On a physiological level, how does your body respond to exercise? Where is it getting its energy (fat or carbohydrates), and is your body using this energy efficiently when you exercise or compete? 

The answers are different for everyone, and yet these questions and others can be answered and analyzed through a process that’s called “metabolic profile testing,” says Seattle strength training coach and metabolic testing specialist Bert Abbott. 

Metabolic profile testing is essentially a “look under the hood” of your body – where it gets its fuel and how efficiently this fuel burns at rest and/or when exercising and training. The results of this testing, Abbott said, are used to establish individualized exercise and nutrition strategies that may give endurance athletes a marked edge in training and competition. 

“Metabolic profile testing provides insight into your efficiency in utilizing fat stores as energy during exercise,” said Abbott, a certified strength and conditioning specialist (CSCS) with RealRehab Sports + Physical Therapy in Seattle. “Information received from these tests can be used to help people improve athletic performance, manage weight, and improve body composition and overall health, enabling us to create exercise and nutrition strategies based specifically on how one’s body burns energy.”  

Metabolic profile testing, Abbott says, has value for people who have gastro-intestinal issues that spike during exercise; an athlete who is hitting a wall when exercising and who’s plateaued performance-wise; or a coach or athlete who wants help in setting exercise zones, especially when training for endurance sports.  

An exercise zone, Abbott says, is the level of intensity at which someone wishes to train and what fuel best supports this level of intensity. A sprinter, for instance, requires quick bursts of energy from carbohydrates, while a distance runner is at her or his best when energy comes from the body’s fat stores. 

“Training the body to burn fat for energy means a marathon runner doesn’t have to slow every 15 minutes to get a hit of carbohydrates from juice,” she said. 

Metabolic testing is relatively straightforward. A client wears a mask that measures the output of carbon dioxide and oxygen in the breath during exercise at different levels of intensity. For example: a slow walk to a fast walk to a jog to a brief run on a treadmill. The levels of the gases change according to how much fat or carbohydrates are being burned.  

The results are analyzed at RealRehab from an exercise perspective, and then are referred to a registered dietician who can help the client dial in the diet changes needed to optimize performance.  

“Most people need a reality check at some point,” Abbott said. “They need to understand how diet directly relates to what their physical goals are.” 

“A triathlete eating a diet of 70 percent carbs and 30 percent fat (assuming some proportion of micronutrients and protein is also part of the diet) is not going to meet their endurance goals,” she added. “They need to switch it up so the body is trained to burn fat.”