Adjusting My Insulin for Running


During my failed attempt to run a sub 4 marathon in Tiberias last year, I had decided to run the Tiberias Marathon again this year. This decision, however, did not include a hasty registration for the race but was more of a mental commitment of knowing I’m going to do it.

Although I “officially” started training for the race on September 1st, giving me 4 months (and one week) of training, I did not register for the race until Friday night. I don’t know why, but it seems I am scared of commitment when it comes to races. Or maybe I’m a little superstitious about it.

The truth is that maybe I should be superstitious.

So far my training has gone very well, including a new 10K personal record. I’ve been feeling faster and stronger and until Saturday night was quite certain I would break 4 hours easily this time.

What have been continuously bothering me are the lows I experience while running. So far I have been able to get over most of them and keep running, but Saturday night was different.  I went out for a 19 mile run, the longest I’ve attempted so far during this training season.

I headed out feeling fine with BS level of 122. I ate halva right before starting (that worked well for 10K) and started running. I checked my blood sugar for the first time after 6.5 miles. It was 75. I ate a dried apricot (9g carb) in addition to my halva (14g carb) that I eat every half hour, and continued to run. After 13 miles I started feeling weak and checked my BS again.  It was 47. I ate a dried date (18g carb) and some more halva, but it was too late. I was wiped out.

When I finally got home (I ran 2 more miles at a slow pace) I was tired and frustrated.

I’m two weeks away from a 30K (18.75 miles) race and I’m in the midst of marathon training and I’m experiencing lows more often than I ever have during runs. I would really like to reach a point where checking my BS during a run is only an emergency action and not a regular part of the run itself. I don’t think that lows need to be inevitable parts of long runs.

Since going on the Paleo Diet and drastically reducing the amount of carbohydrates I eat, I have significantly reduced the amount of insulin I take during the day, and I reduced my night time dose of Lantus (long acting insulin) – from 20 units to 18.

I thought that the reduction in carbs would prevent highs (it does) and that the reduction in insulin would keep me from going low. Before going on the Paleo Diet I used 20-40 units a day of Apidra (some days more). Now I use 3-15. I thought this serious reduction in insulin would prevent hypoglycemia.

But it seems that while I run my BS drops dramatically, even on days like Saturday when I didn’t take any short acting insulin (Apidra). So I have decided to try and tackle this problem through reduction of my long acting insulin (Lantus). My first step will be a reduction from 18 to 16 units.

I know this may cause my waking BS levels to go up and I will probably need to take more insulin during the day. But this is a price worth paying if it helps me avoid dangerous lows on runs.

I know some of you pumpers out there may think this is nuts (just suspend or lower your basal while running) but I’m not ready for a pump (yet), and I am sure the pump comes with a whole new set of problems.

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Scott K. Johnson
Scott K. Johnson
11 years ago

Hey Michael, Sorry to hear about how frustrating it has been.  I would like to say that I’m proud of you for continuing to push through it and keep trying new things.  That’s what it’s all about – keep trying until you learn enough about how you respond to things, and that knowledge will help you do what you want to do.  Good luck, and keep running! :-)

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