Transcript Slide 1

T1D and Exercise
Theresa Albright-Fischer,
Amy Mellang, RN, CDE
1. Review energy utilization during exercise
and the hormones involved
2. Review of exercise guidelines
3. Recommended adjustments to insulin
and/or carb intake
4. Discussion of practical applications
Why Exercise?
Lowers BG levels
Feel better
Maintain healthy weight
Increase insulin
• Improve BP and HR
• Keep blood fats normal
• May help maintain normal
blood flow to feet later in
• Reduce some types of
cancer, heart disease,
low back pain,
osteoarthritis and
• Reduction in insulin from
regular exercise is about
General exercise recommendations
• Young children and adolescents (5-17)
– 60 minutes of moderate of moderate to
vigorous physical activity daily 1
• Adults (18-64)
– At least 150 minutes a week of
moderate to vigorous exercise in bouts
of 10 minutes or more1
• ADA -if planning to begin a moderate to high
intensity exercise program 4
Undergo screening with your PCP if– >35
– >25 and >15 years duration with T1D or have
risk factors for CAD, PAD/PVD or autonomic
– Hx of proliferative retinopathy
(some activities can lead to detached retina or
retinal hemorrhage)
Peripheral Neuropathy 3
• Should stay away from– treadmill, prolonged walking, jogging,
step exercises
• Swimming, biking, rowing, chair and arm
exercises, other non-weight bearing
exercises are recommended
Fueling exercise- the 3 players
• The readily available fuel in your blood
– Depending on the level, glucose can be
depleted in about 4 minutes with
strenuous exercise, compared to 30
minutes at rest 2
• Stored glucose in the liver and muscles
that can be released into the blood stream
as fuel
– Even the liver’s glycogen stores can be
depleted after 20-30 minutes of very
strenuous exercise 2
• The body’s largest fuel reserve
– Fat (stored energy) supplies are about
2,000 times as large as glucose stores
and are nearly impossible to deplete
even in a thin person 2
• Insulin
– Causes cells in the liver, skeletal
muscles, and fat tissue to absorb
glucose from the blood
– Insulin stops the use of fat as an energy
source by inhibiting the release of
• Glucagon
– Hormone that stimulates your liver to
release stored glucose into your
bloodstream when your blood glucose
levels are too low
• Catecholamines and stress hormones
– Released into the blood during times of
physical or emotional stress
• Epinephrine (which used to be called
• Cortisol
Without diabetes
• During exercise, insulin levels decrease
and glucagon increases 2
– This helps prevent low blood sugars
from too much insulin
– Tells the liver to make and release new
glucose and allows more fat to be
released from fat cells as fuel
With T1D
• Low insulin 2
– Causes less glucose to enter muscles,
more release from fat stores and liver
– Results in high or rising blood sugars
– Poor performance, possible ketosis
• Ideal insulin 2
– Causes glucose to enter muscles
– Glycogen and fat are released as fuel
– Results in level blood sugars and
optimal performance
• High insulin levels 2
– Cause more glucose to enter muscles
– Less release from glycogen and fat
– Low or falling blood sugars resulting in
poor performance and likely
Aerobic vs anaerobic exercise
• Aerobic- relatively low to moderate
intensity activities requiring oxygen to
generate energy needed for longer periods
(60-85% of maximum heart rate)
– Activities that are continuous and
performed for at least 10-15 minutesSwimming, jogging, biking, rowing,
walking, cross country skiing
• Activities that are performed in short
bursts lasting seconds to 2 minutes
– sprinting, weight lifting, softball, golf
• The oxygen utilized during aerobic activity
allows more fat (fatty acids) to be used for
• Anaerobic activity exclusively uses
glucose (and glycogen) as a fuel in the
absence of oxygen.
• Catecholamine and cortisol are often
present with anaerobic activity.
– These hormones raise blood sugars.
Side Note:
Competitive Exercise
• Very intense or
competitive exercise
– Releases counter
regulatory (stress)
hormones that
raise the BG level
• Avoid worrying about high BG
right after activity, may want to
wait 1-2 hours and check
• Start with a normal BG, may
need to take a bolus of insulin
afterwards to lessen the spike*
*If you notice your BG always rises a
certain amount with certain activities,
you may want to consider giving ½ a
correction bolus before
Side Note:
Using this to your advantage
• During longer periods
of exercise using a
burst of anaerobic
activity during aerobic
• 10-20 second bursts
of intense activity
(anaerobic) appear to
cause enough release
of stress hormones to
lessen risk of lows 1
– Might be a good thing?
