Stimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals

Abstract

Sarcopenia is a well-known phenomenon in elderly individuals and resistance exercise together with sufficient amino acid (AA) availability has proved to be a counteractive implement. However, the source of AA and supplement timing require further investigation. The objective was to compare muscle protein synthesis (MPS) to intakes of whey and caseinate after heavy resistance exercise in healthy elderly individuals, and, furthermore, to compare the timing effect of caseinate intake. Twenty-four elderly men and women (mean ± SEM; 68 ± 1 years) were randomized to one of four groups: caseinate intake before exercise (CasPre), caseinate intake immediately after exercise (CasPost), whey intake immediately after exercise (Whey), or intake of a non-caloric control drink (Control). Muscle myofibrillar and collagen fractional synthesis rates (FSR) were measured by a primed continuous infusion of L-[1-(13) C]leucine using labeled proteins during a 6-h recovery period. No differences were observed in muscle myofibrillar and collagen FSR with Whey (0.09 ± 0.01%/h) compared with CasPost (0.09 ± 0.003%/h), and it did not differ between CasPre (0.10 ± 0.01%/h) and CasPost. MPS does not differ with whey and caseinate feeding immediately after heavy resistance exercise in elderly individuals, and MPS is similar with caseinate ingestion before and after exercise.

Effects of skeletal muscle energy availability on protein turnover responses to exercise

“…Previous studies investigating the feeding-induced stimulation of MPS with whey compared with soy or casein protein have shown greater Pennings et al, 2011;Tang et al, 2009) or similar (in the case of casein) (Dideriksen et al, 2011;Reitelseder et al, 2011;Soop et al, 2012;Tipton et al, 2004) MPS responses in humans, although the cellular basis for these divergent responses is not clear and may be attributable to differences in the type of an individual protein ingested. For example, in some studies where no differences in MPS induced by protein ingestion (i.e.…”

“…For example, in some studies where no differences in MPS induced by protein ingestion (i.e. casein versus whey) post-REX were observed, caseinate was the type of casein ingested (Dideriksen et al, 2011;Reitelseder et al, 2011) compared with the superior effect of whey when miceller casein was the protein source Tang et al, 2009). These differences may be ascribed to the window of biopsy sampling time points not capturing the optimal time frame (i.e.…”

Efectos de los suplementos de proteína y aminoácidos de cadena ramificada en entrenamiento de fuerza: revisión bibliográfica

“…Una vez tratadas algunas de las quinasas responsables de las rutas metabólicas de señalización muscular, se muestra como la SPM aumenta en el postejercicio (durante las ≈5 horas de recuperación), a pesar de protocolos de suplementación y entrenamiento distintos 29,31,46,[60][61][62][63]67,68 . No obstante, Ferreira y Cols.…”

Influence of Amino Acids, Dietary Protein, and Physical Activity on Muscle Mass Development in Humans

“…The effects of whey and casein have also been investigated at a skeletal muscle-specific level at rest and in relation to resistance exercise [114,115,116,117,118,119,120]. Whey and casein/caseinate have been found to have similar hypertrophic effects when measured for 0–6 h of recovery [114,116,117].…”

“…Whey and casein/caseinate have been found to have similar hypertrophic effects when measured for 0–6 h of recovery [114,116,117]. The net balance of phenylalanine across the limb was equal with ingestion of whey or casein proteins after resistance exercise [114] and, thus, it does not seem to be influenced by the different digestion rates of whey and casein.…”