Okay, okay! We get it! Chocolate milk is an effective post-exercise recovery drink! No need to beat a dead horse! The latest blow to the dead horse of proof that drinking chocolate milk promotes muscle recovery after exercise comes out of James Madison University. Researchers compared the effects of chocolate milk and a high-carb drink of equal calories on various markers of recovery in college soccer players after training on four consecutive days. There were no difference between the two drinks in their effects on muscle soreness or performance tests. However, after four days, creatine kinase levels (CK is a marker of muscle damage) were lower in chocolate milk drinkers. The authors of the study, which was published in Medicine & Science in Sports & Exercise, concluded, “Future studies should investigate if the attenuated CK levels observed with chocolate milk have functional significance during more demanding periods of training.” Oh, no! More chocolate milk studies!

Running a marathon beats the heck out of the body. Even walking down a short flight of stairs the next day is difficult. But researchers from England’s Northumbria University have found something that might help: drinking cherry juice before the marathon. Tart cherries are especially rich in antioxidants that can limit the amount of muscle damage that free radicals cause during prolonged running and limit inflammation afterwards. Twenty runners were asked to consume either cherry juice or placebo for five days before running the London Marathon. Measurements of muscle damage, muscle strength, inflammation and soreness were recorded before and after the race. The researchers found that inflammation and oxidative stress were lower after the marathon in the cherry juice group than in the placebo group. Members of the cherry juice group also recovered their strength faster. The findings were published in the Scandinavian Journal of Medicine and Science in Sports.

Overtraining syndrome is an athletic disorder that involves immune system dysfunction. Elevated levels of cytokines, a class of immune cells, is a known marker of overtraining in athletes. There is some evidence that increased carbohydrate intake may offer some protection against immune system stress during periods of heavy training. Researchers from England’s University of Newcastle recently tested this notion in a group of cyclists and triathletes. The subjects were divided into two groups, one of which was placed on a high-carb diet and the other on a moderate-carb diet for 28 days. At the end of this period all of the subjects performed a challenging test workout on indoor bikes.

The researchers measured the cytokine response to this workout and found no difference in the overall response. However, they did find that the anti-inflammatory cytokine response to exercise was reduced by 30-50 percent in members of the moderate-carb group compared to members of the high-carb group. The researchers concluded that the effect was not enough to warrant the high level of carbohydrate intake used in the study.

The following as an abstract of a new study published in the journal Medicine & Science in Sports & Exercise: “Purpose: Dietary supplementation with polyphenols, particularly ellagitannins, may attenuate the muscular damage experienced after eccentric exercise, producing delayed-onset muscle soreness. The purpose of this study was to determine whether ellagitannin supplementation from Wonderful variety pomegranate extract (POMx) improved recovery of skeletal muscle strength after eccentric exercise. Methods: Recreationally active males were randomized into a crossover design with either pomegranate extract (POMx) or placebo (PLA), each given during a period of 9 d. To produce delayed-onset muscle soreness, subjects performed two sets of 20 maximal eccentric elbow flexion exercises with one arm. Maximal isometric elbow flexion strength and muscle soreness as well as serum measures of creatine kinase, myoglobin, interleukin 6, and C-reactive protein were made at baseline and 2, 24, 48, 72, and 96 h after exercise. Results: With both treatments, strength was similarly reduced 2 h after exercise (i.e., 72% of baseline), and recovery of strength was incomplete after 96 h (i.e., 91% of baseline). However, strength was significantly higher in POMx compared with that in PLA at 48 h (85.4% ± 2.5% and 78.3% ± 2.6%, P = 0.01) and 72 h (88.9% ± 2.0% and 84.0% ± 2.0%, P = 0.009) after exercise. Serum markers of inflammation and muscle damage did not provide insight regarding possible mechanisms. Conclusions: Supplementation with ellagitannins from pomegranate extract significantly improves recovery of isometric strength 2-3 d after a damaging eccentric exercise.”

In the good old days, coaches withheld water from athletes during training to “toughen them up”. Now we know that’s crazy, right? While there is no known benefit associated with intentional dehydration, there is some evidence that the old-school logic of toughening up athletes through the deprivation of sustenance may apply to carbohydrate intake in training. Recent research has indicated that performing endurance training in a carbohydrate-deprived state results in greater gains in muscular oxidative capacity than doing the same training with normal carbohydrate intake. Now scientists from McMaster University have shed light on the mechanism underlying this effect in a new study published in the Journal of Applied Physiology.

Ten men performed a workout consisting of 4 x 5 minutes at 90 percent VO2max on stationary bikes twice on the same day with three hours of recovery between sessions. One week later, this protocol was repeated. Half the men were given a high carbohydrate drink after the morning workout in the first trial and a zero-calorie placebo after the morning workout in the second trial, while the other half of the men received the drinks in the opposite order. The authors of the study found increased levels of a compound known as p38 MAPK that is involved in mitochondrial biogenesis following the afternoon workout in the placebo trial–that is, the workout performed in a carbohydrate-depleted state. Mitochondria are organelles within muscle cells where aerobic metabolism occurs, and increased mitochondrial density is one of the main effects of aerobic exercise that increases the oxidative capacity of the muscles. This study suggests that p38 MAPK is a nutrient-sensitive signalling molecule that is most active when exercise is performed in a carbohydrate-depleted state.