• Indicate a lack of insulin and the need for
more 1,2,3,4,5,6
– Exercise now will only burn more fat and
produce more ketones
– Don’t exercise when BG’s over 250 and
ketones are present
– If BG’s >300 (>400 for kids), but no ketones,
test within 5-10 minutes of starting. If BG is
dropping, continue, if not, stop!
Helpful Tips
• Activities that combine anaerobic and
aerobic tend to have a moderating effect
on BG level.
• If resistance exercise is performed before
aerobic exercise, the drop in BG may be
moderated, compared to the reverse 5,7
Helpful Tips
• New to the exercise or untrained? 2
– You may need as much as 25% more
glucose than when you are trained
– Training causes muscles to store more
glycogen to be ready with fuel next time
– With training, large glycogen stores
seem to reduce glucose fluctuations
New activities
– May require more carb intake and less
insulin especially if it lasts more than 4590 minutes
– A larger fall in glucose will occur for
several hours after as glycogen stores
are built up in these untrained muscles
– Check BG’s often and watch out for late
BG increase with activity?
• Without enough insulin present 2
– The increased glucose released by the
liver cannot get inside exercising muscle
– So BG rises in the blood stream
• Check BG’s OFTEN,
before, during and
after 1,2,3,4,5,6
• Even better, if you
have a CGM unit,
wear it,
– but remember CGM is
delayed (10-20 minutes)
set your low alert higher
(for instance 90-110)
• Talk to your doctor
about your target BG
rate before exercise
• Eat carbs if BG’s are
<100 mg/dL before
starting 3
Safety considerations
• Remember BG’s may continue to fall
for many hours after as glycogen
stores are replenished- especially with
new exercise/activity 1,2,3,5,6
– Children are especially prone to more
variability in BG levels. 4
– Hormones of puberty can contribute to
difficulty controlling BG’s. 4
CSII- Pumps
• For strenuous exercise lasting >60min or moderate
exercise lasting >90 min a basal reduction will probably
be needed 2
– Temp basal reductions are not that helpful for
activities of <1 hr 7
– Start your basal reduction before exercise starts (1-2
– After long, intense periods of exercise, bolus basal
and bolus rates may need to be reduced for 24+
• Avoid exercise in the 2 hour window after
rapid acting insulin injection to avoid lows 1
– Unless meal bolus was reduced to
help compensate
Intensity of exercise
30 minutes
60 minutes
Mild (25% of maximal capacity)
Moderate (50% of maximal capacity)
Heavy (75% of maximal capacity)
• Pumps should never be stopped for longer
than 60-90 minutes to avoid ketosis and
BG spike after 2
– Basal can be reduced by 20% for
moderate, and 50% for strenuous
– Remember insulin can only be lowered
so far because some is always needed*
* In children, it may be best to skip a meal bolus entirely to prevent lows
Carb intake
• If insulin adjustments are not made
anticipating exercise, carbs can be
consumed to compensate (without carb
bolus) 1,2,5
– Fast carbs are good for raising low BG’s-glucose
tablets, dried fruit, Gatorade or Power Ade
– Slow carbs help prevent BG drop during longer
periods of activity- PowerBars, oatmeal, muesli, fruit,
Carb Choices
• Rapidly absorbed carbs such as milk or
juice are good for short term activities
• For longer activities, consider crackers or
• Snacks that include protein or fat keep the
blood sugar up the longest
• Needed carb intake during exercise
depends on weight, exercise intensity and
duration of exercise 1,2,5
Other considerations
• Ideally, your BG’s should be in good reasonably
good control before starting exercise
• Activity should include warm up and cool down
• Start slowly, increase duration and intensity over
time. Assess your response, and adjust
• Carry fast acting glucose in case of lows, and more
complex carbs (crackers and cheese) to stabilize
BG after a low
• Remember, after a low, activity should not be
resumed for >10 minutes, or longer, until the
episode resolves- coaches should be aware of this!
