Running economy assessment within cardiopulmonary exercise testing for recreational runners.

Background: The aim of this study was to evaluate the influence of running economy (RE) on running performance within recreational runners of different maximal aerobic capacity, and the feasibility of RE assessment within routine cardiopulmonary exercise testing (CPET).

Methods: Sixty-eight recreational runners (m: 49, f: 19; age: 21-54) completed a graded exercise test (GXT) until exhaustion. Maximal oxygen uptake and respiratory compensation point were obtained via CPET. RE was calculated as relative oxygen uptake per covered distance (mL/kg/km) one step below respiratory compensation point (RCP). Subjects were grouped for RE via median split and categorized into one of six fitness levels (Very Poor, Poor, Fair, Good, Excellent, Superior) (ACSM 2010).

Results: Irrespective of fitness levels, recreational runners with a more energy efficient movement (RE<215.28 mL/kg/km) reached a significant (P<0.05) higher velocity at RCP (12.2 vs. 10.8 km/h). The measured VO2max values ranged between 35.2 and 66.0 ml/min/kg. Running velocity at RCP of runners within VO2max categories Good and Superior differed significantly (P<0.05) between RE groups.

Conclusions: This study provides evidence that RE influences submaximal running performance in recreational distance runners within a broad range of maximal aerobic capacity. Complementing routine CPET with RE assessment at physiological threshold intensities and ACSM based categorization seems feasible to delineate the impact of movement efficiency and aerobic fitness on performance in recreational runners.