Doctor's Orders: An Apple a Day
Fruit is one of my favorite pre-workout carb sources, particularly apples. Apples contain high amounts of polyphenols, which are powerful antioxidants that can lower body fat, raise muscle strength, and reduce muscle fatigue. One study, published in the journal Medicine & Science in Sports & Exercise, gave rats apple polyphenols and examined their weight, body fat percentage, the strength of their gastrocnemius (or calf) muscles, and how fatigued the gastrocs were after exercise. After three weeks, the polyphenol-fed rats had about 30 percent less body fat than the ones in the placebo group, demonstrated a whopping 100 percent more strength in their calves, and experienced significantly less muscle fatigue.
In another 2007 study, this one published in the Journal of Oleo Science, human subjects who took apple polyphenols for three weeks reduced their body weight and, critically, their abdominal fat levels. Scientists postulate that apple polyphenols activate genes that turn on fat-burning and slow fat storage. Using more fat as fuel may also be the reason why muscle fatigue was reduced, and the polyphenols antioxidant activity may reduce the damage muscles incur during exercise and result in increased strength.
The latest research shows that one of the polyphenols in apples (mainly found in the peel), ursolic acid, may be responsible for a good deal of these beneficial properties. University of Iowa researchers fed mice a diet supplemented with ursolic acid for 5 weeks and found that those getting the ursolic acid gained 15 percent more muscle mass while simultaneously losing more body fat than those not getting additional ursolic acid. Plus, the mice getting the ursolic acid were stronger. It appears that ursolic acid works to boost muscle growth and strength by increasing insulin-like growth factor-I (IGF-I) levels in muscle cells. This is one of the growth factors that I have studied extensively in the lab. It is critical for stimulating muscle growth.
Eating a large apple with your pre-workout whey shake can provide around 200 mg of polyphenols to boost strength, energy, and even fat burning.
Remember that every rest day should be an active rest day. Rest days are for recovery; they're not an excuse to be lazy. Get out and hit 15-30 minutes of HIIT cardio today, or perform 30-60 minutes of your favorite activity: hiking, biking, walking, playing a sport, etc.