LOS ANGELES-  Post-menopausal women can turn back the time clock by 16 years with just 12 weeks’ of sweat on an exercise bike, a new study claims.

The research claimed that over-50s who make regular visits to the gym, go for a long bike ride or enjoy a swim can regain the fitness they had in their thirties.

Tests on older women revealed that a one-hour cycling session five days a week improved their blood pressure and heart rate, reports The Sun.

In an extra bonus, their ability to burn fat also rocketed 10 per cent.

Professor George Brooks, of the University of California, said: “The women in our study had the cardiovascular and metabolic capabilities of women 16 years younger.

“The results are very encouraging for exercise without weight loss.”