Horses were allowed to beome gross before they went into training. Training-grooms got the weight off by purges, given as often as twice a week; by four-mile 'spins' in heavy clothes; and by sweats in the stable. Each box had a stove, and the horse, laden with rugs, was given a 'sauna'. As soon as the sweat was removed by scraping, whisping, and rubbing, the horse was rugged and hooded again. Thie regime, illustrated 1823, was still normal in 1840; it gave way to more moderate methods rather suddenly about 1845. The History of Horse Racing by Roger Longrigg, page 152.