T1D and ExerciseT1D and Exercise

Theresa Albright-Fischer, RN, CDE

Amy Mellang, RN, CDE pending

Objectives

1. Review energy utilization during exercise and the hormones involved

2. Review of exercise guidelines3. Recommended adjustments to insulin

and/or carb intake4. Discussion of practical applications

Why Exercise?Why Exercise? 1,61,6

• Lowers BG levels• Feel better• Maintain healthy weight• Increase insulin

sensitivity• Improve BP and HR• Keep blood fats normal• May help maintain normal

blood flow to feet later in life

• Reduce some types of cancer, heart disease, low back pain, osteoarthritis and osteoporosis

• Reduction in insulin from regular exercise is about 6-15%

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

Precautions

• 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 neuropathy.

– 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 playersGlucose

• The readily available fuel in your blood stream– Depending on the level, glucose can be

depleted in about 4 minutes with strenuous exercise, compared to 30 minutes at rest 2

Glycogen

• 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

Fat

• 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

HormonesHormones• 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

• 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 adrenalin)

• Cortisol

Without diabetesWithout 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 T1DWith T1D• Low insulin 2

– Causes less glucose to enter muscles, more release from fat stores and liver glycogen

– 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 normally

– Results in level blood sugars and optimal performance

• High insulin levels 2

– Cause more glucose to enter muscles

– Less release from glycogen and fat stores

– Low or falling blood sugars resulting in poor performance and likely hypoglycemia

Aerobic vs anaerobic Aerobic vs anaerobic exerciseexercise

• 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 minutes- Swimming, jogging, biking, rowing, walking, cross country skiing

Anaerobic

• 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 fuel

• 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:Side Note:

Competitive ExerciseCompetitive Exercise• Very intense or

competitive exercise 1,6

– Releases counter regulatory (stress) hormones that raise the BG level 7

• Avoid worrying about high BG right after activity, may want to wait 1-2 hours and check again

• 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:Side Note:

Using this to your Using this to your advantageadvantage• During longer periods

of exercise using a burst of anaerobic activity during aerobic activity– Might be a good thing?

• 10-20 second bursts of intense activity (anaerobic) appear to cause enough release of stress hormones to lessen risk of lows 1

KetonesKetones• 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 TipsHelpful 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 activitiesNew activities

– May require more carb intake and less insulin especially if it lasts more than 45-90 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 lows

BG increase with activity?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

RecommendationsRecommendations

• 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- PumpsCSII- 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 hours)

– After long, intense periods of exercise, bolus basal and bolus rates may need to be reduced for 24+ hours

• 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) 25% 50%

Moderate (50% of maximal capacity) 50% 75%

Heavy (75% of maximal capacity) 75% ___

• 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 exercise

– 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 6

Carb intakeCarb 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, pasta

Carb Choices 6

• Rapidly absorbed carbs such as milk or juice are good for short term activities

• For longer activities, consider crackers or bread

• 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 considerationsOther considerations 1,2,5,61,2,5,6

• 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:Putting research into practice:CarbohydratesCarbohydrates

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: Research into practice: what works for me!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!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 exerciseDepends on type of exercise

• Biking- complex carbohydrate needed

(Granola bars, crackers, protein bars)

Hiking or walking-

15gm 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 competition= significant BG rise post exercise. Will bolus according to recommendations and watch for lows later in the day

Balancing carb intake w/ Balancing carb intake w/ insulininsulin

• 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 ingested

Post exercise: Post exercise: Carbs after exerciseCarbs after exercise

• Serves to replenish glycogen • Within 30 minutes of completing practice or

competition 1-1.5 g per kg (100lb= 45- 70 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: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 resourcesGood 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

• http://www.insulindependence.org/

– Insulindependence is a leading authority in exercise and recreation for people living with diabetes. Their mission- uniting, expanding and supporting the active diabetes community.

• http://www.teamnovonordisk.com/

– Global sports organization changing the lives of people with diabetes around the world through racing, research, international outreach and philanthropic initiatives in developing countries.

• http://typeonenation.org/all_groups/diabetic_athletes/f/85/p/14317/171770.aspx

– 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

SourcesSources

1. Peters A, Laffel L; Type 1 Diabetes Sourcebook, 2013, 249-275

2. Walsh J, Roberts R; Pumping Insulin, 5th edition, 2012, 239-258

3. ADA; Diabetes Mellitus and Exercise, Diabetes Care, vol 25, supplement 1, January 2002, s64-s68. Updated March 2010

4. Fowler M; Diabetes Treatment, Part 1: Diet and Exercise, Clinical Diabetes, Vol 25, No 3, 2007, 105-109

5. Guyton Hornsby W, Chetlin R; Management of Competitive Athletes with Diabetes, Diabetes Spectrum, vol 18, No 2, 2005, 102-107

6. Chase P; An instruction manual for families on the management of diabetes, 11th edition, 2012, 137-152

7. Schneier G; Think Like a Pancreas, 2011, 54-55,

8. Kain D, AADE in Practice, "Fueling the Athlete with Diabetes", November 2013, p 16-21. Writer is an MA, RD, LD, CDE