TY - JOUR
T1 - The Relationship Between the Moderate–Heavy Boundary and Critical Speed in Running
AU - Hunter, Ben
AU - Meyler, Samuel
AU - Maunder, Ed
AU - Cox, Tobias H
AU - Muniz, Daniel
N1 - © 2024 Human Kinetics, Inc. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1123/ijspp.2024-0101
PY - 2024/7/24
Y1 - 2024/7/24
N2 - Purpose: 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.
AB - Purpose: 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.
KW - endurance training
KW - exercise prescription
KW - intensity domains
KW - monitoring
KW - testing
UR - http://www.scopus.com/inward/record.url?scp=85201259938&partnerID=8YFLogxK
U2 - 10.1123/ijspp.2024-0101
DO - 10.1123/ijspp.2024-0101
M3 - Review article
SN - 1555-0265
VL - 19
SP - 963
EP - 972
JO - International Journal of Sports Physiology and Performance (IJSPP)
JF - International Journal of Sports Physiology and Performance (IJSPP)
IS - 9
ER -