Carbohydrates and Running Performance

Carbohydrates serve as the body's primary energy source during intense exercise, and consuming carbohydrates during exercise has been shown to improve exercise performance. Previous research has shown that the presence of carbohydrates in the mouth activates sweet taste receptors on the tongue, which signal the brain to increase neural activation in areas associated with motor functioning, sensory perception, and reward centers during exercise through this CPR. The primary objective of this intervention is to establish how carbohydrates delivered in different forms (MR versus dissolvable strip (DS)) affect running performance during a 12.8km running TT.

This trial will be a randomized, controlled crossover design in humans. There will be four study visits (see Figure 1 below). The first visit (Baseline Visit/V1) will entail signing informed consent documents, anthropometric measurements, familiarization with the MR and DS, and the exercise protocol. For the three testing visits (V2-V4), subjects will perform a 12.8 km running TT on a motorized treadmill, with the only difference between visits being the form of treatment. Either a carbohydrate MR solution (called CMR), water MR solution as a control (called WMR), or carbohydrate DS (called CDS) will be administered at each visit in a randomized order. Study visits will be separated by at least 5 days, and all visits will take place in the Human Nutrition Lab (HNL) at the University of Georgia in Athens.

Specific Aims:

1. To examine the effect of carbohydrates delivered in different forms on running performance.
2. To examine the effect of carbohydrates delivered in different forms on physiologic measures as well as perceived exertion.

Hypotheses:

1. The investigators hypothesize that the carbohydrate-containing MR and DS will result in faster TT performance compared to a water MR (control).
2. The Investigators hypothesize that the carbohydrate-containing DS and MR will elicit higher HR and blood lactate levels (indicating greater levels of intensity) compared to control without significantly increasing RPE during the running TT.

Eligibility Criteria:
Inclusion Criteria:

* 18-45 years old
* Male or Female
* Normal body mass index (BMI) between 18.0-24.9kg/m2
* All subjects will be endurance-trained athletes who participate in training on a regular basis (≥4 sessions per week for at least 1 hour per session of aerobic/endurance exercise (such as running, cycling, or swimming)
* Women will be tested only during the follicular phase of their menstrual cycle (days 2-9) to control for any fluctuation in hormones
* Individuals aged 35 or older must pass the Physical Activity Readiness Questionnaire (PARQ2)

Exclusion Criteria:

* Anyone eating a low carbohydrate diet (such as The Zone™ Diet or Atkins™ Diet)
* Changes in current exercise program
* Chronic diseases (including but not limited to type II diabetes, hypertension, hypotension, hyperthyroidism, cardiovascular disease, and cancer)
* Medications that could alter metabolic rate or hydration status
* Supplement use other than fish oil or vitamin/mineral supplements
* Nicotine use
* Pregnancy or nursing
* Donation of blood in the 20 days prior to testing
* A failing result on the Physical Activity Readiness Questionnaire (PARQ2) for those aged 35 or older
* Allergy to red food dye FD\&C Red No. 40