The effects of protein ingestion to maximize endurance-based training adaptations in untrained healthy young men

Physical training can be roughly divided into endurance training and strength
training. Regular endurance training provides an improvement of uptake of
oxygen by the blood, an improvement in the transport of blood and, finally, a
better use of oxygen by the active muscles. Regular strength training on the
other hand, allows for improved control of the muscles, growth in the size of
the muscles and strengthening of the muscles.

Nutrition plays an important role before, during and after exercise.
Carbohydrates are best known for the role they play in the rapid release of
energy during exercise, protein and is mainly known for its role in muscle
recovery after exercise. Previous research has shown that protein
supplementation optimizes the recovery of strength resulting in bigger and
stronger muscles. For endurance training, however, it is currently unclear
whether protein supplementation does improve recovery over a longer period (12
weeks).

The primary aim of this study is to examine the beneficial effects of
additional dietary protein supplementation on the endurance-based exercise
training-induced changes in VO2max, endurance performance, muscle strength,
body composition, mitochondria, muscle proteins and blood in healthy untrained
young men. For a comprehensive insight into the potential underlying mechanisms
of the intervention effects on whole body-, muscle- and myocellullar level, a
broad range of tests will be performed before, during, and after the
intervention period. We hypothesize that additional protein ingestion, on both
training and non-training days, during a 12 week endurance training program
further increases VO2max, endurance performance and type I muscle fibre cross
sectional area when compared to the placebo group.

This study will be a double blind, randomized, placebo-controlled intervention
trial. The total study consists of a screening and an experimental part in
which we will focus on the effects of an exercise intervention program with
nutritional support on central and peripheral function and exercise performance
in untrained healthy young men. We will assess the effects of a 12 weeks
endurance-based training program (3x/wk) with or without additional protein
supplementation on endurance-based training-induced changes in VO2max, type I
and II muscle fibre size, body composition, substrate metabolism and muscle and
exercise performance in healthy untrained young men.

Three times a week endurance training, for a total period of 12 weeks.

Each training session lasts approximately 60 minutes.

Group Intervention: protein supplement (30 g protein). After training and
before bedtime.

Placebo Group: carbohydrate supplement (30 g carbohydrate). After training and
before bedtime.

Testing effort for maximum endurance and strength:
Exercise testing can lead to muscle soreness. This is harmless and after a few
days away.

Infusion needle:
Despite the fact that the blood will be taken with a lot of care and conducted
by an experienced nurse, it is possible that by the puncture and the placement
of the infusion, bruising occurs.

Muscle biopsy
A muscle biopsy is a small procedure in which a small piece of muscle is
removed from the thigh. The muscle biopsy is taken from the right thigh. The
skin and the underlying tissue are locally anesthetized. After this, there is
provided a small incision (0.5 cm) made in the skin and the muscle sheath.
Through this slice of a hollow needle is inserted with which a few chunks of
muscle to be disconnected. After taking the muscle biopsy of the wound edges
are closed with a sterile bandage and a pressure bandage to minimize the chance
of bleeding. The incision will heal completely, but, in some cases, keep
subjects a little scar here on. There are small risks associated with taking a
muscle biopsy. For example, there is a small risk of a hematoma at the end of
the muscle biopsy, in order to counteract the hematoma additional pressure
connection will be made. It may also happen that a subject suddenly feel unwell
while taking or after the muscle biopsy and that the subject will faints.