Triceps skin fold, arm muscular performance and fatigue were quantified, haematocrit measured and haemoglobin, serum total protein, albumin, transferrin, zinc and copper concentrations determined in 60 patients (36 women, 24 men) before and 3-45 days after surgery. On days 3 and 9 after surgery, there was a significant (P less than 0.05) decrease in serum zinc concentrations but by 45 days concentrations had return to pre-operative values. In contrast, serum copper concentrations were significantly (P less than 0.05) elevated until day 45. Haematocrit and haemoglobin and albumin concentrations were decreased significantly (P less than 0.05) 3 and 9 days after surgery, whereas serum total protein concentrations remained significantly (P less than 0.05) lower for 45 days compared with concentrations prior to surgery.