Chronic Administration of Exogenous Lactate Increases Energy Expenditure during Exercise through Activation of Skeletal Muscle Energy Utilization Capacity in Mice

Inkwon Jang; Sunghwan Kyun; Deunsol Hwang; Taeho Kim; Kiwon Lim; Hun-Young Park; Sung-Woo Kim; Jisu Kim

doi:10.3390/metabo14040220

Chronic Administration of Exogenous Lactate Increases Energy Expenditure during Exercise through Activation of Skeletal Muscle Energy Utilization Capacity in Mice

Metabolites. 2024 Apr 13;14(4):220. doi: 10.3390/metabo14040220.

Authors

Inkwon Jang^{1

2}, Sunghwan Kyun^{1

2}, Deunsol Hwang^{1

2}, Taeho Kim^{1

2}, Kiwon Lim^{1

2

3}, Hun-Young Park^{1

2}, Sung-Woo Kim^{1

2}, Jisu Kim^{1

2}

Affiliations

¹ Laboratory of Exercise and Nutrition, Department of Sports Medicine and Science in Graduate School, Konkuk University, Seoul 05029, Republic of Korea.
² Physical Activity and Performance Institute (PAPI), Konkuk University, Seoul 05029, Republic of Korea.
³ Department of Physical Education, Konkuk University, Seoul 05029, Republic of Korea.

Abstract

We compared the effects of chronic exogenous lactate and exercise training, which influence energy substrate utilization and body composition improvements at rest and during exercise, and investigated the availability of lactate as a metabolic regulator. The mice were divided into four groups: CON (sedentary + saline), LAC (sedentary + lactate), EXE (exercise + saline), and EXLA (exercise + lactate). The total experimental period was set at 4 weeks, the training intensity was set at 60-70% VO₂max, and each exercise group was administered a solution immediately after exercise. Changes in the energy substrate utilization at rest and during exercise, the protein levels related to energy substrate utilization in skeletal muscles, and the body composition were measured. Lactate intake and exercise increased carbohydrate oxidation as a substrate during exercise, leading to an increased energy expenditure and increased protein levels of citrate synthase and malate dehydrogenase 2, key factors in the TCA(tricarboxylic acid) cycle of skeletal muscle. Exercise, but not lactate intake, induced the upregulation of the skeletal muscle glucose transport factor 4 and a reduction in body fat. Hence, chronic lactate administration, as a metabolic regulator, influenced energy substrate utilization by the skeletal muscle and increased energy expenditure during exercise through the activation of carbohydrate metabolism-related factors. Therefore, exogenous lactate holds potential as a metabolic regulator.

Keywords: body composition; chronic exogenous lactate; energy substrate utilization; exercise training; metabolic during exercise; metabolic regulator.

Abstract

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