The effects of vitamin C supplementation on symptoms of delayed onset muscle soreness.

AIM: The aim of this study was to compare the effects of 8 days of vitamin C (VC) supplementation on elbow flexor delayed onset muscle soreness (DOMS) to 8 days of placebo ingestion. METHODS: For 3 days prior to an exercise bout (2 x 20 eccentric elbow extensions), and for 5 days after, a treatment group ingested 3 x 1000 mg/day of VC versus 3 x 50 mg/day of glucose ingestion for the placebo group over the same time period. All subjects were prescreened via dietary recall to exclude any subjects with habitual VC consumption greater than 400 mg/day. Subject comprised 24 subjects (male and female) randomly divided into 2 groups of 12 subjects. Treatment group comprised 5 females and placebo group comprised 8 females. RESULTS: Data from a repeated measures ANOVA indicate that DOMS was successfully induced in both groups via significant time effects for strength loss (P = 0.0001), point tenderness (P = 0.0001), elbow flexor decreased range of motion (P = 0.013), and subjective pain (P = 0.0001). However, there were no significant between group differences in response to any of the aforementioned variables: strength loss (P = 0.202), point tenderness (P = 0.824), elbow flexor range of motion (P = 0.208), subjective pain (P = 0.342). CONCLUSIONS: The results of this study suggest that a VC supplementation protocol of 3 x 1000 mg/day for 8 days is ineffective in protecting against selected markers of DOMS.

Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage.

BACKGROUND: Numerous antioxidant and anti-inflammatory agents have been identified in tart cherries. OBJECTIVE: To test the efficacy of a tart cherry juice blend in preventing the symptoms of exercise induced muscle damage. METHODS: This was a randomised, placebo controlled, crossover design. Fourteen male college students drank 12 fl oz of a cherry juice blend or a placebo twice a day for eight consecutive days. A bout of eccentric elbow flexion contractions (2 x 20 maximum contractions) was performed on the fourth day of supplementation. Isometric elbow flexion strength, pain, muscle tenderness, and relaxed elbow angle were recorded before and for four days after the eccentric exercise. The protocol was repeated two weeks later with subjects who took the placebo initially, now taking the cherry juice (and vice versa). The opposite arm performed the eccentric exercise for the second bout to avoid the repeated bout protective effect. RESULTS: Strength loss and pain were significantly less in the cherry juice trial versus placebo (time by treatment: strength p<0.0001, pain p = 0.017). Relaxed elbow angle (time by treatment p = 0.85) and muscle tenderness (time by treatment p = 0.81) were not different between trials. CONCLUSIONS: These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise was 22% with the placebo but only 4% with the cherry juice.

Risk factors for lower extremity injury: a review of the literature.

Prospective studies on risk factors for lower extremity injury are reviewed. Many intrinsic and extrinsic risk factors have been implicated; however, there is little agreement with respect to the findings. Future prospective studies are needed using sufficient sample sizes of males and females, including collection of exposure data, and using established methods for identifying and classifying injury severity to conclusively determine additional risk factors for lower extremity injury.

Changes in selected fitness parameters following six weeks of snowshoe training.

BACKGROUND: Recently, there has been an increase in popularity and participation in the sport of snowshoeing. While the sport has gained considerable recognition, to date there is little or no scientific research regarding training responses to snowshoeing as a form of exercise. Therefore, the purpose of this study was to determine whether snowshoe training could improve fitness measures. A further purpose was to compare responses from a snowshoe training program to a similarly designed run training program. METHODS: This prospective, comparative study was conducted with healthy males and females between the ages of 19 and 24. These subjects were recruited from the University of Vermont population and surrounding community. Following baseline measurements in VO2max, running time to exhaustion (RTE), and anthropometry, 17 subjects (10 snowshoers and 7 runners) participated in a six week conditioning program. Both groups exercised for 30 min at 75-85% age predicted maximum heart rate, 3-4 times per week, for a total of 18 sessions. RESULTS: VO2max improved significantly in both running and snowshoeing groups, 6.3 and 8.5%, respectively. Run time to exhaustion also improved significantly in both groups, 23.3 and 33.5%, respectively. There were no changes in anthropometry for either group. With the exception of RTE, there were no statistically significant differences between groups in any other measurements at baseline. CONCLUSIONS: These results support the acceptability of snowshoeing as a valid means to improve or maintain cardiovascular endurance.