Staying in the Zone: Managing Blood Sugars While Playing Sports

There’s ten seconds on the clock and the game is on the line. You are in the huddle and the coach is drawing up the play for you to take the final shot. There are beads of sweat rolling down your face and your legs begin to feel as light as a feather, the room begins to spin around you, and your hands begin to shake from the inside out. You dread what you have to say to your coach but only you know what you need to do as you say: “Coach I’m out, my blood sugar is low.”

Has T1D ever been an obstacle in the enjoyment of your favorite sport? Have the high and low BGs ever hindered your performance? After experiencing a disheartening moment in the final moments of my high school basketball game where I could not help my team in their time of need, I knew I needed to reassess my diabetes game plan. After that game, I knew it was time to go back to the drawing board to figure out what I could do to keep stable blood sugars during sports. Today, through much trial and error, I am able to enjoy basketball, football, and tennis with relatively stable blood sugars. Here is what my method looks like and some generalized tips to find what works for you!

Find your ideal blood glucose range for exercising 

My optimal range is around 120-180 mg/dL. I found out that when I was too low I was too weak to play which posed a danger as I could pass out. On the flip side, if my sugar rose too high I felt lethargic and felt like I couldn’t play to the best of my ability. 

Figure out your pre-exercise fuel

After experimenting with protein bars/granola bars before exercising, I found that eating a bar with approximately 15g carbohydrates and 10g of protein before my exercise helped to keep my blood sugars the most stable within my desired range. I tried a variety of different bars, logging how they affected my blood sugar during my sport and if I was happy with my performance. After comparing  the different style bars I came up with what worked best for me: Nature Valley and MetRx bars. 

Bolus strategy for your pre-exercise fuel

To stay in range, I need to bolus for about half of the carbs in my pre-exercise snack. Covering for the whole 15g carbs would send me low because of insulin on board, but not covering the bar at all would cause highs during exercise. It is important to be patient during this process as these little tweaks can take some time to figure out what works best for you!

Lows will happen- ALWAYS bring your favorite low snack!

I always have a Capri Sun juice box or apple juice (about 15-20g carbs) with me in case I go low. After treating a low, I always sit out for 15-20 minutes while monitoring my blood glucose (BG) rise on my CGM. Additionally, I keep my CGM low alert around 80-90 mg/dl so I am able to act before I drop severely low as well as keep my alert alarm on high volume so I can hear it while playing. 

Watch out for delayed lows a few hours post-exercise!

After exercising, I often have a delayed low BG about two to three hours later. I usually combat this with a sandwich (30g total carbohydrates) if it’s during the day or if it is late at night then a glass of milk (15g total carbohydrates). I typically give my full insulin amount to cover these snacks/meals post exercise, but your bolus strategy might be different! Remember, insulin sensitivity increases in the hours and days following your exercise, so definitely keep a closer eye on your blood sugar.

Miscellaneous top tips for exercising with diabetes

• Share my CGM data with family and friends
• Make sure I don’t eat too large of a meal prior
• Make sure the people I am playing with know I have T1D
• Bring an additional protein bar with me to keep me fueled for longer if I know I will be playing for a long amount of time 

Practice makes (almost) perfect!

Finding what worked best for me was a difficult process requiring a lot of patience. It can be very discouraging to feel like you prepared yourself to enjoy your sport and then it was ruined by a high or low BG. It can place a strain on your mental health as it is very frustrating. Make sure you talk to your doctors, friends, and family– T1D is a team sport. There are still days where my method doesn’t work 100% for me and my BG drops low or goes high and I have to come out of the game. I think it is important to try and find a system that works for most of the time so that on most days, you can enjoy the sport you always have loved and don’t feel held back by diabetes.

By developing your diligence and patience through these phases of trial and error to figure out your BG stabilization method, these skills will not only translate to the sport you love the most but also your career, hobbies, and other life stressors. Your future self will thank you so keep pushing through!

Editor’s note: This post is not considered medical advice– what works best for one person might not work best for you! Please work with your medical team on any changes to your diabetes management strategies.