Evidence Hub

Acute effect of metformin on exercise capacity in active males

Johnson ST, Robert C, Bell GJ, Bell RC, Lewanczuk RZ, Boulé NG

Diabetes, obesity & metabolism, 2008

Abstract

AIM: Physical activity and metformin are often used concomitantly in the treatment of diabetes, even though little is known about possible interactions between these treatment modalities. This study was designed to examine the acute effect of metformin on oxygen consumption and lactate concentration during exercise.

METHODS: Eleven healthy, active men [mean +/- s.d.: age = 29.9 +/- 3.7 years; body mass index = 25.2 +/- 2.8 kg/m2; maximal oxygen consumption (VO2max) = 53.5 +/- 8.9 ml/kg/min] completed a randomized, double-blind, placebo-controlled, crossover study. The testing protocol consisted of a standardized breakfast with metformin (1000 mg) or placebo. Three hours after breakfast, participants underwent a graded maximal exercise test on a cycle ergometer. Approximately 30 min after this exercise test, participants cycled continuously at an intensity below their ventilatory threshold for 45 min (mean exercise intensity = 69 +/- 5.5% of VO2max).

RESULTS: During the graded exercise test, average oxygen consumption was higher for the metformin condition (2.9 vs. 2.8 l/min, p = 0.04); however, there was no treatment effect on VO2max or ventilatory threshold. During continuous exercise, lactate was lower for the metformin condition (4.7 vs. 5.4 mmol/l, p = 0.05). Following a standardized lunch, glucose concentrations were lower in the metformin compared with the placebo condition (5.8 vs. 6.4 mmol/l, p = 0.04).

CONCLUSION: A single dose of metformin does not acutely…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free