Zinc status in male collegiate cross‐country skiers and its relationship to athletic performance

Abstract

The relationship between dietary zinc, zinc status, and athletic performance was investigated in 11 men on the University of New Hampshire cross‐country ski team through one training year. Subjects completed 3‐day diet records, anthropometric measurements, and blood draws at the end of each of the 4 training phases: Volume phase, May – Aug.; Intensity phase, Sept. – Nov.; Competition phase, Dec. – March; and Recovery phase, March – April. Performance tests were performed after the Volume, Intensity, and Recovery phases. Plasma zinc was within the normal range for all athletes at all time periods, with a mean of 14.4 μmol/L and a range of 11.1 to 17.3 μmol/L. Plasma zinc was positively correlated (r = 0.221) with dietary zinc. Plasma zinc was lower (P < 0.05) after the recovery phase than after each of the other phases, perhaps because the contribution of zinc from breakfast cereals in the recovery phase was half what it was during the other three phases. Plasma zinc was positively correlated (r = 0.463, p = 0.020) with the max number of pull ups in 1 min (a test of endurance) and negatively correlated (r = −0.410, p ≤ 0.05) with max bench press (a test of power). Though plasma zinc was in the normal range for all athletes, their performance in exercises requiring competitive motions (muscle endurance) was positively correlated with their zinc status, while their performance in exercises requiring maximal exertion (muscle power) was not.