Fueling Insights calculates the fueling contribution of fat and carbohydrates when cycling, allowing athletes to optimize their training and racing nutrition.
Beta Process
Currently, Fueling Insights is not available to the general public. TrainingPeaks Coaches who have signed up for the Beta will receive access on a rolling basis. If you would like to sign up for the Closed Beta but haven't yet, you can sign up here.
If you're a coach who's signed up for the Beta, watch out for an email to access the feature in your inbox (and make sure to check your junk/spam folder).
What is Substrate Utilization?
Substrate utilization refers to how the body uses different energy sources—mainly carbohydrates and fats—during exercise.
- Carbohydrates (Glycogen): Stored in muscles and the liver, glycogen is the body's quick energy source, which it increasingly draws upon as exercise intensity increases. Glycogen stores are limited and (for most people) can’t be fully replaced while exercising, which contributes to fatigue and a drop in sustainable exercise intensity.
- Fats: Fat is a more abundant energy source than carbohydrates in the body but takes longer to convert into energy than carbohydrates. The body burns more fat when exercise intensity is low. Training the body to burn fat efficiently saves glycogen stores for high-intensity efforts.
By training the body to use both energy sources effectively, endurance and overall performance in cycling improves.
What Does Fueling Insights Require?
TrainingPeaks requires three things to calculate substrate utilization:
- A training file with power data*.
- Weight.
- Category.
*At this time, subtraction utilization is only available for cycling workouts with power meter data.
How Does Substrate Utilization Work?
- An athlete uploads a training file with power meter data.
- Click the workout on the TrainingPeaks calendar.
- The Quick View appears.
- Scroll down - Fueling Insights appears on the left side.
- Choose the athlete’s Category.
- Enter the athlete’s weight (the last entered weight in TrainingPeaks will automatically populate).
- Click ‘Calculate.’
- Substrate Utilization details populate.
What Do the Numbers Mean?
- Carbohydrate Use (g/hr) - Average grams of carbohydrate burned per hour for ride duration.
- Total Carbohydrate (g) - Total carbohydrates burned during the entire ride.
- Calories from Carbohydrates (kcal) - Calories burned from carbohydrates during the entire ride. Each gram of carbohydrate is 4 kcal.
- Fat Use (g/hr) - Average grams of fat burned per hour for the entire ride.
- Total Fats (g) - Total fat burned during the entire ride.
- Calories from Fat (kcal) - Calories burned from fats during the entire ride. Each gram of fat is 9 kcal.
- Fat/Carbohydrate Ratio - Percentage of the energy from the ride derived from fat; percentage of energy from the ride derived from carbohydrate.
How Should I Use the Numbers?
Fueling Insights provides actionable information on an athlete's nutrition demands post-workout, which can inform fueling decisions before, during, and after training for future workouts.
Given differences in workout fueling demands, athlete goals, and exercise nutrition approaches, we cannot provide individualized fueling guidelines.
FAQS
What is Substrate Utilization Based On?
Fueling Insights was developed in conjunction with the research of Iñigo San Millán, a prominent exercise physiologist known for his expertise in endurance sports.
What Do the Categories Mean?
Fueling Insight Categories are self-selected performance levels within cycling:
- World Class- World-class professionals competing at the highest level (e.g., Olympics, Tour De France, etc).
- Elite - National-level elite and professional athletes competing at a very high competitive level.
- Master’s Elite - Former national level and professional athletes who continue to compete at a very high level.
- Competitive - Age group competitive athletes who participate in competitive events with a focus on performance.
- Enthusiast - Athletes who are relatively new to training or participate in events with the primary focus of completing events.
Do You Plan to Add to This Feature?
Yes, we’re planning further iterations with additional functionality.
Can I make a suggestion?
We encourage it! Please submit your feedback here.