Training Intensity Distribution, Load Management, and Performance in Recreational Long-Distance Runners

Purpose: Recreational runners represent a growing population in endurance sports, yet limited data are available on their training characteristics and how these relate to performance. This study aimed to describe the training intensity distribution, internal training load, and their associations with performance outcomes in recreational runners preparing for a marathon or halfmarathon. Methods: A total of 48 recreational runners (22 marathoners, 26 half-marathoners) were monitored over a 12-week training period prior to their respective races. Training sessions were recorded using GPS and heart rate monitors, and volumes were categorized into 3 intensity zones (Z1, Z2, Z3). Internal load was calculated using individualized training impulse (Edwards' training impulse [eTRIMP]). Weekly training load, session average load, and time-normalized internal load (eTRIMP per minute [eTRIMP/min]) were computed. Pearson correlations were used to assess relationships with performance. Results: Both groups adopted a pyramidal training intensity distribution. When considering the full sample, most training was performed in Z1(69.1% [8.5%]), followed by Z2 (17.3% [5.2%]) and Z3 (13.6% [5.3%]). No significant differences were observed between marathon and half-marathon groups in weekly eTRIMP (911 [210] a.u.) or session load. Among marathoners, performance was significantly correlated with Z2 volume (r = -.6), Z2 percentage (r = -.5), and eTRIMP/min (r = -.6). Similar associations were found in halfintensity distribution irrespective of race distance. Moderate-intensity training and higher time-normalized internal load are key factors associated with endurance performance, offering practical insights for structuring training plans.