4 weeks of supplementation with keratin equals gaining 1 kilo of muscle
A bio-available form of keratin - that's the protein that makes up hair, nails and feathers - does not make endurance athletes perform better, exercise scientists from the University of Massey in New Zealand report in the Journal of the International Society of Sports Nutrition. But their research also
shows that keratin, however strange it may sound, helps athletes to gain more muscle mass.
For 4 weeks, the researchers gave 15 trained endurance athletes 0.8 grams of a liquid keratin preparation every day. This was the experimental condition.
The keratin supplememt was made by Keraplast. [keraplast.com] Keraplast sponsored the research. Keraplast makes keratin from chicken feathers, and sells its keratin mainly to producers of cosmetic products.
The keratin dose was on the high side. An athlete weighing 70 kilos will use 56 grams of keratin per day. Hmm.
On another occasion, the researchers gave the athletes a similar amount of casein every day. This was the placebo condition.
The researchers had the athletes cycle before and after the administration of the keratin [KER] and the placebo [CAS], and during this exercvise test they determined their performance. They could not detect any positive effects of supplementation with keratin.
The researchers had hoped that keratin supplementation would increase more hemoglobin levels and red blood cell counts, but this was not the case.
However, the researchers discovered to their surprise that during the supplementation with keratin the subjects gained almost a kilo of lean body mass - read: muscle mass. This did not happen during the administration of the placebo. Apparently, keratin has a special muscle building effect. At least in endurance athletes.
"Despite not inducing any significant changes in blood parameters, VO2 or performance measures, soluble keratin was well-tolerated by participants, and has the potential to be used as a high-protein supplement", write the researchers.
"Soluble keratin may provide a more effective alternative to casein as a protein supplement in those who wish to increase lean body mass in conjunction with an aerobic exercise program. These people potentially include older adults, athletes, and persons in the recovery phase of medical intervention or sickness where maximal rates of lean body mass accretion are necessary. The use of keratin supplementation in strength-based athletes is thus an area of future research."
J Int Soc Sports Nutr. 2018 Sep 27;15(1):47.
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