I'm not an exercise physiologist but I have an interest in it. The article states that more energy is used when the body is gearing up for an activity and I'm guessing this is because if you exercise for only up to a few minutes at a time with sufficient rest in between intervals then you'll end up mostly using the phosphocreatine and anaerobic glycolosis systems which are less efficient than aerobic glycolosis or aerobic lipoylsis. It's why when you start running without a sufficient warm up, you're always a bit out of breath even when running at sub maximal efforts and later on in the same run, even when running faster, your breathing can be super relaxed. The aerobic system takes a while to "spin up". In other words, you start with poor running economy... using more calories to run the same speed but as your aerobic system spins up, your running economy increases and you use less calories to run the same speed.

It's my understanding that by doing the type of exercise mentioned in the article - short bursts - you'll get positive physiological adaptations to your anearobic capacity but it won't have much impact on your aerobic capcity, which I would argue is the more important system to train for everyday operations of the human body!

I hate shopping, because it’s start and stop all the time. I get tired after only 30m.

Then, I’ll walk home from the office (1h) and will have lots of energy to actually DO something.

The title resonated with me very strongly.

This is because maintaining inertia is efficient, despite the stress on the system. This is the reason High Intensity Interval Training and High Intensity Resistance Training work at all, because you're making a conscious effort in your exercise methodology to eliminate momentum and acceleration from the movements, which increases the work done within the context of your body, reducing the exerted energy lost to mechanical inefficiency of repeated movements.

You don't even need to stop moving while walking to see this effect in action. Just try walking so slow that you've eliminated almost all the momentum from the motion of walking. Just try it for a minute straight and see how it feels. (Forewarning: It's going to look ridiculous, like you're walking in slow motion.)

The article doesn't say what is the best burst duration. From paper:

> Our findings show that the time-averaged oxygen uptake and metabolic cost are greater for shorter than longer bouts: 30-s bouts consume 20–60% more oxygen than steady-state extrapolations.

> After each bout, V̇O2 was measured during the recovery for 7 min while participants were sitting on the same chair

So, each participant (there was 10 participants) done a trial of bouts, each bout randomly 10-240s plus 7min rest.