"Long before it's in the papers"
January 27, 2015


Work out? Some of those muscle-building drinks can actually work, researchers say

Aug. 19, 2011
Courtesy of the Amer­i­can So­ci­e­ty for Nu­tri­tion
and World Science staff

Some pro­tein drinks mar­keted to help weight lifters build muscle ac­tu­ally work, but must be tak­en the right way for the best re­sults, ac­cord­ing to re­search newly pub­lished in a nu­tri­tion jour­nal.

In reg­u­lar ex­er­cis­ers, es­pe­cially weight lifters, the mus­cles un­dergo a con­tin­u­ous cy­cle of break­down—dur­ing ex­er­cise—and re­build­ing af­ter­ward. Ath­letes have long ex­pe­ri­mented with ways to en­hance these phys­i­o­logical re­sponses to boost mus­cle growth. One pop­u­lar tac­tic is the use of high-pro­tein bev­er­ages, of­ten dairy-based drinks en­riched with whey pro­teins. 

Many stud­ies have doc­u­mented a ben­e­fi­cial ef­fect from these prod­ucts, sci­en­tists say. Of par­tic­u­lar in­ter­est, they main­tain, is the ef­fect of the es­sen­tial ami­no ac­id leu­cine in these prod­ucts. Two pa­pers, pub­lished in the Sep­tem­ber 2011 is­sue of The Amer­i­can Jour­nal of Clin­i­cal Nu­tri­tion, re­port the re­sults of two stud­ies billed as in­de­pend­ent re­search con­ducted to un­der­stand bet­ter how ami­no ac­ids in­flu­ence pro­tein pro­duc­tion in recrea­t­ional ath­letes.

“It makes good sense that con­sum­ing a food con­tain­ing high-qual­ity pro­tein like milk dur­ing and/or im­me­di­ately fol­low­ing ex­er­cise would help mus­cles get stronger,” said nu­tri­tion sci­ent­ist Shel­ley McGuire, a spokesper­son for the Amer­i­can So­ci­e­ty for Nu­tri­tion, which pub­lishes the jour­nal.

In the first stu­dy, re­search­ers led by Stu­art Phil­lips of Mc­Mas­ter Uni­vers­ity in Can­a­da in­ves­t­i­gated wheth­er postex­er­cise mus­cle pro­tein pro­duc­tion is dif­fer­ent when a 25-gram dose of whey pro­tein is con­sumed right af­ter ac­ti­vity, com­pared with doses one-tenth the size, con­sumed 10 times over an ex­tend­ed pe­ri­od. 

In the sec­ond study, led by Ste­fan Pasi­akos from the U.S. Ar­my Re­search In­sti­tute of En­vi­ron­men­tal Med­i­cine, ac­tive-duty soldiers drank a high-pro­tein drink with 10 grams of pro­tein as es­sen­tial ami­no ac­ids, con­tain­ing 1.87 or 3.5 grams of leu­cine, while ex­er­cis­ing on a sta­t­ionary bicy­cle. In both stud­ies, mus­cle pro­tein pro­duc­tion was eval­u­at­ed af­ter the work­out.

Con­sum­ing the large dose of whey pro­tein im­me­di­ately af­ter ex­er­cise in­creased mus­cle pro­tein pro­duc­tion more than when pe­ri­odic smaller doses of pro­tein were con­sumed, the first study found. In the sec­ond stu­dy, mus­cle pro­tein syn­the­sis was one-third great­er af­ter con­sump­tion of the leu­cine-en­riched pro­tein bev­er­age than af­ter the lower-leu­cine drink. Pro­tein in­take im­me­di­ately af­ter ex­er­cise seems to be best, re­search­ers concluded, and leu­cine may play an es­pe­cially im­por­tant role in stim­u­lat­ing mus­cle growth.

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Some protein drinks marketed to help weight lifters boost their results actually work, but must be taken the right way for the best results, according to research newly published in a nutrition journal. In regular exercisers, especially weight lifters, the muscles undergo a continuous cycle of breakdown—during exercise—and rebuilding afterward. Athletes have long experimented with ways to enhance these physiologic responses to boost muscle growth. One popular tactic is the use of high-protein beverages, often dairy-based drinks enriched with whey proteins. Many studies have documented a beneficial effect from these products, scientists say. Of particular interest, they maintain, is the effect of the essential amino acid leucine in these products. Two papers, published in the September 2011 issue of The American Journal of Clinical Nutrition, report the results of two studies billed as independent research conducted to understand better how amino acids influence protein production in recreational athletes. “It makes good sense that consuming a food containing high-quality protein like milk during and/or immediately following exercise would help muscles get stronger,” said nutrition scientist Shelley McGuire, a spokesperson for the American Society for Nutrition, which publishes the journal. In the first study, researchers led by Stuart Phillips of McMaster University in Canada investigated whether postexercise muscle protein production is different when a 25-gram dose of whey protein is consumed right after activity, compared with doses one-tenth the size, consumed 10 times over an extended period. In the second study led by Stefan Pasiakos from the US Army Research Institute of Environmental Medicine, active-duty military personnel drank a high-protein drink with 10 grams of protein as essential amino acids, containing 1.87 or 3.5 grams of leucine, while exercising on a stationary bicycle. In both studies, muscle protein production was evaluated after the workout. Consuming the large dose of whey protein immediately after exercise increased muscle protein production more than when periodic smaller doses of protein were consumed, the first study found. In the second study, muscle protein synthesis was one-third greater after consumption of the leucine-enriched protein beverage than after the lower-leucine drink. Protein intake immediately after exercise seems to be best, researchers said, and leucine may play an especially important role in stimulating muscle growth in the postactivity recovery period.