The effect of an herbal dietary supplement containing ephedrine and caffeine on oxygen consumption in humans.

What Was Tested

Researchers studied Caffeine and Ephedrine in this randomized controlled trial publication.

Who Took Part

PubMed tags the participants as women only.

Measurement of peak oxygen consumption in response to the supplement followed by a double-blind placebo-controlled crossover measurement of oxygen consumption in response to the supplement.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

Because people in this Caffeine study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Neither the participants nor the staff measuring them knew who was on Caffeine, so expectations could not easily colour the readings.

Some participants received a placebo instead of Caffeine, giving a reference point.

Each person switched between Caffeine and the comparison at some point, usually with a gap in between.

The study was conducted in an academic research clinic.

Ten obese females (aged 41 +/- 4 years [body mass index (BMI)] 33.3 +/- 2.6 kg/m2) participated in the peak oxygen consumption test; six of these females participated in the crossover trial.

What Was Measured

PubMed files the paper under topics including Caffeine, Dietary Supplements, Ephedrine, Obesity, Oxygen Consumption, Plant Extracts and Weight Loss.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Caffeine and Ephedrine.

Results are reported in around 5 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2000 (Journal of alternative and complementary medicine (New York, N.Y.)), a journal based in United States.

More context: all human trials.