Interval training versus linear training

Question

What are the pros of interval training over same intensity training over the same period?

For example, I walk for 1 min @6kmph and then run for 2 mins @9km/hr, repeat for 10 minutes.

Contrast this with walk @6kmph for 2 mins + run @9kmph for 8 mins.

Which style should I prefer for better workout?

Answer 1

According to Jack Daniels, the difference is the following:

• interval training aims to increase your VO2MAX by targeting high intensities, which can't be maintained for a longer period. By design it achieves to maximize the overall volume for those very high intensities because you have breaks between each interval.
• longer (several kilometres) tempo runs aims to increase your lactate threshold by targeting a little bit lower intensities.

Also see training intensities.

Answer 2

There is no general answer. Your individual response to high intensity training (HIT) might be in parts genetically determined. You might be anything from a non-responder or a good responder. Watch last half a BBC documentary, "The Truth About Exercise" with Michael Mosley, for more details as I just did (and stumbled upon your question) If you are a "good responder", HIT will probably work very efficiently on you, and doing little HIT/week will suffice to get good results.

Using molecular classification to predict gains in maximal aerobic capacity following endurance exercise training in humans

It's a field of active research. There is only (?) one study with few participants.

These genetic tests mentioned in the documentary are not available to the general public, AFAIK.