Advanced Footwear Technology, but not Acute Ingestion of a Ketone Monoester, Improves Running Economy in Middle- and Long-Distance Runners.

Abstract

Purpose: This study examined the separate and combined effects of advanced footwear technology (AFT) and acute ingestion of a ketone monoester on running economy (RE), time-to-exhaustion (TTE), and other metabolic and cardiorespiratory parameters.

Methods: In a four-condition, placebo-controlled, randomized crossover design, 18 middle- and long-distance runners (male/female, 10/8, V̇O2peak: 59.4 ± 7.2 mL·kg-1·min-1) completed five 8 min stages of submaximal running (male: 10-14 km·h-1; female: 9-13 km·h-1) on a motorized treadmill, immediately followed by a ramp test to volitional exhaustion. Participants consumed 500 mL of either a 10% carbohydrate solution (CHO) or 500 mg·kg-1 body mass of an (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone monoester with flavored water (KME) 20 min before exercise, and an additional 300 mL of the 10% carbohydrate solution or 250 mg·kg-1 body mass of KME during exercise, while wearing either Nike Pegasus Turbo (PEG) or Nike ZoomX Vaporfly Next% 3 (VAP) running shoes. The four randomized conditions were PEG+CHO, PEG+KME, VAP + CHO, and VAP + KME.

Results: RE was significantly improved during the third and fourth submaximal running stages in VAP + CHO and VAP + KME compared to PEG+CHO and PEG+KME (all P < 0.05; ES = 0.53-0.84). RE was also improved during the fifth submaximal running stage in VAP + KME compared to PEG+CHO, and in VAP + CHO and VAP + KME compared to PEG+KME (all P < 0.05; ES = 0.56-0.66). No differences in RE were found between CHO and KME conditions. TTE was significantly longer in VAP + CHO (381 ± 125 s) than PEG+CHO (356 ± 140 s; ES = 0.18, P = 0.023) and PEG+KME (329 ± 131 s, ES = 0.40, P < 0.001) and in VAP + KME (375 ± 125 s) than PEG+KME (ES = 0.35, P < 0.001).

Conclusions: AFT, but not the acute ingestion of a ketone monoester, improved the RE of trained male and female middle- and long-distance runners at submaximal running speeds.