A proposed test to determine physical working capacity at pain intensity threshold (PWCPIT).

Purpose: This study aimed to establish a new threshold parameter called the physical working capacity at pain intensity threshold (PWC_PIT) using a pain intensity scale and mathematical methods similar to those used to develop the physical working capacity at oxygen consumption threshold (PWC_VO2) and physical working capacity at heart rate threshold (PWC_HRT). The study had two objectives: (i) to examine the relationship between PWC_PIT and traditional PWC measures and (ii) to explore the physiological mechanisms underlying the relationship between pain perception and capacity thresholds.

Methods: Fourteen male volunteers (age 21 ± 2 years, height 176 ± 6 cm, weight 76 ± 9 kg, VO_2peak 37.8 ± 7.8 ml/kg/min^-1) underwent an incremental exhaustion test and four 8-min randomly ordered work bouts on different days at 70-100% peak power output (119-320 W) to establish their PWC_PIT, PWC_HRT and PWC_VO2. One-way repeated-measures ANOVA with Bonferroni post hoc tests and a zero-order correlation matrix were used to analyze these thresholds.

Results: PWC_PIT significantly correlated with PWC_HRT (r = 0.88, P < 0.001), PWC_VO2 (r = 0.84, P < 0.001), and gas exchange threshold (GET) (r = 0.7, P = 0.006).

Conclusion: The model for estimating PWC_HRT and PWC_VO2 can be applied to determine the PWC_PIT. By examining how PWC_PIT aligns with, differs from, or complements existing PWC threshold measures, researchers may provide a more comprehensive understanding of the factors that govern endurance performance.