Risk Factors for Collegiate Swimmers Hospitalized With Exertional Rhabdomyolysis.

OBJECTIVE: To identify midseason risk factors for symptomatic exertional rhabdomyolysis (sER) in swimmers after a novel upper body workout. DESIGN: Retrospective (1) survey and (2) analyses of observational laboratory data conducted over a 16-week training period, 2 months before sER. SETTING: Midwest University. PARTICIPANTS: Thirty-four collegiate swimmers. INDEPENDENT VARIABLES: (1) Motivation, symptoms, and supplements for survey variables. (2) Changes (midseason minus preseason) in body composition, blood pressure (BP), urinary measures, and protein shake ingestion for laboratory variables. MAIN OUTCOME MEASURES: Swimmers were categorized in hospitalized (H), treated and released from hospital (RH), and nonhospitalized (NH) groups for analyses. RESULTS: (1) Six swimmers were in the H group (17.6%; 3 male/3 female) and 7 in the RH group (20.6%; 3 male/4 female). Nonsignificant trend toward H swimmers relating more upper body soreness (≥9/10) than RH (8/10) and NH (6/10) swimmers (P > 0.05) while reporting "felt bad and workout went poorly" (P = 0.009). H and RH swimmers reported more arm locking during the workout (P = 0.04) and brown urine after arm competition compared with NH-group swimmers (P = 0.03). (2) Increases in right systolic (P = 0.01) and left diastolic (P = 0.02) BP, with trends toward decreased left arm lean mass (P = 0.06) in H compared with RH and NH swimmers. Female H swimmers had more acidic urine (pH = 5.50 vs 6.9; P = 0.004), less volume, and higher specific gravity than RH + NH swimmers. All H swimmers regularly ingested protein shakes after workouts. CONCLUSIONS: Risk factors for sER included exceptional motivation, extreme soreness, increased resting BP, acidic urine (females), and regular ingestion of protein shakes.

Vitamin D supplementation and body composition changes in collegiate basketball players: a 12-week randomized control trial.

Background: Vitamin D promotes bone and muscle growth in non-athletes, suggesting supplementation may be ergogenic in athletes. Our primary aim was to determine if modest Vitamin D supplementation augments favorable body composition changes (increased bone and lean mass and decreased fat mass) and performance in collegiate basketball players following 12 weeks of standardized training. Methods: Members of a men's and women's NCAA D1 Basketball team were recruited. Volunteers were randomized to receive either a weekly 4000 IU Vitamin D3 supplement (D3) or placebo (P) over 12 weeks of standardized pre-season strength training. Pre- and post-measurements included 1) serum 25-hydroxy vitamin D (25(OH)D); 2) body composition variables (total body lean, fat, and bone mass) using dual-energy X-ray absorptiometry (DXA) scans and 3) vertical jump test to assess peak power output. Dietary intake was assessed using Food Frequency questionnaires. Main outcome measures included changes (∆: post-intervention minus pre-intervention) in 25(OH)D, body composition, and performance. Results: Eighteen of the 23 players completed the trial (8 females/10 males). Eight received the placebo (20 ± 1 years; 3 females) while ten received Vitamin D3 (20 ± 2 years; 5 females). Weekly Vitamin D3 supplementation induced non-significant increases (∆) in 25(OH)D (2.6 ± 7.2 vs. -3.5 ± 5.3 ng/mL; p = 0.06), total body bone mineral content (BMC) (73.1 ± 62.5 vs. 84.1 ± 46.5 g; p = 0.68), and total body lean mass (2803.9 ± 1655.4 vs. 4474.5 ± 11,389.8 g; p = 0.03), plus a non-significant change in body fat (-0.5 ± 0.8 vs. -1.1 ± 1.2%; p = 0.19) (Vitamin D3 vs. placebo supplementation groups, respectively). Pre 25(OH)D correlated with both Δ total fat mass (g) (r = 0.65; p = 0.003) and Δ total body fat% (r = 0.56; p = 0.02). No differences were noted in peak power output ∆ between the D3 vs. P group (-127.4 ± 335.4 vs. 50.9 ± 9 W; NS). Participants in the D3 group ingested significantly fewer total calories (-526.2 ± 583.9 vs. -10.0 ± 400 kcals; p = 0.02) than participants in the P group. Conclusions: Modest (~517 IU/day) Vitamin D3 supplementation did not enhance favorable changes in total body composition or performance, over 3 months of training, in collegiate basketball players. Weight training provides a robust training stimulus for bone and lean mass accrual, which likely predominates over isolated supplement use with adequate caloric intakes.