The effect of a potato based low-osmolaric glucose polymer drink on gastric distress and running performance*

Sports drinks are a convenient source of carbohydrates (CHO) before or during
exercise. However, due to the high osmolarity of CHO in solutions, CHO drinks
can cause gastric distress during running exercise. Consequently, this can lead
to a reduction is running performance. A newly developed low osmolaric glucose
polymer (LOGP) drink derived from potato starch may lead to a reduced incidence
of gastric distress, and therefore preserve running performance.

To investigate whether two newly developed, potato based LOPG drinks with a
different osmolarity and volume taken before exercise, differently affect
gastric distress after both a short and long term exercise, running
performance, and the rate of gastric emptying compared to an isoenergetic CHO
control.

This is a randomised placebo-controlled trial with a cross-over design. This
study consist of three parts. Firstly, 40 participants will partake in the 3
km-test sessions involving running 3 km to their best extent, after which they
will fill in a questionnaire concerning gastric complaints. They will perform
three 3 km-test sessions, consuming intervention drink 1, intervention drink 2,
and the control drink each once in a crossover fashion, 15 minutes before
exercise. Secondly, all participants will be divided in either intervention
group 1, intervention group 2, or the control group, based on their performance
in the 3 km-test. All participants will partake in an event test which involves
performing in a running event of 10 km, after which they will fill in a
questionnaire concerning gastric distress. The test drink will be consumed 15
minutes before exercise. Thirdly, a subselection of 10 out of the 40
participants will be enrolled in the gastric emptying test sessions. These
sessions involve undergoing a (1-13C)-sodium acetate breath test and blood
glucose measurements. They will perform three sessions, consuming intervention
drink 1, intervention drink 2, and the control drink each once.

The treatment involves taking a CHO solution. Intervention drink 1 consists of
40 g LOGP in 400 mL fluid (10 g CHO*100 ml-1) with an osmolarity of 113
mosmol*kg-1. Intervention drink 2 consists of 40 g LOGP in 200 ml fluid (20 g
CHO*100 ml-1) with an osmolarity of 205 mosmol*kg-1. The control drink consists
of 40 g maltodextrin in 400 ml fluid (10 g CHO*100 ml-1) with an osmolarity of
300 mosmol*kg-1. Each intervention and control drink contains an addition of
2.0 g*l-1 sodium chloride, to closely match commercial sports drinks.

During the study no invasive measurements take place. Participants are asked to
partake in high intensity running exercise sessions. It is not expected that
the participants will consider the exercise sessions burdensome, because they
are healthy, trained individuals with experience in running. Measurements
include filling in a questionnaire concerning gastric distress, collecting
breath samples, and blood samples (by fingerpricking). The provided CHO
beverages are derived from natural starches and are not related to any adverse
effect. Similar LOGP*s (Vitargo® S2, Cluster Dextrin®) have been administered
in research trials and are commercially available, with no signs of negative
consequences from use. Each participant will perform three 3 km-test sessions,
and partake in a 10 km running event after which they will fill in a
questionnaire concerning gastric distress. The total amount of time required
for each participant is 255 minutes. The small subselection of participants who
partake in the three gastric emptying testing sessions require an addition of
270 minutes in total. Participants will receive financial compensation. Aside
from the running event, test procedures will be performed at the research
facility of InnosportLab® Papendal, and the running track of Topsportcentrum
Papendal, Arnhem.