HIIT

HIIT can support glucose management, glycogen repackaging, mitochondrial biogenesis, and cardiovascular and muscular endurance.

• Morning versus evening glucose: HIIT may temporarily raise blood glucose when performed early in the day, while later-day or evening HIIT may lower it. 1
• Glycogen and metabolism: HIIT and resistance training can encourage glucose to be stored again as glycogen, increase basal metabolic rate, and raise thermogenesis after a workout. 2
• Mitochondrial biogenesis: HIIT can stimulate the creation of mitochondria in muscle; the discussion also notes that cold exposure can stimulate this process. 3 4
• Workout structure: One example is 20–30-second hard sprints followed by 10 seconds of rest, repeated for 8–12 rounds. The aim is to raise the heart rate toward maximum; the speaker cautions that all-out sprinting can carry injury risk. 5 6
• Hydration: The Galpin equation is body weight in pounds divided by 30, giving the number of ounces to drink every 15 minutes of exercise as a rule of thumb; needs can vary with sweating and hydration status. 7