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Recent studies suggest that a substantial proportion of athletes with spinal cord injury have insufficient 25(OH) vitamin D (25(OH)D) status, which may be associated with decreased muscle strength. This study consisted of two parts: (a) to examine the effects of a 12- to 16-week vitamin D 3 supplementation protocol on 25(OH)D concentration and (b) to determine whether subsequent 25(OH)D status impacts muscle performance in elite athletes with spinal cord injury. Thirty-four members (age: 33 ± 15 years, weight: 69.6 ± 28.2 kg, and height: 170.2 ± 25.4 cm) of the U.S. and Canadian Paralympic program participated in the study. 25(OH)D concentrations and performance measures (handgrip strength and 20-m wheelchair sprint) were assessed pre- and postsupplementation. Participants were assigned a vitamin D 3 supplementation protocol based on initial 25(OH)D concentrations. Participants with deficient 25(OH)D status (<50 nmol/L) received 50,000 IU/week for 8 weeks, and participants with insufficient status (50-75 nmol/L) received 35,000 IU/week for 4 weeks, after which both received a maintenance dose of 15,000 IU/week. Participants with sufficient status (>75 nmol/L) received the maintenance dose of 15,000 IU/week. 25(OH)D concentrations increased significantly (p < .001; 66.3 ± 24.3 nmol/L and 111.3 ± 30.8 nmol/L pre- and postsupplementation, respectively). About 26% of athletes had sufficient 25(OH)D concentrations presupplementation, and 91% had sufficient concentrations postsupplementation. About 62% of participants improved handgrip strength postsupplementation with no change in 20-m wheelchair sprint performance. The supplementation protocol was effective for achieving sufficient vitamin D concentrations in elite athletes with spinal cord injury.

Vitamin D is well known for its role in calcium regulation and bone health, but emerging literature tells of vitamin D's central role in other vital body processes, such as: signaling gene response, protein synthesis, hormone synthesis, immune response, plus, cell turnover and regeneration. The discovery of the vitamin D receptor within the muscle suggested a significant role for vitamin D in muscle tissue function. This discovery led researchers to question the impact that vitamin D deficiency could have on athletic performance and injury. With over 77% of the general population considered vitamin D insufficient, it's likely that many athletes fall into the same category. Research has suggested vitamin D to have a significant effect on muscle weakness, pain, balance, and fractures in the aging population; still, the athletic population is yet to be fully examined. There are few studies to date that have examined the relationship between vitamin D status and performance, therefore, this review will focus on the bodily roles of vitamin D, recommended 25(OH)D levels, vitamin D intake guidelines and risk factors for vitamin D insufficiency in athletes. In addition, the preliminary findings regarding vitamin D's impact on athletic performance will be examined.

Objective: To determine the effects of two water-soluble dietary fibers, ultrahigh-viscosity hydroxypropylmethylcellulose (UHV-HPMC, nonfermentable) and psyllium fiber (fermentable), on postprandial glucose and second meal effects., Methods: In a single-blind crossover design, 12 healthy adult subjects were given standardized, premeasured breakfast and lunch meals with either 4 g of the fiber supplements or a placebo. Blood glucose was measured with a continuous blood glucose monitoring system (DexCom Seven Plus, San Diego, CA)., Results: Subjects consuming UHV-HPMC had significantly (p < 0.05) lower blood glucose area under the curve (AUC) 2 hours after breakfast than those receiving a placebo. Subjects consuming psyllium also tended to have lower glucose levels than the placebo group. Peak glucose concentration following breakfast was significantly (p < 0.01) less with UHV-HPMC when compared with the placebo. No significant differences in AUC or peak glucose concentration between treatments following the second meal (lunch) were detected, suggesting no residual effect from the fiber supplements., Conclusions: Supplementation with viscous water-soluble fibers may be an effective means of reducing the glycemic response of a meal in healthy adults.

To maximize training quality, athletes have sought nutritional supplements that optimize recovery. This study compared chocolate milk (CHOC) with a carbohydrate replacement beverage (CRB) as a recovery aid after intense exercise, regarding performance and muscle damage markers in trained cyclists. Ten regional-level cyclists and triathletes (maximal oxygen uptake 55.2 ± 7.2 mL·kg-1·min-1) completed a high-intensity intermittent exercise protocol, then 15-18 h later performed a performance trial at 85% of maximal oxygen uptake to exhaustion. Participants consumed 1.0 g carbohydrate·kg-1·h-1 of a randomly assigned isocaloric beverage (CHOC or CRB) after the first high-intensity intermittent exercise session. The same protocol was repeated 1 week later with the other beverage. A 1-way repeated measures analysis of variance revealed no significant difference (p = 0.91) between trials for time to exhaustion at 85% of maximal oxygen uptake (CHOC 13 ± 10.2 min, CRB 13.5 ± 8.9 min). The change in creatine kinase (CK) was significantly (p < 0.05) greater in the CRB trial than in the CHOC trial (increase CHOC 27.9 ± 134.8 U·L-1, CRB 211.9 ± 192.5 U·L-1), with differences not significant for CK levels before the second exercise session (CHOC 394.8 ± 166.1 U·L-1, CRB 489.1 ± 264.4 U·L-1) between the 2 trials. These findings indicate no difference between CHOC and this commercial beverage as potential recovery aids for cyclists between intense workouts. [ABSTRACT FROM AUTHOR]