“Increased sexual activity produces more testosterone, which leads to less depression and a better cardiovascular performance which means an improved metabolism.”

Dr Jannini said the research has been carried out by the University of Florence on 4,000 men and the study revealed that those who were unfaithful had a poor cardiovascular performance because they were “also coping with the increased stress of their infidelity.”

She added that the study had shown a poor quality sex life could also lead to depression.