Comedy fans who have already given up on their new year's resolution to keep fit can tone up by watching some of their favourite shows, British research claims.

Intense laughter can help people burn as many as 120 calories an hour, the research suggests.

Chuckling at sitcoms could give viewers' muscles a workout, Dr Helen Pilcher of the Comedy Research Project claimed.

Different intensities of laughter give a range of results, the report compiled by Dr Pilcher alongside Timandra Harkness for British television channel Dave, showed.

While sniggering can burn up to 10 calories per hour, the so-called howler - described by the researchers as "flat out, uncontrollable, roll on the floor laughter" - is said to burn up to 120 calories an hour.

"This report raises the joyous possibility that watching comedy shows can help you to shape your six pack by targeting internal oblique muscles more effectively than sit-ups," Dr Pilcher said.

"I definitely felt more toned after watching hours of TV comedies."