What is the Effect of Intense Exercise on Glucose Levels?

One of the really exciting things I've been looking forward to seeing whilst trialing the Abbott Freestyle Libre System, is what my glucose levels do during training. Of course I test regularly when I'm doing blood sugar tests instead whilst at training, but there are only so many of those tests that you can do before your fingers get sore and it doesn't provide you with the information of what's going on in-between times either.

Last night I had a blocks session, for those not familiar with this type of training- starting blocks are the things that sprinters push off from at the start, when they're doing a short sprint race. The action involves crouching down behind the start line and positioning your feet on the foot pads, then when the starter says 'set' you lift your behind in the air and push off the pads, whilst moving your feet as quickly as you can and exploding/ driving forwards down the athletics track. The movement is a lot like an aeroplane taking off (minus the leaving the ground bit). It's an incredibly explosive and high intensity movement, that involves using great forces to put your whole body in motion. What's always surprising about the session is that you never really run far whilst practising blocks, maybe up to 100m, which isn't that far for a longer distance sprinter. But everyone comments on how tiring it is because the exercise is so intense and all consuming.

Using my Abbott Libre Sensor at the Athletics Track

As you can see below on my sensor's glucose level graph, it was a good day to look at the effect of explosive high intensity exercise on glucose levels, because I'm within normal glucose range throughout the day. Training started at 6:30pm last night and it's easily visible in the numbers and in the graph, that my glucose levels rose in preparation for exercise. It then continued to rise as adrenaline started taking effect. But immediately after the session is over about 8:30pm, my glucose levels drop, I think as a result of the intensity and the deficit that burning off the glucose in my glycogen stores has. I then continue to remain steady, eating food at about 9pm and seeing a minimal spike and then glucose levels tail off as my body needs refuelling from the high intensity exercise.

Abbot Freestyle Libre Sensor Results for High Intensity Exercise.