1. What is a HIIT Workout

High-intensity interval training (HIIT) is an anaerobic workout that pushes your heart rate above 80% of your max VO2. This is an intense workout that pushes your body to the max for a short period of time and then brings it back down.

2. What Did The Research Show

This study was conducted with subjects who have type 2 diabetes.  One group performed a HIIT workout 1 hour after breakfast and the other group performed a HIIT workout 3 hours after lunch.  The study found glucose spiked in those who did their workout after breakfast and lowered in the group who did their workout after lunch.

3. Research Conclusion

Although the study did not make a specific conclusion as to why these results happened, we can theorize that putting a greater stress on the body first thing in the morning will spike cortisol. Cortisol is a glucocorticoid so you can expect blood sugar to rise as well.