Caffeine, performance, and metabolism during repeated Wingate exercise tests

Greer et al., 1998 | J Appl Physiol (1985) | Rct

Citation

Greer F, McLean C, Graham T E. Caffeine, performance, and metabolism during repeated Wingate exercise tests. J Appl Physiol (1985). 1998-Oct;85(4):1502-8

Abstract

Investigations examining the ergogenic and metabolic influence of caffeine during short-term high-intensity exercise are few in number and have produced inconsistent results. This study examined the effects of caffeine on repeated bouts of high-intensity exercise in recreationally active men. Subjects (n = 9) completed four 30-s Wingate (WG) sprints with 4 min of rest between each exercise bout on two separate occasions. One hour before exercise, either placebo (P1; dextrose) or caffeine (Caf; 6 mg/kg) capsules were ingested. Caf ingestion did not have any effect on power output (peak or average) in the first two WG tests and had a negative effect in the latter two exercise bouts. Plasma epinephrine concentration was significantly increased 60 min after Caf ingestion compared with P1; however, this treatment effect disappeared once exercise began. Caf ingestion had no significant effect on blood lactate, O2 consumption, or aerobic contribution at any time during the protocol. After the second Wingate test, plasma NH3 concentration increased significantly from the previous WG test and was significantly higher in the Caf trial compared with P1. These data demonstrate no ergogenic effect of caffeine on power output during repeated bouts of short-term, intense exercise. Furthermore, there was no indication of increased anaerobic metabolism after Caf ingestion with the exception of an increase in NH3 concentration.

Key Findings

Furthermore, there was no indication of increased anaerobic metabolism after Caf ingestion with the exception of an increase in NH3 concentration.

Outcomes Measured

Requires manual extraction

Population

Field	Value
Population	See abstract
Sample Size	9
Age Range	See abstract
Condition	See abstract

MeSH Terms

Adult
Ammonia
Bicycling
Blood Glucose
Caffeine
Double-Blind Method
Epinephrine
Exercise Test
Glycerol
Humans
Lactates
Male
Norepinephrine
Oxygen Consumption
Physical Endurance
Physical Exertion
Potassium

Evidence Classification

Level: Rct
Publication Types: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
Vertical: caffeine

Provenance

PMID: 9760347
DOI: (not available)
PMCID: Not in PMC
Verified: 2026-04-10 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-10