The dairy industry has been pushing hard lately to establish milk as an alternative to the protein shakes and recovery drinks that exercisers and athletes often consume after exercise by funding lots of studies designed to prove that milk works just as well, or better. The latest comes of of Washington University and was published in Applied Physiology, Nutrition and Metabolism. Ten trained cyclists and triathletes complete a high-intensity interval session on stationary bikes and then performed an exhaustive ride at 85% VO2max 15-18 hours later. They repeated this protocol one week later. In random order, the athletes were given chocolate milk immediately after one session and an isocaloric alternative immediately after the other. There was no difference in the effects of the two beverages on the subsequent performance ride or in muscle damage levels. Given that the alternative beverage provided essentially the same nutrition as the chocolate milk (it provided the same amounts of carbohydrate and total calories), I can’t imagine why the researchers would have expected to see any differences.

Does vitamin E supplementation protect the muscles against exercise-induced damage? It depends on whom you ask. The research keeps going back and forth. The latest study to look at the question, by Brazilian researchers, has yielded positive results. Twenty-one young male subjects were given either supplemental vitamin E or placebo for two weeks and then subjected to a resistance workout emphasizing eccentric movements. Muscle damage, soreness, and inflammation were measured for seven days after the workout. Soreness and muscle damage markers were lower in the vitamin E group, but inflammation was found to be equal in the two groups. So there you go.

A barrage of recent studies has suggested that antioxidant supplementation offers no benefits to trained athletes, and that it may even interfere with some physiological adaptations to training. Now comes a study in Medicine & Science in Sports & Exercise that suggests antioxidant supplementation does not reduce free radical damage to muscle cells in a high-intensity endurance effort and may also inhibit muscle recovery. Twenty kayakers were given either placebo or an antioxidant containing 272 mg of vitamin E, 400 mg of vitamin C, 30 mg of beta-carotene, 2 mg of lutein, 400 [mu]g of selenium, 30 mg of zinc, and 600 mg of magnesium daily for four weeks. Before the supplementation period and again at the end of it, all subjects completed a 1000m kayak race. The researchers found that while antioxidant supplementation did increase blood levels of antioxidants, it did not reduce lipid peroxidation (free radical damage to cell membranes) caused by the race effort compared to placebo. What’s more, levels of creatine kinase, a marker of muscle damage, decreased significantly more over the four-week study period in the placebo group than in the antioxidant group, suggesting that antioxidant supplementation may have interfered with muscle recovery.

Researchers at Shinshu University in Japan recently studied the effects of post-exercise carbohydrate and protein supplementation on blood plasma volume and exercise thermoregulation in older men. One of the important normal adaptations to aerobic exercise training is an increase in blood plasma volume that increases one’s aerobic capacity and one’s thermoregulatory capacity. The authors of this study sought to test the hypothesis that consuming carbohydrate and protein after exercise would facilitate this adaptation.

Fourteen men with an average age of 68 years cycled for one hour, three times per week, for eight weeks. Half of them received a carb-protein supplement after each workout and the other half received a placebo. Before and after training, researchers measured the subjects’ blood plasma volume, stroke volume and core body temperature during 20 minutes of cycling at 30 degrees celsius. They found that plasma volume increased by 6 percent and stroke volume during exercise increased by 10 percent in the carb-protein group with no changes in the placebo group. Two further markers of thermoregulatory capacity - chest sweat rate and forearm vascular conductivity - increased by 80 and 18 percent, respectively, in the carb-protein group with no changes in the placebo group.

The authors of the study concluded, “Thus, post-exercise protein-CHO supplementation during training caused PV expansion and facilitated thermoregulatory and cardiovascular adaptations, possibly providing a new training regimen for older men.”

Several recent studies have demonstrated that carbohydrate and protein taken together after exercise are more effective than carbohydrate alone in stimulating muscle glycogen synthesis. What is not known is whether the type of protein is important. Japanese researchers recently sought to answer this question by feeding rats with one of four different types of protein - whey protein, whey protein hydrolysate, casein hydrolysate or branched-chain amino acids - along with carbohydrate after exercise and measuring muscle glycogen levels. They found that muscle glycogen levels were significantly higher two hours after exercise in rats that received carbohydrate with whey protein hydrolysate. The concentration of two enzymes associated with glycogen synthesis were also measured and found to be significantly higher in rats receiving whey protein hydrolysate. Hydrolyzed proteins are believed to be more quickly absorbed than intact proteins. This may explain why whey protein hydrolysate stimulated faster muscle glycogen synthesis in this study.