Hi there !
Since I have done my INSCYD testing in october 2019 I have gain a lot of insights on metabolism during cycling. I find really interesting to follow the carb consumption as a proxy for the load of a workout and a guide to adjust fueling during a long ride or race.
Lately, I decide to give a try to Xert with the idea of testing their Carb:Fat Connect IQ app. I have done a lot of all out efforts recently, so my power curve (to feed their algorithm) is quite accurate. I have downloaded all the activities from Strava to Xert and installed the Carb:Fat CIQ app on my Garmin Edge.
I also installed a CIQ app called Fat/Carbs Combustion Monitor developped by Oleksiy. As input in this app, I put the estimations from Inscyd. To give you an idea, their algorithm gave me this estimation of energy expenditure. Personally, I find it highly plausible. Fatmax was around 170ish watts (MAP around 330ish) burning 0,76 g/min of fat (a bit high though ?)
I am 39 yo, 62 kg, 7,5% fat on a Tanita 4 points impedancemetry weight scale. VO2max consistently measured between 55 and 60 ml/kg in the lab, Garmin/Firstbeat in the same ballpark.
I have made some comparisons beetween the energy expenditure estimates by Xert and « Inscyd via Oleksiy app ». Xert constantly overestimates my fat consumption and underestimates my carb consumption. I take the problem in this side because Xert gave me what I feel like odd numbers. On average the overestimation of fat consumption is +30% by Xert and the biggest issue is the underestimation of carb consumption by a whooping 45%. If I would trust their numbers I would bunk in a race ! I have contacted their support and frankly the communication was bad.
In the end, I will stop my subscription to Xert, as a triathlete I don’t find the value in it since it doesn’t take into account the 2 other sports.
On the other side, I recommend digging your understanding in your exercise metabolism because it’s really interesting.