Carbohydrate Supplements for Gastrointestinal Function During Running

Overseen By Patrick Wilson

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Old Dominion University

Disqualifiers: Cardiovascular disease, Metabolic disorder, others

Compensation: Varies

Number of Visits: 2

4 Participants Needed

Trial Summary

What is the purpose of this trial?

Several previous studies have shown that repeatedly ingesting carbohydrate supplements during exercise training sessions, over a period of days and weeks, can gradually increase carbohydrate oxidation and reduce gut discomfort during exercise. However, repeatedly ingesting large amounts of carbohydrate during training sessions can be burdensome and can cause gut distress. Thus, it would be advantageous if the same long-term benefits could be realized from consuming these carbohydrate supplements at rest instead of specifically during training sessions. Therefore, the goal of this study is to examine whether repeatedly ingesting a carbohydrate-rich beverage at rest over a 5-day period alters metabolism and gut symptoms while ingesting carbohydrate during exercise.

Do I have to stop taking my current medications for this trial?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the carbohydrate beverage treatment for gastrointestinal function during running?

Research shows that carbohydrate sports drinks can improve endurance performance compared to non-caloric controls, but they may also increase gastrointestinal discomfort. While carbohydrate intake during exercise can theoretically enhance performance, the benefits are not always clear, and some studies report no significant performance differences between carbohydrate drinks and water. ^{1 2 3 4 5}

Is it safe to use carbohydrate supplements during running?

Carbohydrate supplements, like sports drinks and gels, are generally considered safe for use by athletes, but they can cause gastrointestinal discomfort such as nausea and cramps in some individuals during intense exercise. ^{1 2 5 6 7}

How does the carbohydrate supplement treatment for gastrointestinal function during running differ from other treatments?

The carbohydrate supplement treatment is unique because it focuses on using carbohydrate intake to potentially improve gastrointestinal function and performance during running, unlike other treatments that may not specifically target carbohydrate consumption. This approach is novel as it investigates the balance between carbohydrate concentration and its effects on gastric emptying and intestinal absorption, which are not typically addressed by standard hydration or energy supplements. ^{1 2 3 4 8}

Research Team

Patrick Wilson, PhD

Principal Investigator

Old Dominion University

Eligibility Criteria

This trial is for distance runners who've done a run over 60 minutes in the past month, are running at least 15 miles weekly, and have finished a marathon in the last year. It's not for those with allergies to beverage ingredients, cardiovascular or metabolic disorders, or who experience symptoms like shortness of breath or chest pain with exercise.

Inclusion Criteria

Have completed one or more marathons within the past year

Be currently running ≥15 miles per week

Have completed at least one run >60 minutes over the past month

Exclusion Criteria

I experience symptoms like shortness of breath, dizziness, or chest pain with exercise.

I have a heart condition or a metabolic disorder.

Allergies/intolerances to any of the ingredients in the beverages

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Baseline Assessment

Participants undergo baseline assessments including a 60-minute run and collection of expired air samples for hydrogen levels, respiratory gases, and gastrointestinal symptom ratings

1 day

1 visit (in-person)

Intervention

Participants ingest a carbohydrate-rich beverage or placebo beverage for 5 days

5 days

Post-Intervention Assessment

Participants undergo post-intervention assessments including a 60-minute run and collection of expired air samples for hydrogen levels, respiratory gases, and gastrointestinal symptom ratings

1 day

1 visit (in-person)

Follow-up

Participants are monitored for any delayed effects or adverse events after the intervention

1-2 weeks

Treatment Details

Interventions

• Carbohydrate Beverage
• Placebo Beverage

Trial Overview The study tests if drinking a carbohydrate-rich beverage while resting (not during training) over five days can change metabolism and reduce gut issues when carbs are consumed during exercise. Participants will compare effects of this drink against a placebo.

Participant Groups

Group I: Carbohydrate Beverage Experimental Treatment 1 Intervention

A glucose-fructose beverage mixture supplying 100 grams of carbohydrate per day for 5 days

Group II: Placebo Beverage Placebo Group 1 Intervention

An artificially-sweetened beverage containing aspartame

Who Is Running the Clinical Trial?

Old Dominion University

Lead Sponsor

Trials

25

Recruited

15,500+

Findings from Research

In a study of 18 highly-trained runners, consuming a flavored placebo drink led to a 0.9% improvement in half marathon performance compared to the first race, indicating that hydration may play a key role in endurance performance.

