Author(s): RANIERI, L., DEL COSO, J., TRUJILLO-COLMENA, D., RODRÍGUEZ-CASTAÑO, A., GARCÍA-ORTIZ, C., FERNÁNDEZ-SÁNCHEZ, J., SOLANO, V., JIMÉNEZ, A., CASADO, A., Institution: UNIVERSIDAD REY JUAN CARLOS - CAMPUS DE FUENLABRADA, Country: SPAIN, Abstract-ID: 2339

INTRODUCTION:
Endurance running over prolonged periods is a biological trait of the genus Homo [1]. Approximately 620 million people worldwide run for health, recreation, or competition. This growing participation has driven sustained sports science interest in optimizing training strategies to enhance performance in recreational runners. However, key training characteristics such as training volume, methods, intensity distribution (TID), and periodization have not been systematically synthesized across existing studies. Therefore, this review aimed to synthesize current evidence on key components of endurance running training and identify the most effective training strategies for enhancing performance in recreational distance runners.
METHODS:
A systematic review was conducted according to PRISMA guidelines using PubMed, Web of Science, and Scopus. Experimental studies were included if they involved recreational distance runners (Performance Level [PL] < 3; De Pauw scale 1–5 [2]) undergoing structured training interventions with physiological assessments. Data were extracted for four TID models: polarized (POL), threshold, pyramidal, and high-intensity interval training (HIIT). A meta-analysis was performed using mean differences (MD) with 95% confidence intervals (CI) and a fixed-effect model to compare pre- and post-training outcomes across TID models.
RESULTS:
Eleven studies (360 participants) were included with a mean value of maximum oxygen uptake (V̇O2max) of 55.1±7.7 ml/kg/min, with a PL of 2.4±0.5. Average training volume was 4.5±2 h/wk, corresponding to 38±14 km/wk across 3–6 weekly sessions. The studies included various training methods comprised low-intensity continuous runs (30–90 min), tempo runs (8–50 min), and HIIT protocols including 4–12 short (40 s–1 min) or long (1–8 min) intervals with 20 s–4 min recovery. Significant improvements in V̇O2max were observed following HIIT (Z=2.3; 95% CI:0.47-5.77; p=.02), POL (Z=5.27; 95% CI: 2.47-5.39; p<.001), and threshold TID (Z=2.3; 95% CI: 0.34-4.31; p=.02). No differences were found between improvements induced by POL and HIIT models (p=0.54, Z=0.61, 95% CI: -1.82-3.46). Performance improved in time trials over 2 km (1 study), 5 km (4 studies), and 10 km (1 study), as well as in maximal treadmill speed (3 studies), speed at 8 mmol/L, and time to exhaustion. Moreover, low-volume training (2.2±0.8 h/wk) produced V̇O2max improvements comparable to higher volumes (5.5±0.9 h/wk).
CONCLUSION:
Recreational distance runners can improve performance and V̇O2max using different TID models, with HIIT and POL approaches consistently enhancing V̇O2max without clear superiority. Comparable V̇O2max gains occur with both low- and high-volume training. As a practical application, weekly training should prioritize low-intensity continuous running (~70–80% of total volume), target approximately 50 km per week, and integrate threshold and HIIT sessions within a structured periodization framework. [1] Bramble and Lieberman, 2004. [2] De Pauw, 2013.