Creatine kinase levels during preseason camp in National Collegiate Athletic Association Division I football athletes.

OBJECTIVE

To investigate mean creatine kinase (CK) levels in National Collegiate Athletic Association (NCAA) Division I football athletes and the relationship between mean CK levels and demographic variables.

DESIGN

Observational cohort.

SETTING

NCAA Division I football program.

PARTICIPANTS

NCAA Division I football athletes.

INTERVENTIONS

Blood and urine samples were obtained from 32 athletes on the first (time 1), third (time 2), and seventh (time 3) days of football camp.

MAIN OUTCOME MEASURES

Mean CK levels. The hypotheses were formulated before the data were collected.

RESULTS

All urine samples tested negative for blood. Mean CK levels were 284.7 U/L at time 1, 1299.8 U/L at time 2, and 1562.4 U/L at time 3. The increases in means were statistically significant (P < 0.005 for all pairwise comparisons). Most demographic variables were not related to mean CK levels. The number of days in the precamp conditioning program was negatively associated with mean CK levels (P = 0.0284).

CONCLUSIONS

Mean CK levels in NCAA Division I football athletes during camp were higher than the serological criteria for rhabdomyolysis commonly used in clinical practice. More data are needed to assess if the number of days of participation in precamp conditioning is related to lower CK levels in NCAA Division I football athletes during camp.