What kind of exercise is best for losing fat?

This question is usually asked in search of whichever exercise burns the most fat per hour, which is a way of measuring that produces the wrong answer — because what decides the long-run result is not the number in that hour.

Why does the scale move less than the calculation says?

Because the body compensates. Partly through increased hunger, partly through moving less for the rest of the day without noticing — the research calls the second one a fall in NEAT.

Pontzer and colleagues, studying energy expenditure across several populations, argued that total daily expenditure is more constrained than a simple additive model suggests. Running off 300 calories does not always add 300 to the day's total.

The usable conclusion is: do not make exercise your only tool for losing weight, but do not conclude it is useless either — what it gives you is in a different category.

Cardio or HIIT?

For the same energy expended, the effect on fat is similar. HIIT's real advantage is time: comparable results in less of it, which matters a great deal if time is the constraint.

Its downside is that it is hard, recovery is slower, and it cannot be done daily. Someone doing HIIT three times a week and then being too wrecked to move on the other days may spend less energy across the week than someone walking briskly for forty minutes a day.

Is there a fat-burning zone?

There is, in a narrow sense, and it is misunderstood almost every time. At low intensity the body does use a higher proportion of fat for fuel — while using far less fuel in total.

An easy hour of walking might use 250 calories, 60% of it fat, which is 150. An hour of running might use 600, 35% of it fat, which is 210. The second burns more fat despite the lower percentage — and that is before noting that what really decides the outcome is the whole day's energy balance, not the fuel mix during that hour.

Where does resistance training matter?

It is the only thing that tells the body muscle is still needed while energy is short. Cardio does not send that signal at anything like the same strength.

In numbers: the same weight lost with muscle preserved, versus with muscle lost, produces a very different shape and a different daily energy expenditure — which then affects every round after this one.

How many steps a day is enough?

Paluch and colleagues (2022), pooling data across several cohorts, found a dose-response relationship where more is better, with benefits levelling off around 6,000 to 9,000 steps a day in middle-aged and older adults, and somewhat higher in younger ones.

The familiar 10,000 comes from the name of a pedometer sold in Japan in the 1960s, not from research. That does not make it wrong — it means you need not feel you failed at 7,500.

So how should a week look?

• Resistance training two or three times — the part that protects muscle. Never the first thing cut when time is short.
• 150 minutes of moderate cardio a week — the general health guideline, which has reasons of its own quite apart from weight.
• More walking in ordinary life — this adds more to daily expenditure than people expect, and it is the part that quietly falls away during a long stretch of dieting.