The use of a carbohydrate gel did not significantly enhance performance and was associated with gastrointestinal discomfort in some runners, suggesting that while carbohydrate intake during exercise is important, the type and method of consumption may need further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of carbohydrate intake on half-marathon performance of well-trained runners. Burke, LM., Wood, C., Pyne, DB., et al.[2019]

In a study involving 98 well-trained runners, the use of carbohydrate-containing sports drinks resulted in a higher incidence of gastrointestinal (GI) complaints compared to water, with significant increases in flatulence and reflux symptoms.

Despite the higher GI complaints, there were no significant differences in running performance among the three drinks tested (water, sports drink, and sports drink with caffeine), indicating that sports drinks do not enhance performance over water during an 18-km run.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of two sports drinks and water on GI complaints and performance during an 18-km run. van Nieuwenhoven, MA., Brouns, F., Kovacs, EM.[2022]

In a study with five participants, lowering the carbohydrate concentration in a sports drink from 6% to 3% did not improve gastric emptying, intestinal absorption, or performance during a cycling time trial.

While total solute absorption and plasma glucose levels were higher with the 6% carbohydrate drink, reducing the carbohydrate concentration led to decreased absorption without enhancing performance, indicating that a higher carbohydrate concentration may be more beneficial for endurance activities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gastric emptying and intestinal absorption of a low-carbohydrate sport drink during exercise. Rogers, J., Summers, RW., Lambert, GP.[2019]

High-intensity shuttle running (LIST) significantly slows gastric emptying of both carbohydrate-free and carbohydrate-electrolyte drinks compared to walking exercise, indicating that exercise intensity affects how quickly the stomach processes fluids.

During variable-intensity running, carbohydrate-electrolyte drinks empty from the stomach at a similar rate as carbohydrate-free drinks, suggesting that hydration strategies can be flexible without compromising gastric emptying.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of intermittent high-intensity running on gastric emptying of fluids in man. Leiper, JB., Nicholas, CW., Ali, A., et al.[2019]

In a study involving 12 well-trained male cyclists, carbohydrate bars were found to significantly reduce peak power output and increase gastrointestinal discomfort compared to gels, indicating they may be less effective for endurance performance.

While drinks and gels showed similar performance outcomes, carbohydrate bars led to higher levels of nausea and perceived exertion, suggesting they are not the best choice for athletes seeking optimal energy sources during intense exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance. Guillochon, M., Rowlands, DS.[2017]

Carbohydrate supplementation significantly improved exercise performance in trained male cyclists, particularly during submaximal exercise followed by a time trial, reducing exercise time by an average of 0.9 minutes compared to controls.

The most effective carbohydrate concentration for enhancing performance was found to be between 6% and 8%, leading to increased mean power output during prolonged exercise lasting over 90 minutes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials. Pöchmüller, M., Schwingshackl, L., Colombani, PC., et al.[2018]

Almost half of the 600 Polish professional athletes surveyed reported using dietary supplements, with isotonic drinks being the most popular choice among them, consumed by 75.4% of athletes.

Despite the widespread use of supplements, there appears to be a lack of awareness among athletes regarding the effectiveness and safety of these performance-enhancing aids, as indicated by the varying rates of usage and the low frequency of creatine consumption.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prevalence of the use of effective ergogenic aids among professional athletes. Frączek, B., Warzecha, M., Tyrała, F., et al.[2022]

Consuming a larger volume of carbohydrate sports drink (200 mL every 20 minutes) during prolonged running significantly increased carbohydrate oxidation rates by 23% compared to a smaller volume (50 mL every 5 minutes).

Both drinking patterns did not lead to significant gastrointestinal discomfort, indicating that athletes can choose either method without worrying about severe GI issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sports Drink Intake Pattern Affects Exogenous Carbohydrate Oxidation during Running. Mears, SA., Boxer, B., Sheldon, D., et al.[2021]

References

1. United States pubmed.ncbi.nlm.nih.gov

Effect of carbohydrate intake on half-marathon performance of well-trained runners. [2019]

2. Germany pubmed.ncbi.nlm.nih.gov

The effect of two sports drinks and water on GI complaints and performance during an 18-km run. [2022]

3. United States pubmed.ncbi.nlm.nih.gov

Gastric emptying and intestinal absorption of a low-carbohydrate sport drink during exercise. [2019]

4. United States pubmed.ncbi.nlm.nih.gov

The effect of intermittent high-intensity running on gastric emptying of fluids in man. [2019]

5. United States pubmed.ncbi.nlm.nih.gov

Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance. [2017]

6. United States pubmed.ncbi.nlm.nih.gov

A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials. [2018]

7. Poland pubmed.ncbi.nlm.nih.gov

Prevalence of the use of effective ergogenic aids among professional athletes. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Sports Drink Intake Pattern Affects Exogenous Carbohydrate Oxidation during Running. [2021]