Thursday, November 27, 2008

Fat Intake and Injury in Female Runners


Our purpose was to determine the relationship between energy intake, energy availability, dietary fat and lower extremity injury in adult female runners. We hypothesized that runners who develop overuse running-related injuries have lower energy intakes, lower energy availability and lower fat intake compared to non-injured runners.


Eighty-six female subjects, running a minimum of 20 miles/week, completed a food frequency questionnaire and informed us about injury incidence over the next year.


Injured runners had significantly lower intakes of total fat (63 ± 20 vs. 80 ± 50 g/d) and percentage of kilocalories from fat (27 ± 5 vs. 30 ± 8 %) compared with non-injured runners. A logistic regression analysis found that fat intake was the best dietary predictor, correctly identifying 64% of future injuries. Lower energy intake and lower energy availability approached, but did not reach, a significant association with overuse injury in this study.


Fat intake is likely associated with injury risk in female runners. By documenting these associations, better strategies can be developed to reduce running injuries in women.

Bottom line: if you run, you need to eat! Female runners take heed, eat more protein and fat!

ISSN Publishes Position Statement on Nutrient Timing

The International Society of Sports Nutrition has published a position statement on nutrient timing, which is the practice of ingesting the right nutrients at the right times in relation to exercise to maximize exercise performance and the benefits resulting from exercise. The statement included eight tenets.

The second tenet reads, "During exercise, carbohydrate [CHO]should be consumed at a rate of 30 - 60 grams of CHO/hour in a 6 - 8 % CHO solution (8 - 16 fluid ounces) every 10 - 15 minutes. Adding protein [PRO] to create a CHO:PRO ratio of 3 - 4:1 may increase endurance performance and maximally promotes glycogen re-synthesis during acute and subsequent bouts of endurance exercise."

The eighth tenet reads, "Nutrient timing incorporates the use of methodical planning and eating of whole foods, nutrients extracted from food, and other sources. The timing of the energy intake and the ratio of certain ingested macronutrients are likely the attributes which allow for enhanced recovery and tissue repair following high-volume exercise, augmented muscle protein synthesis, and improved mood states when compared with unplanned or traditional strategies of nutrient intake."

To read all eight tenets,
click here.,Issn_Publishes_Position_Statement_On_Nutrient_Timing.html

Beta-Alanine improves performance in the elderly

Sport Supplement May Help Shield Seniors From Falls

Beta-alanine boosts muscle, balance, study finds

Posted November 19, 2008

WEDNESDAY, Nov. 19 (HealthDay News) -- The dietary supplement beta-alanine (BA) -- widely used by athletes and body builders -- improves muscle endurance in the elderly, according to U.S. researchers.

The finding "could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women," said study author Jeffrey Stout of the University of Oklahoma.

BA is an amino acid that helps form carnosine, which plays a major role in normal muscle function during intense exercise. The more BA, the higher carnosine levels in muscles, the researchers said.

In this study, Stout and his colleagues assessed the fitness levels of 26 elderly men and women before and after they took BA supplements or placebo pills for 90 days.

They found a 67 percent improvement in the fitness levels of those who took BA, compared to a 21.5 percent improvement in the placebo group.

"Our data suggest that 90 days of BA supplementation increased physical working capacity in elderly men and women," the study authors wrote. "These findings are clinically significant, as a decrease in functional capacity to perform daily living tasks has been associated with an increase in mortality, primarily due to increased risk of falls."

The study was published online this month in the Journal of the International Society of Sports Nutrition.