The aim of this study was to investigate differences in blood lactate accumulation following 10 and 20 sec of maximal cycle ergometer exercise. Body mass, stature, and age of the group was determined prior to testing (82.57 ± 5.94 kg 177 ± 5.94 cm and 21.42 ± 1.61 yrs, respectively). Eight male rugby union players performed two maximal sprints in a random fashion of 10 and 20 sec duration on a cycle ergometer. During the 10 and 20 sec trial, blood lactate levels measured were as follows 1.58 ± 0.78, 4.43 ± 1.4, and 3.5 ± 1.2 mmol.l⁻¹ vs. 1.72 ± 0.65, 6.14 ± 2, and 5.68 ± 2.22 mmol.l⁻¹, respectively. Differences were found (P < 0.01) from rest to 5 and 10 min postexercise in both groups. Differences in concentration also were found between groups at both postexercise stages (P < 0.01). The reduction in blood lactate concentrations observed between the 5 to 10 min recovery stages were 0.91 ± 0.58 mmol.l⁻¹ vs. 0.46 ± 0.48 mmol.l⁻¹ following 10 and 20 sec of maximal exercise, respectively (P > 0.05). The concentrations observed are interesting and may influence recovery time and subsequent exercise performance.