CarbBurnDataField

Carb Burn — know exactly how you're fueling, in real time. Carb Burn is a cycling data field that estimates how many grams of carbohydrate and fat you're burning every second — straight from your power meter. Stop guessing at your fuel mix: see it live, and pace and eat to match. HOW IT WORKS Using your FTP and (optionally) your LT1 / aerobic threshold, Carb Burn models the classic substrate "crossover" — mostly fat at easy intensities, shifting to carbohydrate as you push harder. It converts power to energy expenditure and splits it into carbs versus fat, second by second, grounded in published exercise-physiology models. WHAT YOU SEE The layout adapts to your data-screen slot: - Small / wide fields: carbs burned (g), carb burn rate (g/h), and carb % — the rate and % roll together on a smooth interval. - Full screen: a rich grid with rolling / lap-average / overall-average for carb g/h, fat g/h and carb %, plus carbs spent, glycogen remaining (g and %), and three key wattages — fat-max, the 50% crossover, and your fueling-equilibrium power. COLOR-CODED PACING The rolling carb readouts change color by power zone: grey well below fat-max, blue around fat-max, green up to the 50% crossover, orange up to the 90%-carb power, and red above. One glance tells you which fuel system you're taxing. FUELING EQUILIBRIUM Set your typical carb intake (default 60 g/h) and Carb Burn shows the power at which your carb burn equals your intake — the pace you can hold without draining glycogen. Below it you're sparing; above it you're depleting. Perfect for pacing long climbs and events. GLYCOGEN GAUGE Enter your body weight and it estimates your glycogen stores, how much you've spent, and how much remains — a live fuel tank for long rides. RECORDS TO YOUR FIT FILE Cumulative carbohydrate and fat (grams) are written into your activity's FIT file — as a graphable time series and as session totals — so you can review your fueling in Garmin Connect and other analysis tools after every ride. SETTINGS - FTP (watts) — required - LT1 / aerobic threshold (watts) — optional; estimated from FTP if left at 0 - Gross efficiency (%) — default 21 - Body weight (kg) — for the glycogen gauge and calorie cross-check - Carb intake (g/h) — sets the fueling-equilibrium power GOOD TO KNOW - Requires a power meter and your FTP to be set. - Add the field to a data screen so it can compute and record. - Carb Burn is a power-based estimate for training and fueling guidance, not a laboratory measurement — individual substrate use varies with diet, training status, sex and genetics. Calibrate the gross-efficiency and thresholds to your own numbers for best accuracy. LEARN MORE The full methodology — every equation, the crossover model, the fat-max and equilibrium derivations, and the peer-reviewed citations — is in the technical white paper: https://github.com/Macrophage87/CarbBurnDataField/blob/main/CarbBurn_WhitePaper.pdf Fuel smarter. Ride longer. Burn on.

Version 1.3 - What's new - Red zone now starts at your FTP. Previously red began near the 90%-carb power, which for most riders sits above FTP, so it rarely appeared. Red now flags efforts above your one-hour power - you'll see it when you'd expect to. Version 1.2.0 Colour zones - Zone colour now comes from the same rolling values the field displays, so the colour never lags the numbers: red at 90 percent or more rolling carb energy, orange at 50 percent or more. - The blue fat-max band is now defined by grams per hour: blue while rolling fat burn is within 5 percent of your modelled peak fat g/h. Green runs from the top of the band to the 50 percent carb crossover; grey sits below the band. - Darker blue and green are used on light backgrounds so the coloured numbers stay readable. FIT recording - The per-second FIT fields now record carb_rate and fat_rate in g/h (the rolling rates shown on screen) instead of cumulative grams, which charts much better in Garmin Connect and intervals.icu. Session totals in grams are unchanged. Display - Larger grid text on big screens such as the Edge 1050.