Depending on what you are doing, there can be qualitative changes in effects with changes in intensity or duration.

High intensity interval training HIIT is said to be good for both fat loss and performance
improvements. That usually involves alternating periods of extreme activity and rest.
At one extreme you have Tabata protocols like 20 seconds work, 10 seconds rest,
repeated 8 times. That’s about 4 minutes!
Ideally, you work so hard you want to die but your wish remains unfulfilled. :^)
Of course you can adjust the time to be longer (e.g. sprint 200 meters as fast
as you can, walk or jog for the same amount of time, repeat several times).
But the emphasis is on intensity. Sprinting as fast as you can is potentially
dangerous. For HIIT the safest exercise is probably cycling on an exercise bike.
Supposedly HIIT results in (major) hormonal changes favorable to weight loss.

With resistance training you can of course do HIIT but the traditional protocols used to gain strength
are not HIIT and HIIT might be dangerous if you’re moving large weights around (slamming out 20 deadlifts as fast as I can is however fun. I look like a bobbing duck.). Slow is good and folks recommend going to “momentary muscle failure” with slow movements. This in theory strips as much glycogen from muscles as possible.
It’s probably not obvious why slow-exhausting resistance training helps weight loss, but one link
is that — if you are insulin resistant — resistance exercise triggers uptake of glucose by muscles
independent of the insulin signal. You turn your muscles into glucose sponges, reducing
blood glucose and hopefully insulin. I’m experimenting and it seems to work for me. And
fasting doesn’t interfere with exercise at all. I feel great.
Doug McGuff’s book Body by Science is a good reference.

And of course there is aerobic. I happen to like kayaking a lot and given my skill level it is a barely aerobic activity (like walking fast). From what I’ve read low-intensity aerobic activities
contribute little to weight loss and may in fact impede weight loss. So I don’t think of kayaking
as an aid to weight loss and maybe it serves as an impediment.

The fasting folks recommend doing exercise while fasting (e.g. in the morning before eating if you fast overnight). The notion is that you will burn fat for lack of glucose.
And fasting and exercise combined seem like a fast way to reach ketosis. I’m self-experimenting.
I’ve gone a couple of times from “happy carb-filled body” to ketone level of 1.6 or higher in just over 24 hours of fasting plus a crossfit session (which combines resistance training and HIIT).

Hope that helped,

L