Normally aerobic exercise such as running or swimming, which raise the heart rate for a sustained period, is recommended to deal with higher cholesterol levels.

But the study, conducted by researchers at the Human Performance Laboratory in Norfolk, Virginia, found that pushing the body with a variety of "resistance exercises", in which the legs and arms push against a weight, was also an effective tactic.

This could mean that people who find it hard to complete aerobic exercises, such as asthmatics, have another way to reduce high cholesterol levels.

Levels down by one tenth

The researchers selected women under the age of 35 with a sedentary lifestyle, and made them complete 50 minutes of exercise three times a week.

This included leg curls, press-ups, and weight training until the muscles were exhausted.

After 14 weeks they found that on average cholesterol levels had dropped by 10 per cent, and in addition levels of the more dangerous low density cholesterol had fallen by 14 per cent, compared with a group that had not exercised.

The women did not lose weight, but converted body fat into muscle.

The research suggested that the increase in strength had contributed to the falling cholesterol levels.

High cholesterol levels are responsible for coronary artery heart disease, one of the UK's biggest killers.

Exercise is not the only way to treating high cholesterol levels - improvements in diet are also important, and drug treatments are available.

People should also stop smoking, say experts.