Hmmm, tough question. I usually "cut" my basal on running days more than I push it up on non-running days. Over the summer, it occurred to me that if I were running 4 days/ week, it would make more sense to have a "running" rate and push it up not to run. I just sort of played it by ear and ate more too. Not always the awesome maneuver, or counterproductive in a way. If you are at 5.0 A1C (very good job!!, "normal"!) you may also be overbasaling a bit?

I had hit 5.0 over the summer but had one hypo (caused by my negligence in managing a "perfect storm", really busy string of days...) where the paramedics found a in irregular heartrate that they never figured out a "problem" but did a bunch of tests. The doc admitted it could just have been being whacked out on insulin causing the "misfire" but we'll never know for sure. I kind of backed off a bit, worked to mellow the control just a shade, like 80-90 instead of 70, A1C has drifted back up to 5.6 but it seems easy to run.

The other thing that happened for me over time is that while I used to turn the basal down to 7%-25% normal while running, after I was running 30-40 miles/ week for a lot of the summer (marathon training...), my basal "cut" went down and I ran the marathon at like 30-70% of the "normal" rate. I dont bother cutting for 3 mile runs at all, as it's only 25-30 minutes. I'd like to think that perhap this means I was "getting in shape" somehow from an endocrinological perspective but I dunno, I haven't really seen that reported anywhere. If you take lengthier than a couple of days off biking, you may not see that and may need to "cut" more aggressively, which can be ok too?