Healthy Participants
Conditions
Brief summary
The aim of this study is to investigate the amino acid kinetics in blood after a bout of strength training and ingestion of different milk protein supplements (native whey, whey protein concentrate 80, hydrolysed whey, microparticulated whey and milk) The investigators hypothesize that native whey will give a faster and higher rise in blood concentrations of leucine compared to the other milk protein supplements.
Detailed description
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 leucine in native whey. The aim of this double-blinded randomized 5-arm cross-over study is to compare amino acid kinetics in blood after a bout of strength training and ingestion of 20 grams of high quality, but distinct, dairy protein supplements (native whey, whey protein concentrate 80, hydrolysed whey, microparticulated whey and milk). Furthermore, the investigators investigate whether differences in amino acid kinetics affect acute blood glucose and urea response, as well as recovery of muscle function after a bout of strength training. The investigators hypothesize that native whey will give a faster and higher rise in blood concentrations of leucine compared to the other protein supplements.
Interventions
OTHERStrength Training
DIETARY_SUPPLEMENTMilk 1%
DIETARY_SUPPLEMENTWhey protein concentrate 80 (WPC-80)
DIETARY_SUPPLEMENTMicroparticulated whey
DIETARY_SUPPLEMENTHydrolyzed whey
DIETARY_SUPPLEMENTNative whey
Sponsors
Arkansas Children's Hospital Research Institute
Tine
Norwegian School of Sport Sciences
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy in the sense that they can conduct training and testing * Able to understand Norwegian language written and oral
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)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Plasma amino acid concentration change from baseline | Blood collected at 0, 30, 45, 60, 90 and 120 min after consumption of protein supplements |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Serum urea change from baseline | Blood collected at 0, 30, 45, 60, 90 and 120 min after consumption of protein supplements. For milk and native whey blood was collected at two additional time points: 22 and 30 hours after consumption of protein supplements | — |
| Muscle force generating capacity change from baseline | Measured before and at 0, 6, 22 and 30 hours after exercise. Only measured after milk and native whey | Measured as unilateral isometric knee extension force (Nm) with 90° in the hip and knee joints. |
| Serum glucose change from baseline | Blood collected at 0, 30, 45, 60, 90 and 120 min after consumption of protein supplements | — |
| Serum creatine kinase change from baseline | Blood collected at 0, 30, 45, 60, 90 and 120 min after consumption of protein supplements. For milk and native whey blood was collected at two additional time points: 22 and 30 hours after consumption of protein supplements | — |
| Muscle soreness change from baseline | Measured before and at 0, 6, 22 and 30 hours after exercise. Only measured after milk and native whey | Measured for m. quadriceps and m. pectoralis major on a visual analog pain scale |
| Jump height change from baseline | Measured before and at 0, 6, 22 and 30 hours after exercise. Only measured after milk and native whey | Measured as counter movement jump on a force plate |
Outcome results
None listed