Returning to Running

I run between 5km and 10km 3 or 4 times a week. I don't drink Lucozade or any other sports drink; just water.

I like my levels to be between 5-8 before running and I try not to run within 3 hours of a bolus shot.

For me, my levels during running either remain the same or increase very slightly: it's rare they will drop. I carry glucotabs in case but I've only needed them during longer runs.

What I do see is increased insulin sensitivity post-run and I'm more likely hypo later in the day or overnight.

If you have got your basal nailed then I really don't think you should be too worried about doing anything differently or chugging down Lucozade as a precaution, especially since your Dexcom will warn you if you're heading low anyway. I was nervous about returning to running post-diagnosis and always gulped down sugar beforehand (and used to be paranoid I was hypo'ing even when I wasn't) but I am lucky in that it's really not been a big deal. If you're worried, I'd just start your first run at a little higher BG than normal to give yourself some buffer.

ElkBond said:

I wouldn't say basal is nailed but its definitely more stable that it has been for a while. I expected the post run sensitivity and I have done some digging and if I keep to some routine (72 hours-ish max between heavy exercise) then that sensitivity will remain. Have you found this?

I am very pleased that water may be sufficient! I really hate cordials or sweet drinks. My only concern is in the past when I used exercise to lower my BG I have dropped rather quickly, which is why I have presumed that water is a no go.

Click to expand...

My own experience is that the post-run sensitivity is fairly short-lived (typically 12-18 hours maximum), but I am sure it's different for everyone and may be much longer for you.

Again, I can only speak from my own experience as to levels not dropping during exercise, but one thought is whether you have typically had any insulin on-board when exercising in the past? That's the only time my levels drop quickly when exercising.

My routine now is to run as soon as I wake up (before my breakfast shot) or to run before dinner. Benefit of this is that I can then eat porridge/berries/coffee with just 1 unit of insulin (cf. 2.5 units when I have not run beforehand) and my dinner doses are also reduced by around 50% after runs (mainly for the longer 10km runs though; not so much for 5km runs unfortunately, although this has decreased very gradually over time).

Yay for running!

Personally I run regularly, anything up to about 15 miles - I race half-marathons. I'm generally good at avoiding hypos while I'm running, but become exceedingly insulin sensitive afterwards and that can last for a couple of days in the case of a hard race of an hour or more. It's not unusual for me to find myself stuck in the car park after a run, unable to get a blood sugar high enough to drive home... so I try to plan around that now.

Check out http://www.runsweet.com

It's a website by the guys at Loughborough Uni who sorted out Steve Redgrave. They are the top experts in sports/exercise and T1 diabetes. It is rammed with useful, practical info, and will also teach you the science of what happens around the different glucose transporters when we exercise - understanding this was huge for me, 'getting' why my body might behave as if I'd just bolused after I ran, when I hadn't taken any extra insulin.

Some headlines:

- There's no such thing as a meaningful 'buffer' from starting a bit high - most of us can only store enough glucose to last a brief period of intense activity, after that you're relying on your cortisol/glycogen system to release more, which may not always be available, especially if you've had a recent hypo or near-hypo and drained your reserves.

- Most of us need to top up with glucose every 20-30 minutes while running to avoid a hypo, but the intensity of the exercise makes a big difference. 'Running' can be anything from a chat-while-you-jog to two hours of threshold, and these have different effects.

- We vary enormously, so experimenting (sensibly) to find out what your own body does around exercise is key. I use a heart rate monitor when I run to get more reliable feedback about how hard I'm working. I know I can sustain an hour of very easy running without extra glucose, but I need to use a medium-sugar sports drink (powerade in my case) and also take a 23g CHO gel every 25-30 minutes when I'm racing.

- Making adjustments to both basal and bolus in the 24 hours after exercise can be as important as what you do while you're actually running.

Replacing what you've used is important for avoiding a cluster of hypos due to draining your glycogen reserves. Whether running high or low, we are less good at storing carbs for later than our type-zero peers. The magic formula is 4:1 CHO to Protein within 30 minutes of finishing exercise. You can estimate calories to work out how much you want to replace, and my own weapon of choice is Nesquik (any chocolate milk works well for the 4:1 ratio). I don't want to lose weight, so if I've been on a 400kcal run then I'll aim to drink at least a half-pint of chocolate milk shortly afterwards to cover most of those losses.

Recently I've made some changes that mean that I'm having fewer bad hypos generally, and interestingly I'm stacking up PBs even though I'm training less than I have in a couple of years. It seems like there's a vicious or virtuous circle of exercise/hypos/performance that is tough when you're going down but if you can nail it then it's all good.

The main hard lesson I've learned is that I have to do the training session I've planned for - it's when I get the buzz and what was supposed to be an easy run turns in to something more intense that I get bitten (because I haven't got the right drink/gels/eaten enough the day before etc).

I find a Libre really useful for training and racing over 10 miles.

Good luck!

@curiouser makes some excellent points and many/all of them hold true for me, personally.

While I definitely don't race, I can run for about 90 minutes (avg. about 9minute miles) before I start to get bored.

As crazy as it sounds, I find that a shorter ~3mile run actually makes it tougher to manage my blood sugar than longer runs that exceed 45-60 minutes. The main reason for that is around depleting glycogen reserves as curiouser mentioned. If I only run 3 miles, my blood sugar will continue to climb for another 15-30 minutes and will usually need an insulin correction to bring back down.

My issues are more with respect to hypers rather than hypos and I only begin to have (small) hypo issues if I exceed 10 miles.

My general approach is to run early in the morning 5:30am-7am when my chances of hypos are lowest. On days I run, I give myself a very small bolus (half a unit) and my normal Levemir dose. On days I don't run, I give myself a 1-1.5 unit bolus in order to combat my morning spikes that mimic dawn phenomenon (although likely from my high protein intake).

The end result is that I get a modest blood sugar rise in the first ~30 minutes of running, and after that my levels begin to fall back down to normal (4-6mmol/l) as stay that way until I exceed 90 minutes of running.