Use Exercise to Prevent Activity-Induced Lows
You may potentially be able to prevent, treat, or reverse impending hypoglycemia (low blood glucose) during exercise by some novel means (1). One mechanism is short sprints, while another is to alter the order in which you do different types of exercise.
Sprints: Doing a 10-second sprint either before or immediately after moderate exercise keeps blood glucose levels stable for at least two hours afterwards (2). Actually, this technique works anytime during exercise, but it doesn’t reduce the amount of carbohydrate needed to prevent hypoglycemia during the eight hours following such a sprint (3).
Sprinting will have a limited effect if you have high levels of insulin in your system or a blunted hormonal response. However, having been low beforehand doesn’t appear to diminish your body’s ability to respond to a short sprint by releasing enough glucose-raising hormones like adrenaline to raise blood glucose (4).
It’s also possible to keep your blood glucose higher during exercise by interspersing four-second sprints into an easier workout every two minutes or so (sort of like doing interval training) (5). These effects are due to a greater glucose release by your liver during exercise and less glucose uptake by muscles during exercise and recovery (6).
So, whenever you start to feel low during exercise, trying sprinting as hard as you can for 10 to 30 seconds to induce a greater release of glucose-raising hormones. This works best when you have only a limited amount of insulin circulating in your bloodstream and may not prevent hypoglycemia if you have a lot of injected or pumped insulin on board. When the hormonal effects wear off, though, be careful as you can develop hypoglycemia since sprinting uses up more of your muscle glycogen (stored carbs) that have to be replaced with blood glucose (3).
Exercise Order: Another strategy you can use for preventing exercise-induced lows is related to the order of the types of exercise you do (cardio and resistance training) (1). Blood glucose levels tend to fall more during moderate cardio training and less afterwards compared to resistance training, which causes less of a decline during and more overnight (7).
Doing both activities in one day can be done strategically. If you’re starting out with your blood glucose on the low side, do resistance training first, followed by cardio to keep your glucose higher throughout the first half of your workouts. If you’re starting out higher, begin with cardio training first (assuming it’s moderate and not intense) to lower your blood glucose levels and follow it up with resistance work, which keeps blood glucose stable (8).
Try these techniques today to stay on top of your lows and remain more active. Your body will thank you for it!
1. Yardley JE, Sigal RJ. Exercise strategies for hypoglycemia prevention in individuals with type 1 diabetes. Diabetes spectrum : a publication of the American Diabetes Association 2015;28:32-8.
2. Bussau VA, Ferreira LD, Jones TW, Fournier PA. A 10-s sprint performed prior to moderate-intensity exercise prevents early post-exercise fall in glycaemia in individuals with type 1 diabetes. Diabetologia 2007;50:1815-8.
3. Davey RJ, Bussau VA, Paramalingam N, et al. A 10-s sprint performed after moderate-intensity exercise neither increases nor decreases the glucose requirement to prevent late-onset hypoglycemia in individuals with type 1 diabetes. Diabetes care 2013;36:4163-5.
4. Davey RJ, Paramalingam N, Retterath AJ, et al. Antecedent hypoglycaemia does not diminish the glycaemia-increasing effect and glucoregulatory responses of a 10 s sprint in people with type 1 diabetes. Diabetologia 2014;57:1111-8.
5. Dube MC, Lavoie C, Weisnagel SJ. Glucose or Intermittent High-Intensity Exercise in Glargine/Glulisine Users with T1DM. Med Sci Sports Exerc 2013;45:3-7.
6. Fahey AJ, Paramalingam N, Davey RJ, Davis EA, Jones TW, Fournier PA. The effect of a short sprint on postexercise whole-body glucose production and utilization rates in individuals with type 1 diabetes mellitus. The Journal of clinical endocrinology and metabolism 2012;97:4193-200.
7. Yardley JE, Kenny GP, Perkins BA, et al. Resistance versus aerobic exercise: acute effects on glycemia in type 1 diabetes. Diabetes care 2013;36:537-42.
8. Yardley JE, Kenny GP, Perkins BA, et al. Effects of performing resistance exercise before versus after aerobic exercise on glycemia in type 1 diabetes. Diabetes care 2012;35:669-75.