Dark Chocolate and Exercise Performance in Hypoxia

NCT03945916 | Completed

• 1 other identifier: 189
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 2

Brief Summary

Nitrate supplements (beetroot juice, pure sodium nitrate) have become common among endurance athletes because the ingestion of exogenous nitrate leads to increased levels of nitric oxide (NO) in the body. Increased NO has been shown to have various performance enhancing effects such as increased muscle contractility, increased blood flow through vasodilation, mitochondrial biogenesis, and improved glucose uptake. Supplementation with exogenous forms of nitrate has also been shown to improve cycling performance in the oxygen deprived environment of simulated altitude through increased muscular oxygenation. Further research is emerging that suggests that dark chocolate (DC) may have similar effects through flavonoids, a bioactive micronutrient that increases the synthesis of NO and reduces the rate at which NO is removed from the blood. In addition to performance enhancement, the flavonoids in DC also have anti-inflammatory and antioxidant effects, which could reduce muscle damage after a bout of exercise and increase the rate at which the muscle recovers. The purpose of this research is to investigate the effects of DC on cycling performance and recovery in cyclists at altitude. it is hypothesised that the DC condition will result in superior metabolism during exercise and increase muscular oxygenation, leading to improved performance while enhancing recovery from exercise. Methods: 12 trained cyclists will be randomized to supplement with 160g of DC or an isocaloric placebo per day for 2 weeks in a cross-over study. After the 2-weeks of supplementation participants will attend a lab session in which they will cycle 90 minutes at 60% VO2max followed immediately by a 10km time trial (TT) at a simulated altitude of 1500m (15% O2). Plasma levels of blood glucose and lactate will be measured before, throughout, and after exercise while muscular and cerebral oxygenation will be measured continuously throughout exercise. Recovery of the knee extensors will be assessed before and immediately after exercise as well as 24 and 48 hours later by determining knee extensor strength and muscle pain.

Conditions

Hypoxia

Outcome Measures

Primary Outcomes (1)

• 10 km time trial performance

  cycling exercise performance

  Measured on day 15 of dark chocolate/placebo consumption

Secondary Outcomes (7)

• Glucose

  Change from baseline to 90 minutes of exercise

• Lactate

  Change from baseline to 90 minutes of exercise

• Muscle oxygenation

  Change from baseline to 90 minutes of exercise

• Carbohydrate oxidation

  Change from baseline to 90 minutes of exercise

• Fat oxidation

  Change from baseline to 90 minutes of exercise

Study Arms (2)

Dark chocolate

EXPERIMENTAL

180g/d dark chocolate

Dietary Supplement: Dark chocolate

Placebo

PLACEBO COMPARATOR

180g/d of artificial dark chocolate

Dietary Supplement: Placebo

Interventions

Dark chocolate DIETARY_SUPPLEMENT

180 g/d dark chocolate for 15 days followed by exercise testing

Dark chocolate

Placebo DIETARY_SUPPLEMENT

Placebo: 180 g/d imitation dark chocolate for 15 days followed by exercise testing

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Endurance-trained cyclists

You may not qualify if:

• Regular consumption of dark chocolate

Sponsors & Collaborators

• University of Saskatchewan: lead

Study Sites (2)

University of Regain, Faculty if Kinesiology and Health Sciences

Regina, Saskatchewan, S4S 0A2, Canada

Location

College of Kinesiology, University of Saskatchewan

Saskatoon, Saskatchewan, S7N5B2, Canada

Location

MeSH Terms

Conditions

Hypoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Philip Chilibeck, Ph.D.

  University of Saskatchewan

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: Crossover - dark chocolate vs. placebo

Study Record Dates

• First Submitted: May 6, 2019
• First Posted: May 10, 2019
• Study Start: May 15, 2019
• Primary Completion: August 30, 2019
• Study Completion: October 1, 2019
• Last Updated: June 11, 2020

Record last verified: 2020-06

Locations

CA (2)