Effect of Glycogen Replenishment on Time Trial Performance Following a Glycogen Lowering Exercise

NCT03682861 | Unknown DMC

• 1 other identifier: 112747
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Fifteen endurance-trained male/female will be randomly assigned to do four exercise and nutrition trials involving ingestion of four different concentrations of sweet corn derived starch (food component) in water (0, 1, 1.5 and 2 g. kg-1. h-1). Each trial will be separated by at least one week. During these four experimental trials athletes will be subjected to a glycogen-lowering cycling exercise protocol followed by a 4-h post-exercise recovery period (2h feeding then 2 hours of rest). At the end of 4-h period they will do a 20 kilometre time trial test on a stationary bike in a laboratory condition to measure the effect of different glycogen repletion rates on exercise performance.

Conditions

Carbohydrate Metabolism

Outcome Measures

Primary Outcomes (1)

• 20 km time trial

  participants will ride for 20 km on a stationary bike and time to finish will be measured

  40 minutes

Secondary Outcomes (5)

• VO2

  2 hours

• Blood glucose

  2 hours

• VCO2

  2 hours

• Serum insulin

  2 hours

• Blood lactate

  2 hours

Study Arms (2)

Placebo

PLACEBO COMPARATOR

Placebo flavored drink similar to treatments but with no energy will be ingested post glycogen lowering exercise, followed by a 20 km time trial intervention

Behavioral: 20 km time trial performance; Behavioral: Glycogen lowering exercise

Carbohydrate drinks

EXPERIMENTAL

Sweet corn derived starch mixed in water at three different concentrations (6%, 12% and 18%) will be ingested post glycogen lowering exercise, followed by a 20 km time trial intervention

Behavioral: 20 km time trial performance; Behavioral: Glycogen lowering exercise

Interventions

20 km time trial performance BEHAVIORAL

20 km time trial cycling test will be conducted to measure the effect of different drinks on time

Carbohydrate drinks; Placebo

Glycogen lowering exercise BEHAVIORAL

Glycogen will be lowered using a 10-min warm-up period at a workload of 50% max wattage power output (Wmax). Thereafter, participants will be instructed to cycle 2-min block periods at alternating workloads of 90% and 50% of Wmax, respectively. This will be continued until the participants are no longer able to complete the 2 min at 90% Wmax. That moment will be defined as the time at which the individual is unable to maintain cycling speed at 60 revolutions/min. At that moment the high-intensity block will be reduced to 80% Wmax. Again, athletes will cycle until they are unable to complete a 2-min block at 80% Wmax, after which the high-intensity block will be reduced to 70% Wmax. Finally, participants will be allowed to stop when pedalling speed could not be maintained at 70% Wmax.

Carbohydrate drinks; Placebo

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• are a healthy male or female endurance athlete of 18- 40 years of age
• have ≥2 y endurance training experience; training for ˃1 h/day

You may not qualify if:

• Have symptoms or take medication for respiratory disease
• Have symptoms or take medication for cardiovascular disease
• Have symptoms or take medication for metabolic disease
• Have symptoms or take mediation for neuromuscular disease
• Use heart rate or blood pressure medications
• Use any medications with side effects of dizziness, lack of motor control, or slowed reaction time
• Have any cardiovascular or neuromuscular limitations to exercise
• Are pregnant or find out that you are pregnant during experiment

Sponsors & Collaborators

• Western University, Canada: lead

Study Sites (1)

Exercise Nutrition Laboratory (Western University)

London, Ontario, N6A 3K7, Canada

RECRUITING

Related Publications (2)

• Ivy JL. Glycogen resynthesis after exercise: effect of carbohydrate intake. Int J Sports Med. 1998 Jun;19 Suppl 2:S142-5. doi: 10.1055/s-2007-971981.

  PMID: 9694422 RESULT

• Upshaw AU, Wong TS, Bandegan A, Lemon PW. Cycling Time Trial Performance 4 Hours After Glycogen-Lowering Exercise Is Similarly Enhanced by Recovery Nondairy Chocolate Beverages Versus Chocolate Milk. Int J Sport Nutr Exerc Metab. 2016 Feb;26(1):65-70. doi: 10.1123/ijsnem.2015-0056. Epub 2015 Aug 27.

  PMID: 26314086 RESULT

Study Officials

• Peter Lemon, PhD

  Western University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Peter Lemon, PhD

CONTACT

519 6612111; plemon@uwo.ca

Arash Bandegan, PhD

CONTACT

519 6612111; abandeg@uwo.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Flavoured water placebo drink with no energy or carbohydrate drinks in opaque bottles to keep participant blinded
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: It is a repeated measure design where each participant will undergo all four treatment in a randomized fashion to prevent any order effect. Treatments (recovery drinks) include a placebo which will be similar in taste and flavour to other treatments and three carbohydrate containing drinks mixed in water at different concentrations. Design of the study is composed of three main stages: 1) glycogen lowering exercise, 2) glycogen replenishment and rest and 3) performance based, timed cycling exercise. All participants will arrive fasted to the laboratory, performing an exercise protocol that lowers their glycogen levels, followed by ingestion of different drinks (every 30 min) during 2 hours of a 4 hour rest and finally performing a 20 km stationary bike test for the time to finish to evaluate the effect of recovery drinks ingested.

Study Record Dates

• First Submitted: September 21, 2018
• First Posted: September 25, 2018
• Study Start: September 30, 2018
• Primary Completion: September 30, 2019
• Study Completion: September 30, 2019
• Last Updated: December 5, 2018

Record last verified: 2018-12

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)