Week 7

Question 1

What is HIIT?

Answer 1

High intensity interval training

No universal definition however main points include:

Repeated short bursts of high-intensity exercise with low-intensity or rest intervals.

Typically lasts less than 30 minutes.

Time-efficient strategy to achieve similar benefits to endurance training.

Time duration is based on participants fitness

Intensity also depends on the duration of the session

Examples: Sports like football, basketball, and tennis.

Question 2

Adaptations from HIIT?

Answer 2

Improved exercise capacity (VO2 max and endurance performance).

Increased muscle glycogen storage and reduced glycogen breakdown during exercise.

Decreased lactate production while increasing pyruvate dehydrogenase (PDH) activity.

Enhanced citrate synthase (CS) and COX activity for better mitochondrial efficiency.

Upregulated GLUT4, CD36, and PGC1a, contributing to improved energy metabolism.

Question 3

HITT Comparison to Endurance Training?

Answer 3

HIIT is more time-efficient but yields similar metabolic benefits (e.g., increased exercise capacity and muscle mitochondrial content).

Question 4

Effects of Detraining?

Answer 4

Reversal of adaptations:

Decreased mitochondrial content and VO2 max.

Reduced muscle glycogen and increased carbohydrate reliance.

Muscle fiber type reverts (IIA to IIX for resistance training).

Adipose tissue lipoprotein lipase activity increases

Question 5

Summary of adaptations to HIIT?

Answer 5

^ Endurance & sprint performance

^ VO2 max

^ Proportion of lipid to carbohydrates used during exercise, at a given absolute moderate intensity

^ Muscle mitochondrial content

^Muscle glycogen content

Decreased Muscle glycogen breakdown

Decreased Lactate production