Anabolic Effects of Whey and Casein After Strength Training in Young and Elderly

Norwegian School of Sport Sciences43 enrolled

Overview

The aim of this study is to investigate the acute anabolic effects of native whey, whey protein concentrate 80 (WPC-80) and milk after a bout of strength training in young and elderly. The investigators hypothesize that native whey will give a greater stimulation of muscle protein synthesis and intracellular anabolic signaling than WPC-80, and that WPC-80 will give a stronger stimulus than milk.

Increasing or maintaining muscle mass is of great importance for populations ranging from athletes to patients and elderly. Resistance exercise and protein ingestion are two of the most potent stimulators of muscle protein synthesis. Both the physical characteristic of proteins (e.g. different digestion rates of whey and casein) and the amino acid composition, affects the potential of a certain protein to stimulate muscle protein synthesis. Given its superior ability to rapidly increase blood leucine concentrations to high levels, whey is often considered the most potent protein source to stimulate muscle protein synthesis. Native whey protein is produced by filtration of unprocessed milk. Consequently, native whey has different characteristics than WPC-80, which is exposed to heating and acidification. Because of the direct filtration of unprocessed milk, native whey is a more intact protein compared with WPC-80. Of special interest is the higher amounts of the highly anabolic amino acid leucine in native whey. The higher levels of leucine can be of great interest for elderly individuals as some studies in elderly has shown an anabolic resistance to the effects of protein feeding and strength training. By increasing levels of leucine one might overcome this anabolic resistance in the elderly. The aim of this double-blinded, randomized, partial cross-over study is to compare the acute fractional protein synthesis and intracellular signaling response to a bout of strength training and intake of 20 grams of protein from either native whey, whey protein concentrate 80 or milk, in young and old individuals. Furthermore, the investigators wil investigate fractional protein breakdown, markers of protein breakdown, amino acid concentrations in blood. The investigators hypothesize that native whey will induce a greater anabolic response than whey protein concentrate 80, and that whey protein concentrate 80 will give a stronger anabolic response than milk.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

Healthy Young Elderly

Interventions

Strength trainingOTHER

Milk 1%DIETARY_SUPPLEMENT

Whey protein concentrate 80DIETARY_SUPPLEMENT

Native wheyDIETARY_SUPPLEMENT

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy in the sense that they can conduct training and testing * Able to understand Norwegian language written and oral * Between 18 and 45, or above 70 years of age Exclusion Criteria: * Diseases or injuries contraindicating participation * Use of dietary supplements (e.g. proteins, vitamins and creatine) * Lactose intolerance * Allergy to milk * Allergy towards local anesthetics (xylocain)

Locations (1)

Norwegian School of Sport Sciences

Oslo, Norway

Outcomes

Primary Outcomes

Mixed muscle fractional synthetic rate

A continous infusion of a stable isotope (phe D5) is used to measure incorporation of tracer into muscle (biopsies from m. vastus lateralis)

Time frame: Three to one hours prior to a bout of strength training and protein consumption

Mixed muscle fractional synthetic rate

A continous infusion of a stable isotope (phe D5) is used to measure incorporation of tracer into muscle (biopsies from m. vastus lateralis)

Time frame: One to five hours after a bout of strength training and protein consumption

Mixed muscle fractional synthetic rate

Two boluses of tracer (phe13C6 and phe15N) was used to measure incorporation of tracer into muscle (biopsies from m. vastus lateralis)

Time frame: From three to five hours after a bout of strength training and protein consumption

Mixed muscle fractional breakdown rate

Two boluses of tracer (phe13C6 and phe15N) was used to measure the dilution of tracer in muscle (biopsies from m. vastus lateralis)

Time frame: From three to five hours after a bout of strength training and protein consumption

Secondary Outcomes

Ratio of phosphorylated to total ribosomal protein S6 kinase beta-1(P70S6K) change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Phosphorylation of phosphorylated to total eukaryotic elongation factor 2 (eEF-2) change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Data from ClinicalTrials.gov

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Phosphorylation of phosphorylated to total eukaryotic translation initiation factor 4E-binding protein 1 (4EBP-1) change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Intracellular translocation of forkhead box O3 (FOXO3a) change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Intracellular translocation of muscle RING-finger protein-1 (Murf-1) change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Intracellular translocation of Atrogin1 change from baseline

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Ubiquitin

Biopsies from m. Vastus Lateralis was analyzed by western blot

Time frame: 30 min before, 1, 2.5 and 5 hours after training and protein intake

Plasma amino acid concentration

Time frame: 180 and 60 min before, and 45, 60, 75, 120, 160, 180, 200, 220 and 300 min after training and protein intake

Muscle force generating capacity change from baseline

Measured as unilateral isometric knee extension force (Nm) with 90° in the hip and knee joints.

Time frame: 15 min before, 15 and 300 min after, and 24 hours after training and protein intake

Plasma glucose

Time frame: 180 and 60 min before, and 45, 60, 75, 120, 160, 180, 200, 220 and 300 min after training and protein intake

Plasma insulin

Time frame: 180 and 60 min before, and 45, 60, 75, 120, 160, 180, 200, 220 and 300 min after training and protein intake

Serum urea

Time frame: 180 and 60 min before, and 60, 10, 180 and 300 min after training and protein intake

Serum ureic acid

Time frame: 180 and 60 min before, and 60, 10, 180 and 300 min after training and protein intake

Serum creatine kinase

Time frame: 180 and 60 min before, and 60, 10, 180 and 300 min after training and protein intake

Change in ATP-binding cassette transporter (ABCA1) messenger ribonucleic acid (mRNA)