Using anti-bacterial mouthwash could reduce the benefits of exercise, a study has found.

Physical exertion is known to lower blood pressure but the effects are significantly reduced when people use mouthwash instead of water.

A team of international scientists said the results showed the importance of oral bacteria in cardiovascular health.

They are urging health professionals to pay attention to the oral environment when recommending interventions involving physical activity for high blood pressure.

The study was led by the University of Plymouth in collaboration with the Centre of Genomic Regulation in Barcelona.

Researchers asked 23 healthy adults to run on a treadmill for 30 minutes on two separate occasions, after which they were monitored for two hours.

At one, 30, 60 and 90 minutes after exercise they were asked to rinse their mouths with a liquid - either antibacterial mouthwash or a placebo of mint-flavoured water.

Their blood pressure was measured and saliva and blood samples were taken before exercise and at 120 minutes after exercise.

The study found that when participants rinsed with the placebo, the average reduction in systolic blood pressure was minus 5.2 mmHg at one hour after exercise.

When participants rinsed with the antibacterial mouthwash, the average systolic blood pressure was minus 2 mmHg at the same time point.