15. EXCEL FILE TO CALCULATE AND VISUALIZE FATS VS CARBS OXIDATION RATES FROM METABOLIC CHART DATA

In the last posts we saw:

• the relationship between fuels utilization (fats vs carbs) and exercise intensity (read more here).

• the Knowledgeiswatt spreadsheet (designed by me and Jeff Rothschild PhD) to estimate fuels utilization on the field. You just have to enter power output and duration of a given cycling effort and it returns energy expenditure and carbs consumption (you can download the file here).

While very useful to understand basic principles behind fuels utilization, the spreadsheet can’t be 100% accurate as we can’t measure on the field two parameters necessary to know the exact grams of carbs and fats used:

1. Respiratory Exchange Ratio (RER), the proportion of carbs vs fats used to produce mechanical power

2. Gross Efficiency (GE), how much of the total energy expenditure is converted into mechanical power.

So, how to calculate 100% accurately carbs and fats oxidation rates at different intensity? The only solution is performing an incremental step test) with collection of gas expired through a metabolic chart, and then apply chemistry-based calculation. If you have data (or want to have data) from such a lab-test, we put together for you an easy-to-use spreadsheet to accurately calculate and visualise fats and carbs oxidation rates at different exercise intensity!

Download it here below!