How do you prep for Intense Exercise

Hi… I’ve been doing a lot of hiking and bouldering lately. My wife and I did an intense climb this weekend and about 3/4 of the way up I crashed hard… I had cut my basals by 50% about an hour before then decided to suspend my pump altogether. I think my mistake was eating but then taking a little insulin to cover. I’m sure I had 1-2U IOB. Then after treating and deciding not to go on but to go back down the mountain,my sugar spiked… obviously from an over treatment. I’m really looking for guidance on how to do this. Would love to get your advice.


We hike frequently, in the morning, a few hours after breakfast. I cut my basals usually by 1/2, about 90 minutes before we hit the trail. After just under 1 mile, it’s a steep climb for about 1/2 a mile, which used to get me quite low. I’d have to eat Skittles, wait a bit, suspend the pumpand then continue at a reduced pace (more uphill) I detest having that happen. It sort of ruins our fun hikes, so I try to avoid it by suspending the pump at the start of climb unless my bg is really high, like over 170, in which case I’ll leave it at 50%. It takes a lot of practice to get it all right. Our total route is 6 miles, with about 900 feet of elevation.

I just got a Dexcom yesterday, and given how accurate it is, I suspect our hikes are going to be all that more enjoyable as I’ll get an early warning. I don’t like starting out on the 6 mile hike unless I’m over roughly 130. But I don’t like being over 170, either and rarely am over that, at that time of day.

As far as bolusing for breakfast, I cut that in 1/2 or more. Usually toast/pb, egg & toast, egg/bacon/toast, or one of those and add a little bit of fruit. Protein helps level out the bg’s, along with a BIT of fat.

Skittles work well because they are 1 carb each and don’t melt.

I think that this is going to depend alot on your individual system. Collect data. Try to establish a pattern. But, I will warn you that I find this to be one of the most difficult issues to deal with and have been collecting data for years. I have had very little luck finding a pattern. This is a tricky one. I would advocate trying to not over-react to fluctuations in the system - commit to one basal adjustment and ride that all day, so you can clearly see the effect. Expect to go low and treat. A 50% basal drop might be a place to start, but then ride that all day. Then you will have a better guess the next time around. Your not gonna figure it out in one day.

This is I know :slight_smile: Thanks for the input. Makes a lot of sense. I’m going
to start carrying more gels and clif bloks to aid in rapid recovery from
lows. Glucose tabs are too dry for me, even tho I follow with water.

This is the worst. I have worked and worked at figuring this out. Could take us our whole lives, LOL.

We mix up the “type” of carb when exercising. This is specifically aerobic exercise of a number of hours.

I like protein bars (maybe 20 carbs or so any maybe 10 g protein? more or less? I ignore the “net carb” aspect at least in this regard). I find those are helpful for steadying the BG over a longer period. Half a bar every 20~30 minutes or so based on BG readings. And then faster carbs with us like juice and tabs and no-fat candies so if the BG is dropping faster, we can give it a quick bump.

Sort of like our “basal” carbs and our “bolus” carbs. lol

And all the above suggestions as well (I did not want to imply NOT doing those) like basal reductions and watching IOB and the carb content of meal before the exercise and such.

I think we have a pretty good idea of what to do now. I believe the bottom line is that most people are going to react differently and everybody has their own idea of what “exercise” is and what is “moderate” or “intense”. Very individual. Some years back when we were first figuring out the best approach and did not have a cgm, we would set an alarm for every 30 mins to check BG. (Without an alarm I get distracted easily and find I lose track of time without realizing it.) It was a lot of fingersticks but let us feeling very safe and comfortable and helped us to figure out what would work out best for us. The cgm of course makes this quite a bit easier.


I love this conversation. Been struggling since started my running trainings in January. But I will probably try the protein bar advice today! Gracias :slight_smile:

Yeah… more trial and error… was hoping for a “quick fix” for a change…
know what I mean?

Today was our first hike while being on the Dexcom. What a great experience to glance down at the numbers of the receiver instead of periodically checking on a meter. Too often, when using only a meter, I’d end up low at the first “checkpoint” following a trek up a steep incline. Today, neither one of us on the G5 got low (or high). Now I know why so many Dexcom users raved about their systems while I either had no CGM, or suffered through the unreliability of the Medtronic CGM, which was beyond awful. I urge anyone who has a problem with bg control to consider getting a G5 (or G4) if you can either afford to pay for it outright, have Medicare (for G5), or have insurance that covers most of the cost for you. We now have 3 days each on the G5 and don’t get ANY wacky readings. Usually the G5 is within 6 points of our meter readings. Often, it is exact.

Because I was using the G5, at the peak of our climb I could see the trend indicating I needed to have just a FEW Skittles in order to not drop into a mild hypo on the way down. Essentially, my bg control was the best it’s ever been on our favorite trail, which I’d say we have hiked more than 50 times in the last couple of years. We were high-fiving each other because of how great the G5 allowed us to control our bg’s. Hat’s off to Dexcom! :slight_smile:


Yea, there is no way that I could do what I do, physically, without Dexcom.

1 Like