Considerations continued• Wear a medic alert noting insulin use and an
emergency contact- tell people your plan if
exercising alone
• Maintain good hydration (early and often)
• Use caution with injection sites (avoid near
contracting muscles) to avoid accelerating
insulin absorption (abdomen usually best)
• Wear proper footwear
Experience is the Best Teacher
• Keep good records to plan for needed
insulin changes and added food
Putting research into practice:
Depends on duration and intensity
• General recommendations- 30-60 grams per
hour or 15 grams every 30 minutes of activity
• Guideline for endurance athletes training from
1-3 hrs per day ranges from 6-10 grams of CHO
per kg body wt. (100lb= 270- 450 gm CHO)
Research into practice:
what works for me!
• If workout is <1 hour no adjustments
needed and check BG after. Always have
quick acting carb with me. ALWAYS!!!
• BG between 150-180 at the start of long
training (2-4 hours) then I don’t have to eat
for an hour and reduce basal to 50%
What works for me!
• 1 package of fruit snacks (19 gm) every 30
minutes after the first hour
• After 2 hours will substitute 15 gram
granola bar for fruit snacks and increase
my temporary basal to 70 %
Depends on type of exercise
• Biking- complex carbohydrate needed
(Granola bars, crackers, protein bars)
Hiking or walking15gm CHO every 30 minutes
No reduction in basal
• Running- simple carbs needed
(fruit snacks, sports drink, shot blocks, jelly beans)
• Rollerblading- same as
running, simple CHO 15 gm
every 30 minutes after the
first hour,
reduce basal to 50%
• Weight lifting or
significant BG rise
post exercise. Will
bolus according to
and watch for lows
later in the day
Balancing carb intake w/ insulin
• 30-60 minutes after exercise, muscle
tissue is able to take up glucose w/out
assistance from insulin
• may not be necessary to use the usual
amount of insulin to "cover" the carbs
Post exercise:
Carbs after exercise
• Serves to replenish glycogen
• Within 30 minutes of completing practice
or competition 1-1.5 g per kg (100lb= 4570 gm CHO)
• Repeat every 2 hours for up to 6 hrs post
exercise to replenish reserves
• Replace glycogen stores to reduce risk of
post exercise hypoglycemia later in the
day following a hard work out
Post Exercise continued:
• After exercise: recovery snack that
contains both carb and protein is an ideal
mixture that helps prevent muscle
breakdown and stimulate repair after
exercise. A popular and effective recovery
snack used by many athletes is 1 cup of
nonfat chocolate milk - 26 grams of carb
and 9 grams of protein
Drink, drink, drink!!!
• Proper hydration allows an athlete to last 33%
longer compared to an athlete who doesn't drink
during workouts
• If event or activity >1 hr, a beverage containing
6-8% carbs is recommended to help maintain
BG during activity. Original Gatorade is 6% and
Powerade is 8%.
• Rehydrating after activity: 16-24 oz of fluid for
every lb of body wt lost during exercise.
Good resources
Diabetic Athlete's Handbook: Your Guide to Peak Performance
– Sheri Colberg has a PhD in exercise physiology, is a Diabetes Health board member, and is
an athlete with diabetes
– Insulindependence is a leading authority in exercise and recreation for people living with
diabetes. Their mission- uniting, expanding and supporting the active diabetes community.
– Global sports organization changing the lives of people with diabetes around the world
through racing, research, international outreach and philanthropic initiatives in developing
– JDRF on line community
Pumping Insulin: Everything you need for success on an Insulin Pump
– John Walsh, PA and Ruth Roberts, MA. A comprehensive guide to getting the most out of
your insulin pump and CGM
An instruction manual for families on the management of diabetes –
– Peter Chase MD, An instruction manual for families on the management of diabetes
Peters A, Laffel L; Type 1 Diabetes Sourcebook, 2013, 249-275
Walsh J, Roberts R; Pumping Insulin, 5th edition, 2012, 239-258
ADA; Diabetes Mellitus and Exercise, Diabetes Care, vol 25, supplement
1, January 2002, s64-s68. Updated March 2010
Fowler M; Diabetes Treatment, Part 1: Diet and Exercise, Clinical
Diabetes, Vol 25, No 3, 2007, 105-109
Guyton Hornsby W, Chetlin R; Management of Competitive Athletes with
Diabetes, Diabetes Spectrum, vol 18, No 2, 2005, 102-107
Chase P; An instruction manual for families on the management of
diabetes, 11th edition, 2012, 137-152
Schneier G; Think Like a Pancreas, 2011, 54-55,
Kain D, AADE in Practice, "Fueling the Athlete with Diabetes", November
2013, p 16-21. Writer is an MA, RD, LD, CDE