The effect of glycine propionyl-L-carnitine (GPLC) on repeated high-intensity stationary cycle sprints was recently tested. In a double-blind, placebo-controlled, crossover design, 24 male resistance-trained subjects participated in two test sessions separated by one week. Testing was performed 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose, in randomized order. Researchers found that short-term oral supplementation of GPLC can enhance peak power production in resistance-trained males with significantly less lactate accumulation.15 There aren’t many studies on GPLC; however, this one certainly lends support to using this supplement to enhance anaerobic performance.
Omega-3 Fatty Acids
Not typically thought of as a performance-enhancing aid, nonetheless, omega-3s are among the most important supplements you can take (unless you eat plenty of fish). In fact, fish oil supplements and regular exercise both reduce body fat and improve cardiovascular and metabolic health. In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet, resulted in approximately 1 kilogram more weight loss after four weeks than a similar diet without seafood or supplement of marine origin.16 Certainly, using fish oil supplements or the omega-3 fatty acids (EPA and DHA) should be taken for health reasons as well. Folks who consume plenty of fish are less apt to be depressed, and it diminishes the risk of various cancers and cardiovascular disease, too. Oops, did I just mention health?
Protein— Whey and Casein
Whey is perhaps the best single source of protein you can consume. Considered a ‘fast’-acting protein, whey has been shown to have lean mass-promoting effects. Muscle protein synthesis in young men is greater after whey hydrolysate or soy protein consumption as opposed to casein, both at rest and after resistance exercise.17 I’d suggest that you consume whey pre- and or post-workout to maximize the benefits of exercise.
Another interesting benefit of whey protein is that it decreases hunger more than casein or soy protein.18 This doesn’t mean casein is not effective; in fact, casein may be the best nighttime protein because of its ‘slow’ digesting properties.19 A recent study found that consuming casein in the evening worked better than consuming it during the post-workout, nutrient-timing window.20
So here’s my take: during the pre- or post-workout window, go for the whey; but for maximal anabolism at night, go slow and drink that casein.
Who would have thought? Vitamin D deficiencies in folks who live in Florida?21 The new info on vitamin D is exciting in that it may be the missing link in our supplement arsenal. There is convincing science that indicates seasonal variation in athletic performance; meaning that it peaks when 25-hydroxy-vitamin D [25(OH)D] levels peak, declines as they decline, and reaches its lowest point when 25(OH)D levels are at their lowest.
A recent study involving six months of supplementation with calcium and cholecalciferol found it was safe and efficient in improving 25(OH)D levels and lower-limb muscle strength in the elderly, even without regular exercise.22 Also, there’s interesting work showing that vitamin D also increases the size and number of type II (fast-twitch) muscle fibers.23
So how much should you take? Well, the current recommended daily allowance is a paltry 200-600 IUs. That is way too low, my friend. Way too low. According to Hector Lopez, M.D., “Most children and adults need at least 1,000 IU per day, and people with chronic musculoskeletal pain or orthopaedic injury would benefit from well over 2,000 IU of supplemental vitamin D3, also called cholecalciferol.”
So either take your supplement, or you can go out in the sun. I prefer the latter.
So there you got it. Eating clean (choose unprocessed carbs, plenty of protein, and lots of healthy fats) in combination with beta-alanine, BCAA, caffeine, creatine, GPLC, omega-3 fatty acids, supplemental protein (whey and casein) and some vitamin D. With this nutritional and supplement arsenal, you too will attain a dominating physique.
Jose Antonio, Ph.D., is vice president of the National Strength and Conditioning Association. He has a Ph.D. in muscle physiology and is chief executive of the International Society of Sports Nutrition.