The Endurance Exercise Principles (i.e. The Guide To Avoid Lows At All Costs)

How To Avoid Going Low During Exercise

Exercise is quite the paradox in diabetes management. On one hand, it provides long-term stabilization and a natural lowering of glucose. On the other, it supplies the most significant swings in glucose levels possible. As outlined in previous posts, depending on the kind of exercise being performed (aerobic vs anaerobic), one can expect different glucose results. Today, I’m exploring a couple of principles that I’ve noticed over the past two years of marathon training and duathlon events. I’m no professional. Just a guy who likes to get his heart rate up every once in awhile, while avoiding the catastrophic low.

1) Explore a temporary basal (that is, if you wear a pump)

This has helped me tremendously in the fight against post workout hypos. Do I still see a drop? Absolutely, yet the intensity of the downslope isn’t as intense. Here’s an important point to keep in mind–if you drop your temporary basal really low, say 10% of normal, your body will have much less insulin on board for subsequent hours, putting you at risk for a high blood sugar post run. In my experience, after a two hour run with a basal rate of 30-40% of normal, while sitting a blood sugar of 100ish, I put a unit or two on board. I would not do that if my blood sugar sat at 60 post run. Trial and error is the key idea. Keep track of what works. Notice trends.

2) Limit the amount of insulin in the system

Exercise is the great amplifier of insulin. Taking a 30 minute run with no insulin on board at a blood sugar of 175, I’ll finish up around 120. Taking a 30 minute run with 3 units of insulin board at a blood sugar of 225, I’ll finish up around 60. Just be aware of insulin levels and how much gas they still have in the tank. I like to check the active insulin amount, found by hitting escape on a Medtronic pump. At the insulin level below, I’d be expecting a low blood sugar upon exercise.

Active Insulin and Exercise For T1D

3) Stick to a fuel plan

Our muscles burn an extraordinary amount of glucose quite quickly, mainly from stored glycogen in muscles, but eventually from the blood. Given our inability to activate the liver’s blood glucose replenishment (aka, lack of glucagon effectiveness), it’s wise to supply the glucose yourself, especially during endurance activity. This is purely an act of the scientific method. Practice makes perfect here. My routine, when out for two hours running or biking, is to fuel up every 30-45 minutes. Running usually demands more fuel, cycling less. I outlined a fuel strategy for marathon training here. Eventually, I would gas up on a Hammer gel, Gu, or homemade creation (dates, agave nectar, and coconut oil paste) every 6 miles. That seemed to sustain me during longer bouts. When out on a 6 mile run, I’ll bring along one of those snacks just in case it’s necessary but not always needed.

==Is that weekend adventure calling your name? Pick up what our team uses when we hit the road, trail, or mountain.==

3 thoughts on “The Endurance Exercise Principles (i.e. The Guide To Avoid Lows At All Costs)

  1. Pingback: 100° Of Blood Sugar (The Absurdities Of Exercise In High Heat and Humidity) | Diabetes Daily Grind | Real Life Diabetes Podcast

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