Thursday, September 21, 2017

How to handle exercise related muscle cramps

We've all experienced muscle cramps at one point or another. While theories abound, there is limited consensus on why exercise-associated muscle cramps (EAMC) develop and how to get rid of them.

Etiology: The most widely held beliefs for why people develop cramps are (a) dehydration and electrolyte imbalance and (b) altered neuromuscular control. Science favors the latter explanation. In a non-cramped state, there is a balance between the activity of muscle spindles and the activity of golgi tendon organs. Muscular overload or fatigue, as well as other factors, causes an imbalance in the activity of these local receptors. The result is an overall increase in alpha motor neuron activity, which ultimately produces a cramp.

Risk factors: Some hypotheses as to why people might experience EAMC include age, body size, exercise intensity and duration, previous or current injury, gender, family history, genetics, and a history of EAMC. The strongest risk factors are a history of EAMC, male gender, and prolonged and relatively vigorous endurance exercise. Cramps may affect men more than women because men possess more fast-twitch muscle fibers, which fatigue more quickly than slow-twitch fibers. Also, women oxidize more fat and less carbohydrate than men, which may make them less prone to overload compared with men. These are merely theories, however.

Treatment: Common treatment practices include electrical cramp induction, kinesiotaping and compression garments, massage therapy, electrolyte supplementation and hydration, corrective exercise, stretching, quinine, pickle juice, and hyperventilation strategies. Stretching seemed to offer the greatest relief.
Prevention of EAMCD should attempt to offset muscular overload and fatigue. Strategies might include foam rolling or massage, scheduling adequate rest, and placing special emphasis on muscular balance in resistance training. Stretching still appears to be the best treatment for an acute bout of EAMC.

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Monday, September 4, 2017

Don't give frozen foods the cold shoulder

People tend to frown on frozen vegetables and fruits, but fresh isn't always best. In a paper published in the June 2017 issue of the Journal of Food Composition and Analysis, researchers measured the nutritional content (vitamin C, vitamin A, and folate) of three types of produce--fresh, frozen, and fresh-stored (purchased fresh and then refrigerated for 5 days)--over a 2 year span. Items examined were broccoli, green beans, blueberries, and strawberries.

In the majority of cases, vitamin content did not vary among the three categories, but when there were significant differences, frozen fruits and veggies bested fresh-stored versions more often than not. While fresh produce is typically most nutrient-dense at harvest, nutrients degrade during shipping, while foods sit on store shelves and until we retrieve the items from our refrigerators. On the flipside, the frozen counterparts are flash-frozen almost immediately after harvest, which locks in nutrients and keeps them from degrading.

The takeaway? Buying fresh fruits and veggies from local sources and eating them immediately is probably still best, but convenient and budget-friendly subzero produce is a nutritious fallback. Besides, people who work subzero fruits and vegetables into their diets have been shown to benefit from higher produce intakes overall than those who shun them, and the former also have higher intakes of essential nutrients like potassium and calcium.

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Stress, Weight Gain, and Exercise

School work, social situations, family challenges--young kids are faced with a great deal of pressure and perhaps lack the proper outlets to handle it. And as previous research has shown, stress and weight sometimes go hand in hand. A new study shows that exercise may help kids manage stress and prevent weight gain. Parents of 325 children around 7 years old provided information about the children's stress and physical activity levels. The youngsters then completed a 20-meter shuffle test to measure fitness levels and underwent body mass index (BMI), skinfold and waist circumference assessments. 
 
The researchers found that "children experiencing elevated school related stress had lower BMI, body fat, and waist circumferences if they had high fitness and physical activity levels, as compared with their less active peers." The findings indicate that policies aimed at reducing overweight and obesity should include the promotion of physical activity both inside and outside the school context. In their conclusion, researchers also highlighted the importance of strengthening children's capacities to cope successfully with school-related pressures.