Forty Poland China barrows (190–240 lb.) were allotted into four lots and assigned rations which varied in level of fat and carbohydrate. After a two-week feeding period, five hogs from each lot were exercised to exhaustion immediately prior to slaughter. Hams from the exercised hogs were significantly darker in color and firmer in structure than those from the unexercised hogs regardless of ration; however, the darkest hams appeared in the low carbohydrate lot (Lot II). A low carbohydrate ration was effective in experimentally producing hams which were darker in appearance and firmer in structure than their respective controls. Conversely medium and high sucrose rations produced hams which were lighter in color and softer in structure than their controls. The rations and exercise significantly altered the color, pH, glycogen and expressible H2O values of the gluteus medius and biceps femoris but had a smaller effect on the characteristics of the rectus femoris and the pectoralis profundus.