Hi, I am new to this group and getting ready to go on a hiking vacation with 6 days of hiking. I have a recurring problem that is really sporadic and I can’t quiet figure out what is going on. Hoping someone in the group can shed some light on the subject. Yesterday I went on a hike that started with a long uphill climb. Uphill climbs can be hard but this one should not have been. I am an avid hiker but for some reason yesterday I lost all energy and just dragged up this mountain. Once at the top and going down I was fine. It was like I just quickly ran out of all energy. Checked my levels and sugars were fine. Pump was set for exercise. I continued to snack at intervals along the trail and checked sugars several times. They were always in a safe range and not dropping. We hiked over 13 miles yesterday but those first 5 or 6 miles were very difficult and took a lot longer than they should have. As I said in the beginning it doesn’t always happen. I can hike super hard trails and have no problems sometimes. Other times any kind of uphill climb kicks my butt. Would really like to avoid this on my vacation. Any feedback is welcome. Thank you. Linda
Check your pulse/blood pressure, maybe? Might not be a diabetes thing. Maybe check in with primary care Doc prior to trip.
I’m a backcountry skier, so I go up and down hills. First couple days of the season are always slower. It can take a week to really get ‘my land legs,’ starting the season. I tend to do a practice trip prior to when I really need to perform/show off. I think that the tricky thing about that type of exercise is switching from aerobic to anaerobic, repeatedly, over the course of a day - that alternately lowers and raises my BG. Really does a number on my BG’s. I also think that I get very excited and start pumping adrenaline and so a bunch of endo variables come into effect that I don’t really know about. I have noticed (I think) that when I really, really want to be there and I’m performing really well, my BG’s go through the roof - up over 400. I’ve never understood this, but somehow my body must be supplying me with energy that hurts my numbers. Do you have any experience with anything like this?
Smart.
Always good to remember there can be more than one issue at play.
(That actually is sometimes hard for me to keep in mind !!!)
No I sometimes have trouble keeping my sugars in range on hard hikes. Keep cutting insulin back, sometimes off and then layer in the day they are high.
Do you, perhaps, eat low carb (or recently been eating very low carb)? I do a fair bit of intense exercise, and I also hike/backpack frequently. Especially if I’ve recently transitioned from a moderate carb to low-carb diet, I can definitely “bonk” a lot faster than I’m used to. Uphill hiking, sprinting, and heavy weight lifting are all very efficient at depleting glycogen stored in muscles. If your liver is also relatively starved of glycogen (from eating low-carb), and you aren’t eating a lot of carbs before and during your exercise, it’s pretty easy to hit the wall (of no free blood glucose to fuel muscle work) and quickly.
In my experience, two things to consider: I tend to fuel long-term, intense exercise (hiking in steep terrain definitely fits this bill) with relatively regular carb consumption; if you eat low-carb for a considerable amount of time and are consistent, your body will become very efficient at using fatty acids for fuel when glucose is restricted. As a side note, persistent low blood glucose during and after exercise are pretty good indications to me that I’ve depleted glycogen with whatever activity I was doing. YDMV
It’s also possible you’re tired or coming down with something? A viral infection often hits me a few days before I get “sick” by sapping energy.
I can’t specifically help with this issue, but wanted to say, hi and welcome! I’m glad others have some great wisdom to share. 
I know up to 24 hours after a high or low, I can be very draggy while doing exercise. What you describe sounds similar to me.
I think that is the adrenaline spiking your numbers. I got that when I would do wildland firefighting, first half of the day was lows, then the second half when I got my second wind, I would sometimes be dealing with BS in the 300’s. It was really annoying.