Table 2.
Summary of strength of pairwise associations between reason to use and type of supplements used (all athletes who use supplements n = 520).
| Maintain strength | Enhance endurance | Able to train longer | Doctors' advice | |
| Creatine | .432 (< .001) | NA | .307 (< .001) | NA |
| Iron | NA | .021(.632) | NA | .259 (< .001) |
| Ginseng | NA | NA | .088a (.044) | NA |
| Whey protein | .434 (< .001) | NA | .245 (< .001) | NA |
| Caffeine | .273 (< .001) | .220 (< .001) | NA | |
| Vitamin C | NA | NA | .055 (.209) | .003 (.944) |
a expected association from anecdotal effect. Each cell displays the ϕ coefficient and the corresponding p-values in parentheses (NA = no association expected).