In 28 male Caucasian nonprofessional ultracyclists, we investigated whether anthropometry or training volume had an influence on race speed in the 600 km at the Swiss Cycling Marathon 2007. Anthropometric parameters (age, body mass, body height, skinfold thicknesses) were determined before the race to calculate body mass index and percent body fat. In addition, participants, using a training diary, recorded their training volume in hours and kilometers in the 3 months before the race. The influence of anthropometry and training volume on speed in the race as the dependent variable was investigated in a multiple linear regression model. Anthropometry showed a moderate association with speed in the race (r[superscript 2] = 0.178, p less than 0.05), whereas training volume showed no association (r[superscript 2] = 0.000, p greater than 0.05). We concluded that anthropometry had a greater influence on race performance than training volume in recreational ultraendurance cyclists. (Contains 3 tables and 3 figures.)