：
目标：训练特征，如持续时间，频率,和强度可以被操纵以优化耐力性能，对训练强度分布在增强训练适应性方面的作用有着持久的兴趣。训练强度通常分为3个区域，与中庸一致-，沉重-，和严重强度域。虽然对高强度和高强度边界的估计，也就是说,临界速度(CS)，可以从习惯性训练中获得，确定中重边界或第一阈值(T1)需要测试，这可能是昂贵且耗时的。因此,本综述的目的是研究T1相对于CS发生的百分比.
结果：系统的文献检索产生了26项研究，527名参与者，按平均CS分为低(11.5km·h-1；95%CI，11.2-11.8)，中等（13.4km·h-1；95%CI，11.2-11.8），高（16.0km·h-1；95%CI，15.7-16.3）组。在所有研究中，T1发生在CS的82.3%（95%CI，81.1-83.6）。在中、高CS组中，T1发生在较高的CS分数(83.2%CS，95%CI，81.3-85.1和84.2%CS，95%CI，分别为82.3-86.1）相对于低CS组（80.6%CS，95%CI，78.0-83.2）。
结论：该研究强调了T1相对于CS的部分的一些不确定性，受确定两个边界的不一致方法的影响。然而,我们的发现为远程分析和规定运动强度奠定了基础，虽然测试建议用于更精确的应用。
结果：系统的文献检索产生了26项研究，527名参与者，按平均CS分为低(11.5km·h-1；95%CI，11.2-11.8)，中等（13.4km·h-1；95%CI，11.2-11.8），高（16.0km·h-1；95%CI，15.7-16.3）组。在所有研究中，T1发生在CS的82.3%（95%CI，81.1-83.6）。在中、高CS组中，T1发生在较高的CS分数(83.2%CS，95%CI，81.3-85.1和84.2%CS，95%CI，分别为82.3-86.1）相对于低CS组（80.6%CS，95%CI，78.0-83.2）。
结论：该研究强调了T1相对于CS的部分的一些不确定性，受确定两个边界的不一致方法的影响。然而,我们的发现为远程分析和规定运动强度奠定了基础，虽然测试建议用于更精确的应用。
