Figure 1: Calorie Expenditure (Per Hour) for Each Exercise Intensity Chosen

• As exercise intensity increases, the number of calories (energy) your body uses increases as does the percentage of carbohydrate (versus fat) used by the body.

Figure 1: Calorie expenditure (per hour) for each exercise intensity chosen

Figure 2: Carbohydrate Utilization (grams/hour) for each exercise intensity chosen

OVERVIEW

We conducted a test to determine your caloric expenditure and your fuel (carbohydrate/fat) usage at various exercise intensities during a 30-minute running session.

Intensity:141 – 180 bpm (77-98% of age-predicted max HR)

Conditions:Air Temp: 75°FHumidity: 34%

CALORIC EXPENDITURE

The mask you wore during exercise allowed us to collect your expired gases and from that calculate your caloric expenditure. The body needs and uses varying amounts of oxygen to burn fat and carbohydrate for energy. As the body uses carbohydrate for energy, the body also produces increasing amounts of carbon dioxide. Through the measurement of these changes in oxygen and carbon dioxide concentrations, we can see how many calories you are a burning. Figure 1 (previous page) displays the heart rates we recorded at the varying speeds of your exercise test as well as the calories you were burning at those intensities. Overall, you used 301 calories during this 30 minute test that ranged from low to moderately-high intensities.

FUEL USEAGE

In addition to estimating caloric expenditure, by collecting your expired gases we were also able to determine the source (carbohydrate vs. fat) of the energy used during your test. At rest and low intensity exercise fat is the major contributor to energy demand. As intensity increases carbohydrate provides increasing contributions to the energy demand. Because carbohydrate stores within your body are limited, it’s important to consume carbohydrate during exercise to help fuel muscles and maintain exercise intensity. Figure 2 (previous page) displays the amount of carbohydrate used by your body at each exercise intensity completed.

HEART RATE RECOVERY

Measurement of how quickly your heart rate recovers, or returns to baseline after exercise, is an indication of your fitness level or training status. Both endurance and strength training improve heart rate recovery. Monitoring how quickly your heart rate returns to baseline after exercise is a good way to monitor your training status throughout the year.

INITIAL HYDRATION ASSESSMENT

Your pre-exercise urine sample indicated that you were hydrated prior to the test. (USG = 1.003). A urine specific gravity <1.020 is indicative of adequate hydration. In the absence of a formal test remember pale urine (like lemonade) is a good indicator of adequate hydration. Dark urine (like apple juice) is a sign of dehydration and clear urine is a sign of over-hydrating.

ADDITIONAL INFORMATION

While replacing fluid loss during physical activity should be one of your nutritional goals, replacing 100% of the calories or 100% of the carbohydrate used is not. While it is important to consume carbohydrate both before and after exercise to ensure your blood, liver, and muscle carbohydrate stores are topped off, your body can only use approximately 60-100 grams of carbohydrate per hour during exercise. To help you understand how much carbohydrate you are consuming from Gatorade we have included the following table: