Unadjusted means (SD) of athlete reported outcomes
| ω | Intervention group | Control group | |||
| M (SD) | N | M (SD) | N | ||
| Doping willingness (T0) | 0.92 | 1.56 (0.99) | 453 | 1.66 (1.10) | 461 |
| Doping willingness (T1) | 0.94 | 1.49 (0.85) | 340 | 1.61 (1.01) | 342 |
| Doping willingness (T2) | 0.92 | 1.42 (0.71) | 305 | 1.57 (0.93) | 223 |
| Doping moral disengagement (T0) | 0.76 | 1.56 (0.77) | 453 | 1.66 (0.85) | 461 |
| Doping moral disengagement (T1) | 0.82 | 1.53 (0.83) | 340 | 1.64 (0.87) | 342 |
| Doping moral disengagement (T2) | 0.84 | 1.53 (0.69) | 305 | 1.57 (0.81) | 222 |
| Doping attitudes (T0) | 0.88 | 1.49 (0.74) | 451 | 1.62 (0.82) | 461 |
| Doping attitudes (T1) | 0.90 | 1.46 (0.75) | 340 | 1.57 (0.91) | 342 |
| Doping attitudes (T2) | 0.90 | 1.46 (0.73) | 304 | 1.55 (0.90) | 223 |
| Doping efficacy (T0) | 0.97 | 5.82 (1.83) | 448 | 5.29 (2.08) | 460 |
| Doping efficacy (T1) | 0.98 | 5.74 (1.94) | 340 | 5.46 (2.05) | 342 |
| Doping efficacy (T2) | 0.99 | 5.79 (1.91) | 303 | 5.41 (2.11) | 223 |
| Behaviours against inadvertent doping (T0) | 0.71 | 0.52 (1.16) | 454 | 0.47 (0.99) | 459 |
| Behaviours against inadvertent doping (T1) | 0.73 | 0.64 (1.16) | 341 | 0.69 (1.28) | 340 |
| Behaviours against inadvertent doping (T2) | 0.78 | 0.58 (1.10) | 305 | 0.74 (1.30) | 222 |
| Antidoping knowledge (T0) | – | 2.53 (1.56) | 452 | 2.51 (1.42) | 459 |
| Antidoping knowledge (T1) | – | 2.73 (1.53) | 341 | 2.56 (1.49) | 340 |
| Antidoping knowledge (T2) | – | 3.03 (1.49) | 305 | 2.59 (1.58) | 221 |
| Perceived coach need support (T0) | 0.89 | 5.83 (0.78) | 452 | 5.72 (0.82) | 462 |
| Perceived coach need support (T1) | 0.93 | 5.79 (0.88) | 339 | 5.68 (0.84) | 342 |
| Perceived coach need support (T2) | 0.91 | 5.93 (0.82) | 304 | 5.87 (0.83) | 222 |
| Perceived coach need thwarting (T0) | 0.84 | 2.34 (0.88) | 452 | 2.40 (0.93) | 462 |
| Perceived coach need thwarting (T1) | 0.86 | 2.22 (0.92) | 339 | 2.35 (0.90) | 342 |
| Perceived coach need thwarting (T2) | 0.88 | 2.08 (0.88) | 304 | 2.16 (0.92) | 222 |
| Need satisfaction (T0) | 0.91 | 5.59 (0.98) | 452 | 5.54 (0.85) | 456 |
| Need satisfaction (T1) | 0.93 | 5.64 (0.94) | 337 | 5.48 (0.90) | 339 |
| Need satisfaction (T2) | 0.94 | 5.77 (0.91) | 305 | 5.62 (0.97) | 217 |
| Need frustration (T0) | 0.93 | 2.41 (1.19) | 452 | 2.51 (1.20) | 455 |
| Need frustration (T1) | 0.93 | 2.13 (0.97) | 337 | 2.39 (1.13) | 338 |
| Need frustration (T2) | 0.93 | 2.13 (1.04) | 305 | 2.32 (1.30) | 217 |
| Yes (%) | N | Yes (%) | N | ||
| Prohibited use (T0)* | – | 40 (8.8%) | 452 | 34 (7.4%) | 460 |
| Prohibited use (T1) | – | 27 (5.9%) | 341 | 13 (2.8%) | 342 |
| Prohibited use (T2) | – | 25 (5.5%) | 304 | 13 (2.8%) | 223 |
*We measured athlete reports (yes/no) of prohibited substance use in the past 12 months (at baseline) or since the previous survey completion (at postintervention and follow-up), but did not analyse these data because, as stated in our protocol, given that only a small percentage of athletes admit using such substances, we did not expect to have power to detect change in this variable.
ω, omega reliability coefficient; T0, Baseline; T1, 3 months (end of intervention); T2, 5 months from baseline.