Clinical trial NCT02909881: Dose Response Oxidation of a Sweet-corn Derived Sugar (PhytoSpherix) During Exercise in Endurance Trained Athletes
Official title: Dose Response Oxidation of a Sweet-corn Derived Polysaccharide (PhytoSpherix) During Exercise in Endurance Trained Athletes
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Hypoglycemia
Keywords: polysaccharide
oxidation
endurance exercise
Lead sponsor: University of Western Ontario, Canada
Sponsor class: OTHER
Collaborators: name: Mirexus Biotechnologies Inc
First posted: 2016-09-21
Enrollment: 8
Sex: MALE
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: PhytoSpherix (Phx) is an all-natural, edible polysaccharide extracted from sweet corn. This carbohydrate is the major muscle fuel for intense exercise and its stores are quite small such that one can run out of it during a single exercise bout. Therefore, Phx should provide significant exercise fuel if consumed during exercise. As a result its intake could enhance intense exercise performance by providing additional fuel. This experiment Will investigate the effects of 4 different dosages of Phx consumed throughout a prolonged exercise bout on carbohydrate and fat utilization as well as its oxidation rate and perception of effort during prolonged intense exercise in trained cyclists. Muscle and liver carbohydrate stores will be examined using a non-invasive ultrasound technique.

Detailed description: Carbohydrate (CHO) is one of the main substrate oxidized during moderate-to-high intensity, endurance-type exercise. It's been shown that CHO feeding during exercise enhances endurance performance and capacity, attributed mainly to the facilitation of greater rates of exogenous CHO oxidation, prevention of hypoglycaemia and sparing of muscle glycogen. Previous studies based on supplementation of glucose during 180 min. of cycling exercise have reported a maximal rate of exogenous CHO oxidation to be about 1 g/min. Other studies have shown that CHO oxidation rates can reach peak values of about 1.3 g/min when a combination of fructose and glucose is ingested at a rate of 1.8 g/min. The limitation in uptake and oxidation of a single CHO source is attributed to its intestinal transporter saturation such that when multiple CHO source is used the uptake and oxidation rate is increased to a greater extent. Currently there is no information regarding Phx uptake or oxidation rate as a CHO source during exercise. Also, it is important to investigate whether Phx as a CHO sport drink can increase performance by sparing muscle and liver glycogen during exercise. Therefore, the objective of this experiment is to measure dose response of Phx oxidation rate during prolonged cycling exercise and its effect on muscle and liver glycogen levels.

Eligibility criteria: Inclusion Criteria:

* Healthy male endurance trained athletes with \>2 y cycling experience; about 2 h/day

Exclusion Criteria:

* Unhealthy athletes, smokers

Primary outcomes:
measure: Oxidation of PhytoSpherixat
timeFrame: 0, 15, 30, 45, 60, 75, 90, 135, 150 min from the beginning of the exercise session
measure: Noninvasive ultrasound measure of glycogen in Vastus lateralis, rectus femoris and liver
timeFrame: 10 min before and 10 min after the 150 min exercise session
Secondary outcomes:
measure: blood glucose concentration
timeFrame: 0, 15, 30, 45, 60, 75, 90, 135, 150 min from the beginning of the exercise session
measure: blood lactate concentration
timeFrame: 0, 15, 30, 45, 60, 75, 90, 135, 150 min from the beginning of the exercise session
measure: Respiratory exchange ratio
timeFrame: At 0, 15, 30, 45, 60, 75, 90, 135, 150 min from the beginning of the exercise session
measure: rate of perceived exertion
timeFrame: At 0, 15, 30, 45, 60, 75, 90, 135, 150 min from the beginning of the exercise session
measure: questionnaire to rate possible gastrointestinal (GI) problems
timeFrame: At 30, 60, 90, 120 and 150 min from the beginning of the exercise session
Other outcomes:
Locations:
city: London
country: Canada
facility: Exercise Nutrition Research Laboratory, Western University
state: Ontario
Study officials:
affiliation: Western University
name: Peter Lemon, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Bandegan A, Huang L, Longstaffe FJ, Lemon PW. Dose-Response Oxidation of Ingested Phytoglycogen during Exercise in Endurance-Trained Men. J Nutr. 2021 Oct 1;151(10):2942-2948. doi: 10.1093/jn/nxab219.