Caffeine augments the lactate and interleukin-6 response to moderate-intensity exercise in males but not females
Date
2022
Authors
Abbotts, Kieran Shay Struebin, author
Bell, Christopher, advisor
Hamilton, Karyn, committee member
Melby, Christopher, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
The release of interleukin (IL)-6 from contracting skeletal muscle is thought to contribute to some of the health benefits bestowed by exercise. This IL-6 response appears proportional to exercise volume. Unfortunately, high volumes of exercise are not feasible for all people. Caffeine augments the magnitude of increase in circulating concentration of IL-6 in response to high-intensity and long-duration exercise, in males. Caffeine is also known to increase circulating concentrations of lactate during exercise. One of the mechanisms thought to contribute to IL-6 release from exercising skeletal muscle is lactate production. We hypothesized that caffeine, ingested prior to moderate-intensity exercise, would lead to greater circulating concentrations of lactate and IL-6 in a study population comprising both males and females. 15 healthy adults (9 males and 6 females, aged 26±7 years, (mean ± SD)) completed 30-minutes of moderate-intensity cycle ergometer exercise, equivalent to the ventilatory threshold, after ingesting either caffeine (6 mg/kg) or placebo. Arterialized-venous blood was collected throughout each of the exercise sessions. Compared with placebo, caffeine increased end-exercise circulating concentrations of lactate (5.72±3.95 vs. 7.14±4.66 mmol/L, P<0.001) but not end-exercise IL-6 (1.84±0.97 vs. 2.37±1.04 pg/mL, P=0.139). However, when females were excluded from the analysis, caffeine augmented (P=0.04) the magnitude of increase of end-exercise IL-6 concentration (1.80±0.86 vs. 2.57±1.21 pg/mL); this effect was further exaggerated after 30-minutes of inactive recovery (3.81±2.32 vs. 5.06±3.22 pg/mL). Noteworthy, caffeine evoked greater end-exercise lactate concentrations in data sets containing only males (P=0.02) and only females (P=0.002) but did not influence the IL-6 response in females (P=0.94). Our preliminary data imply that in males unable/unwilling to perform high-intensity and/or long-duration exercise, caffeine may potentially enhance the IL-6 mediated health benefits of relatively short, moderate-intensity exercise.
Description
Rights Access
Subject
IL-6
physical activity
cycling
skeletal muscle
myokines