Coach Brock tests and reviews a crazy product called Fuelstrip.
Since recording this video, Brock has found out that FuelStrips actually measure sweat ammonia levels (that correlate with plasma ammonia levels). Plasma ammonia levels increase when muscle is metabolized for fuel and this occurs in greater amounts as glycogen is depleted.
If he was to test his actual lactate levels, they would begin to rise before these strips change colors as it is an indicator of your body switching to an anaerobic metabolism. FuelStrips indicate the next step – when the body has depleted its glycogen reserves and is now using muscle to fuel its activity.