been diabetic for 11 years. I have opted for short-acting insulin
before meals, combined with long-acting overnight, for most of that
time. I appreciate the flexibility of activities, timing and food-types
that this regime allows me. It means I fit my diabetes around my life
rather than vice-versa. It also allows the opportunity to exercise in a
variety of ways without diabetes presenting anything more than a
My typical insulin requirements are:
Day time (Humalog):
Breakfast (apple & banana): 2-4u
Lunch (sandwich & crisps): 4u
Dinner (pasta/curry/roast): 8-14u
If I have a pudding, or a particularly large portion for dinner my dosage may increase by up to 50%.
Night time (Humulin I*):
after a typical day of moderate activity: 18-24u
*from time to time I take a small dose of Humalog as well, if my blood sugar is a bit high ie greater than 9 mmol/l.
Height: 6’2”, weight: 14st 8 lb
preferred form of exercise is running, although I also enjoy cycling.
In either case the major concern as a diabetic is the endurance factor
– maintaining blood-glucose at a safe level, and an adequate level for
my energy requirements. The following is with reference to running; as
a rule I find the energy demands from running are up to 50 % greater
than with cycling.
As a simple rule I undertake 3 kinds of running:
a) short runs (4-8 times a month)
b) long training runs (1-3 times a month)
c) very long (event) runs – these are rare
all cases above I try to avoid running less than 2-3 hours after taking
insulin, so that ‘insulin uptake efficiency’ is not a complicating
a) Lasting 20-45 minutes I will generally run quite
quickly (for me! – 8 to 9 minute miles), often off-road and over hilly
terrain. Typically I do not find that over the exercise period low
blood sugar is a concern. Preparation will consist of a check to ensure
my blood sugar is between 7-10 mmol/l, and consumption of a Mars Bar or
approximately 200-250 ml Lucozade. For blood sugars outside of that
range I will adjust my initial glucose intake accordingly, by up to +/-
100%. Although I take ‘emergency’ glucose tablets with me, they are
rarely needed. Upon return my blood sugar is normally 5-9 mmol/l and
the ‘honeymoon’ effect of exercise on my blood sugars will last for
8-12 hours afterwards, meaning I reduce insulin dosage by up to 50%, or
eat up to 50% more.
b) Long training runs would generally
be 1 hour – 1hour 50 minutes. I would typically run more slowly, at
about 10 minute mile pace. Preparation is as for short runs, but
hydration and re-stocking with glucose are further considerations. I
have tried drinking orange juice and water (50/50) en route which
provides excellent salt and water replenishment, but generally needs to
be supplemented with a couple of glucose tablets every 20 minutes.
Alternatively a brief stop after an hour or so and a (330ml?) pouch of
a proprietary energy drink will suffice. Frequently after
such a run the ‘honeymoon’ effect will last for up to 24 hours (in a
diminishing capacity) and for even a substantial meal such as a
baguette and crisps I may not take any insulin at all if eating within
a couple of hours of return. Night time insulin requirements will
generally be reduced by up 50 %.
c) I have run a couple of
half marathons and a full marathon. For such distances, preparation and
management are the same as above, but it is imperative to maintain
hydration and fuel intake for the duration. Hydration is essential and
I plan to experiment with adding sugar to my orange juice / water mix
for a single source of hydration and fuel. Experience so far is based
upon simply extending my management for longer runs, but in practice I
find the body ‘settles’ after an hour or so and while I think hydration
needs decrease as I sweat less, digestion can become harder.
Experiences of having drunk too much lead me to believe that over an
hour, little and often is the best approach for hydration; fuelling
requirements remain the same. Potentially a greater factor than the
distance covered, is the time on your feet. I completed the London
Marathon in 5 hours 18 minutes – no records broken then! But I was
running all the way and on my feet for all that time. My body went way
past anything it had experienced before and ‘hit the wall’ at about 3 ½
hours. Little can be done to address this, what a diabetic can do is
ensure that diabetes doesn’t further complicate matters. Following the
management outlined above, my blood sugar level after the marathon was
11 mmol/l – about right for endurance sport in my view.