Walking after meals did not reduce blood sugar in the long term

The PhD thesis of Håvard Nygaard shows better regulation of hyperglycemia the next day when exercising after a meal compared to before a meal. However, postprandial exercise for 12 weeks did not improve blood sugar.


MAIN RESULTS:

  1. Regular light physical activity after a meal did not improve blood glucose in the long term in persons with hyperglycemia or at high risk of hyperglycemia.
  2. Moderate exercise within 30 minutes after breakfast decreased glucose excursions during the next day in hyperglycemic individuals. Exercise in the fasting state had no such effect.
  3. In persons with high blood sugar there was a small increase in inflammation following exercise, with no difference between exercise before and after breakfast.

THESIS DEFENCE:

Thesis: Effects of postprandial and fasted exercise on glycemia and markers of inflammation in persons prone to or with diabetes
Candidate: Håvard Nygaard
Time: September 15, 2017 at 13:15
Place: Oslo University Hospital, Rikshospitalet B: Red auditorium 2
Link to university website (in Norwegian)


SUMMARY:

(1) 56 individuals with or at risk of hyperglycemia were randomized to 30 minutes of light exercise within 30 minutes after a meal or a control group. Forty participants completed the study, and the self-reported increase in daily physical activity after 12 weeks was higher in the intervention group. However, there were no change in any glycemic variable and no difference between the two groups after 12 weeks.

(2/3) 12 hyperglycemic individuals completed three different test days: exercise before breakfast, exercise within 30 minutes following breakfast, and no exercise. Exercise after breakfast decreased glucose excursions during the subsequent 22 hours compared to exercise in the fasted state and no exercise. Pooled analysis from the two exercise days showed that the inflammation marker soluble VCAM-1 increased from baseline compared to no exercise, whereas exercise did not influence CRP values.

The participants were instructed to refrain from other physical activity on the test days, and to consume the same meals on all three days. The exercise consisted of one hour uphill walking on a treadmill.


REFERENCES:

(1) Nygaard, H., Grindaker, E., Rønnestad, B. R., Holmboe-Ottesen, G., & Høstmark, A. T. (2017). Long-term effects of daily postprandial physical activity on blood glucose: a randomized controlled trialApplied Physiology, Nutrition, and Metabolism42(4), 430-437.

(2) Nygaard, H., Falch, G. S., Whist, J. E., Hollan, I., Ellefsen, S., Holmboe-Ottesen, G., Rønnestad, B. R., & Høstmark, A. T. (2017). Acute effects of post-absorptive and postprandial moderate exercise on markers of inflammation in hyperglycemic individualsEuropean journal of applied physiology117(4), 787-794.

(3) Nygaard, H., Rønnestad, B. R., Hammarström, D., Holmboe-Ottesen, G., & Høstmark, A. T. (2017). Effects of Exercise in the Fasted and Postprandial State on Interstitial Glucose in Hyperglycemic IndividualsJournal of Sports Science and Medicine16, 254-263.