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Exercise as it relates to Disease/Aerobic or Resistance for type 1 Diabetics, what is best?

Research BackgroundEdit

Type 1 diabetes is an autoimmune disease where the cells in the pancreas that produce insulin have been destroyed by the immune system. The cause of this is unknown, and at this stage Type 1 diabetes cannot be cured [1] There are several complications for sufferers of Type 1 diabetes, some of these are:

  • Vision loss
  • Kidney problems
  • Depression
  • Anxiety
  • and many more [2]

High levels of physical activity have been linked with fewer and less sever complications for type 1 diabetics. It is reported by type 1 diabetics that the fear of suffering a hypoglycemic (low blood glucose levels) during exercise has prevented participation.[3] One of the causes of hypoglycemia is poor preparation for exercise, both in regards to fitness level, and glucose or insulin levels [4] This highlights the importance of developing an understanding of how diabetics react to different types of exercise. Diabetes Australia recommends exercising to help diabetics improve their diabetes management.[5] For those who suffer from Type 1 diabetes Diabetes Australia recommend's not to participate in exercise if they are unable to control their blood glucose levels, or have ketones present in their blood or urine.[6] There are several studies that examine the effects aerobic exercise has on glucose levels of those with type 1 diabetes, however the idea to examine different types of exercises is a fairly new concept [7] Post exercise hypoglycemic episodes are a risk for people with type 1 diabetes, the American Diabetes Association recommends monitoring glucose levels closely post exercise as well as during.[8] If a specific type of exercise can reduce the risk of post hypoglycemic episodes, while still reaping the benefits of exercise this could increase the number of type 1 diabetics who feel comfortable participating in exercise. This increased participation will reduce the number and severity of side effects Type 1 diabetics suffer from.

The research paper Resistance versus Aerobic Exercise - Acute effects on glycemic in type 1 diabetes was published in Diabetes Care, by the American Diabetes Association. This paper was written on a study which examined the acute impacts of resistance exercise on blood glucose levels during exercise and 24 hours post exercise, compared to aerobic exercise and no exercise [9]

What did the research involve?Edit

12 physically active, non obese, type 1 diabetics participated in the study. All the participants had stable HbA (glycotated hymeagloben) of 7.1 +/- 1%. On separate days, with 5 days between sessions, they either completed 45min of resistance exercise, 45min of aerobic exercise or 45min of no exercise. Plasma glucose was measured during exercise and for 60min after. Interstitial glucose was measured by continuous glucose monitoring (CGM), which measures the blood glucose every few seconds.[10] This was done for 24 hours before exercise and the 24 hours after exercise. The participants were kept unaware of their glucose levels during the study to prevent them changing their behavior based on their glucose levels.

Resistance Training SessionEdit

Three sets of eight repetitions of seven different exercises with 90 seconds rest between sets. This session lasted around 45min.

Aerobic Training SessionEdit

45min of exercise at 60% of the participants VO2 max (how this was calculated was not clear) on a treadmill.

No Exercise SessionEdit

Sitting and resting for 45min

All sessions had a 60min recovery period on completion of the exercise that was monitored.

On the exercise days participants reduced their insulin doses depending on how they were taking insulin. During the study afternoon snacks were prescribed for each day, including the exercise days. Glucose levels were monitored and kept between 5.5 mmol/L and 13.9 mmol/L. Glucose tablets were provided to the participants if necessary to maintain these levels.

ResultsEdit

Type of Exercise During Exercise Post Exercise/Recovery
Resistance Exercise Plasma glucose decreased from 8.4+/- 2.7 mmol/L to 6.8 +/- 2.3 mmol/L No Significant change in glucose levels
Aerobic Exercise Plasma glucose decreased from 9.2 +/- 3.3 mmol/L to 5.8 +/- 2.0 mmol/L Glucose increased 2.2 +/- 0.6 mmol/L
No Exercise No significant changes in plasma glucose No significant changes in glucose

The average interstitial glucose was significantly lower after resistance exercise, compared to aerobic exercise.

From these results we can make the observation that when exercising aerobically blood glucose levels reduce during the exercise, when participating in resistance exercises blood glucose reduces, but not by as much as when exercising aerobically. 60min post aerobic exercise glucose levels increase, however there is no significant change to glucose levels post resistance exercise. This has an impact on what food diabetics consume post exercise, and how long post exercise before they begin to have stable glucose levels.

Key FindingsEdit

  • Resistance exercise lowered blood glucose levels.
  • Aerobic exercise lowered blood glucose levels more than resistance exercises.
  • Within an hour after aerobic exercise blood glucose levels increase
  • There was no significant change to blood glucose levels within an hour post resistance exercise
  • Less carbohydrate supplementation was required during resistance exercise compared to aerobic exercise.
  • It remains unclear if resistance or aerobic exercise is directly beneficial for glycemic control.

Research ConclusionsEdit

From the findings of this study we can conclude that trained individuals with type 1 diabetes may experience more stable glucose levels during and after resistance exercise, compared to aerobic exercise. The results from the study suggest that there needs to be more effective protocols for type 1 diabetics when exercising.

Research ImplicationsEdit

Larger samples sizes need to be examined for a longer period of time before any clear conclusions can be made. The idea that a particular type of exercise can vary blood glucose less during and post exercise is one that has potential to help many who suffer form type 1 diabetes. It is important to remember that each diabetic reacts differently to exercise, depending on their previous conditioning, and to glucose. When participating in exercise it is important for type 1 diabetics to monitor their glucose intake and insulin levels and learn how they react to different stimulus.

Further readingEdit

  1. [1], Diabetes Australia.
  2. [2], Diabetes Australia.
  3. [3], Diabetes Care.
  4. [4], Type 1 Diabetes.
  5. [5], Diabetes Australia.
  6. [6], Diabetes Australia.
  7. [7] Care of Children and Adolescents with type 1 Diabetes.
  8. [8] Care of Children and Adolescents with type 1 Diabetes.
  9. [9], Resistance versus Aerobic Exercise - Acute effects on glycemic in type 1 diabetes
  10. [10] Medtronic - What is a CGM?