Previous literature has shown that there is a positive relationship between cohesion and performance in team-based sports. The reported research extends this relationship in two ways. First the relationship between cohesion and performance was investigated in training groups of two individually-oriented sports (running and cycling). Second, individual performance in a group, with reference to cohesion, was compared to individual performance alone. Two independent studies assessed the relationship between task and social cohesion, as measured by the Group Environment Questionnaire, and performance. Study One related cohesion to athletic performance of 132 runners in a half-marathon running race. Study Two examined the relationship between cohesion and training effectiveness, as measured by recorded heart rate, amongst 17 road cyclists. These studies found that (a) social cohesion was not significantly related to performance; (b) task cohesion was positively correlated to performance, but only in Study Two; and (c) individual training is associated with significantly higher athletic performance than training in groups with low task cohesion, but is no better than training in a high task cohesion group. These results are discussed with reference to previous cohesion and exercise physiology literature, leading to conclusions being made at both a theoretical and an applied level.