The purpose of this study was to determine how closely competitive swimmers complied with their coaches' prescriptions when training in squads. A training session early in the buildup phase of the season was observed for each of 24 coaches who had been randomized to two groups: an experimental, high-intensity, low-distance program (E) and a control (usual) program (C). Swim distances, rest durations, and swim durations for at least one set of prescribed repetitions (reps) were recorded for each of 47 swimmers (87 sets, 429 reps) in E and for 49 swimmers (79 sets, 402 reps) in C. The pace of each rep, expressed as percent of the swimmer's current personal best pace for the distance of the rep, represented observed intensity. There was almost perfect agreement between the prescribed and observed swim distances for the set of reps (Spearman r = 0.99 in both groups). Prescribed and observed rest intervals were also closely matched in E and C (Spearman r = 0.87 and 0.77 respectively). Four coaches in E and 10 coaches in C prescribed intensity subjectively as easy, moderate, hard, or race-pace; mean± SD observed intensities (%) for their swimmers were 79 ± 6, 81± 3, 91 ± 2, and 93 ± 5, respectively. The relationship between these coaches' subjective training prescription and individual swimmers' interpretations of these intensities was poor (Cohen's κ = 0.39). Nine coaches in E prescribed intensity as percent of personal best pace. Although the mean prescribed and observed intensities for their swimmers were similar (89 ± 4 and 90 ± 7, respectively), the relationship between individual values was poor (Pearson r = 0.30). We conclude that swimmers complied with prescribed distances and rest intervals but were less effective in judging the intensity of swim training. We recommend that coaches monitor training intensity more closely.