The effects of a caffeine containing pre-workout supplement on β2-adrenergic and MAPK signaling during resistance exercise.

What Was Tested

The paper reports a study of Copper (Supplement), published as a randomized controlled trial.

The acute myocellular responses of caffeine supplementation during resistance exercise (RE) have not been investigated. β2-Adrenergic receptors (β2AR) may be a target of the stimulatory effects of caffeine and stimulate bioenergetic pathways including protein kinase A (PKA), and mitogen-activated protein kinases (MAPK).

Elucidate the effects of pre-workout supplementation on signaling responses to an acute RE bout.

Who Took Part

By PubMed's age tags, the people studied were young adults and adults, men only.

In a randomized, counter-balanced, double-blind, placebo-controlled, within-subject crossover study, ten resistance-trained males (mean ± SD; age = 22 ± 2.4 years, height = 175 ± 7 cm, body mass = 84.1 ± 11.8 kg) consumed a caffeine containing multi-ingredient pre-workout supplement (SUPP) or color and flavor matched placebo (PL) 60 min prior to an acute RE bout of barbell back squats.

Epinephrine was determined prior to supplementation (baseline; BL), after supplementation but prior to RE (PRE), and immediately after RE (POST).

How the Study Was Run

The researchers set it up as a randomized, double-blind, placebo-controlled and crossover study.

The participants were allocated by chance, so the Copper (Supplement) group and the comparison group should start out alike.

Blinding on both sides kept the participants and researchers unaware of who received Copper (Supplement).

A placebo (an inactive look-alike) gave the Copper (Supplement) group a baseline to be compared against.

In the crossover set-up each of the participants took both Copper (Supplement) and the comparison in turn, acting as their own control.

Pre- and post-exercise muscle biopsies were analyzed for the phosphorylation (p-) of β2AR, PKA, and MAPK (ERK, JNK, p38).

What Was Measured

Topics PubMed links to this paper include Caffeine, Physical Endurance, Mitogen-Activated Protein Kinases, Adrenergic Agents, Resistance Training, Dietary Supplements and Epinephrine.

The authors tagged it with the keywords Cell signaling, Endocrine, Ergogenic aid, Muscle and Performance.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Copper (Supplement).

The abstract goes on to report its results in about 4 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2023 (European journal of applied physiology), a journal based in Germany.

More context: the Copper (Supplement) compound page, all human trials.