Manchester United manager Sir Alex Ferguson installed tanning booths at the club's Carrington training ground in order to give his players enough Vitamin D intake.

Manchester United manager Sir Alex Ferguson installed tanning booths at the club's Carrington training ground in order to give his players enough Vitamin D intake.

The revelation comes in a study carried out by academics at Harvard Business School in Boston into the managerial methods of Ferguson, who has been in charge of the Red Devils since 1986.

The Daily Mail quotes a section of the report, which said: "[Ferguson] could talk enthusiastically about the new Vitamin D machine (which perhaps most resembled a tanning booth) in the players' dressing room at Carrington, put there to help them counterbalance the lack of sunlight in Manchester, or his plan for the new season to give players staggered one-week breaks in the winter months to replenish their Vitamin D."

The study was carried out by Anita Elberse and Tom Dye.