InTerlaboratory Evaluation of a GastroIntestinal Activity Ergometertest in Non-intense Trained PersOns

Ergometer tests are frequently used to evaluate health-promoting effects of
nutritional concepts. This is based on the notion that intense exercise, as a
stressor, modulates intestinal and immune responses. Notably, kinetic changes
of parameters (biomarkers) of gastro-intestinal or immunological alterations
may allow the assessment of an individual*s fitness to respond to any stressor,
including infections or inflammatory diseases. However, ergometer tests have
not yet been properly validated, for instance with regard to lab
transferability. In addition, a validated set of relevant e.g.
function-related, biomarkers is not available, nor is clear how the extent of
exercise intensity influences these biomarkers.
Recently, we have finished the GRINTA! study, which was coded NL 49412.081.14
Gastro-intestinal permeability and intense physical activity. In this study, we
have included three exercise protocols that differed in extent of intensity (60
min 70%, 50%, interval 55%/85% of individual Wmax). These protocols were
compared with each other, and with a rest-protocol and a dehydration protocol.
To reduce variation we only tested young and fit (but not excessively trained)
male volunteers, that nevertheless could barely fulfill the toughest protocol
(Wmax 70% with dehydration). Results of the GRINTA! study show clear kinetic
changes in a range of gastro-intestinal (e.g. citrulline, iFABP), immunological
(e.g. leukocytes, including NK, macrophages, neutrophils) and general (e.g.
insuline, cortisol) parameters. In addition, we found that a number of
parameters also changed in the non-intense protocol of 50% Wmax, and that most
parameters were already changed after 30 minutes of the 70% Wmax protocol.

The aim of the RAAK-PRO Diagrams project is to standardize the bicycle
ergometer test. Another important aim of the project is to adapt the
test-protocol so that it can be used to perform nutrition intervention studies
with less-fit individuals, e.g. obese T2D patients. Results of the GRINTA! are
very promising with regard to both aims.
An important step in standardization of any given test-method is to assess its
lab transferability and its interlaboratory variation. We therefore propose to
perform the bicycle ergometer test in 2 independent laboratories. In these
studies, we intend to also test a less intense exercise protocols (30 min 70%
Wmax, 50% Wmax).
We hypothesize that performance of the exercise protocols of 70% and 50% Wmax
on different locations will show comparable effects on immune response and
intestinal barrier function. In order to develop a test that can be applied to
a broad population, we further hypothesize that less intense exercise also
sufficiently influence various biomarkers.

The primary objective is to evaluate the lab transferability of the exercise
model as used in the GRINTA! study. This will be achieved by comparing the
effect of exercise on biomarkers in blood, urine and saliva in two different
laboratories. These studies will be done in young male volunteers and
biomarkers are selected based on the GRINTA! study. The secondary objective is
to determine whether an intermediate-intense (moderate) exercise sufficiently
affects the selected biomarkers.

Randomized cross-over trial with 4 different experimental exercise protocols:
1) rest, 2) 60 min cycling at 70% Wmax, 3) 30 min cycling at 70% Wmax and 4)
60 min cycling at 50% Wmax.

Ingestion of multi-sugar and glutamine- alanine solutions to evaluate
intestinal barrier function in 4 different experimental protocols as described
in study design.

The risks for the subjects related to this study are minor. The exercise that
has to be performed is moderate to intense and will be well tolerated within
this group of participants, i.e. recreationally trained cyclists. There is a
small risk of bruising due to the blood sampling procedures. The ingestion of
the test products is not associated with an additional risk and is well
tolerated. There is no direct health benefit for the subjects but the
measurement of Wmax and VO2max can be of interest for this group of
recreationally trained cyclists. Next to this, subjects will receive a
financial compensation of ¤75,- for each experimental condition, i.e. ¤300,-
if they complete the study. Blood, urine, and saliva will be collected at
several time points of the study to establish kinetics of changes, which means
that subjects have to be in the lab for 6 hrs and have to come back to the lab
at 24 hrs after start of the cycling test. Next to this, the subjects have to
adhere to specific guidelines the last days before and during each test day and
furthermore they will have to keep a log on diet, illness and exercise during
the whole study period.