For the average person, the answer is no. You're not going to burn more fat doing fasted cardio. They should focus on doing it when the time's right for their schedules.

Lean folks on the other hand... things can be a bit different. Let me first say that plenty of lean folks have gotten leaner implementing 'fed' cardio. It's not that it can't work. In some instances though, fasted cardio can be better. The reason being has to do with what's happening with fat cells and the process of getting the fat out of them. As people get leaner, the process tends to get a little wonky. It's almost as if your body wants to hold onto it... which makes some sense if you relate it back to caveman days.

Fasted cardio can offset these negative adaptations a bit, thus making it easier to get fatty acids to the oxidative (burning) stage.

In reality though, it's going to be a matter of experimentation. Lyle McDonald's book, the stubborn fat solution, goes into this topic in painstaking detail. Interesting read for sure.

...Lean folks on the other hand... things can be a bit different. Let me first say that plenty of lean folks have gotten leaner implementing 'fed' cardio. It's not that it can't work. In some instances though, fasted cardio can be better. The reason being has to do with what's happening with fat cells and the process of getting the fat out of them. As people get leaner, the process tends to get a little wonky. It's almost as if your body wants to hold onto it... which makes some sense if you relate it back to caveman days.

Fasted cardio can offset these negative adaptations a bit, thus making it easier to get fatty acids to the oxidative (burning) stage.

Steve, what's your opinion on the effect of fasted cardio on LBM? I've read conflicting viewpoints. I'm not particularly lean yet (still around 19-20%), but trying to hold on to as much muscle as possible while leaning out. I realize that some LBM loss is inevitable in the process, but just wondering if fasted cardio is more deleterious than 'fed' cardio in that regard.

You know, if you searched hard enough, you'd find posts made by me on other forums a mere 3-4 years ago warning against fasted cardio. Looking back though, it's not something I ever experimented with and was basing my assumption on my own conceptions and dogma. After some experimentation though, my thoughts have changed a bit.

I'll say this. If you're realizing decent rates of progress with fed cardio and that's what you enjoy... you shouldn't change simply for the sake of changing. But if you're struggling a bit to tap into some of the last bits of fat, and you're confident that your nutrition is dialed in, you might find some success with fasted cardio.

The risk? As you noted... muscle loss. But in reality, I don't think it's something to concern yourself with. Especially if you're eating a higher protein diet... something in the tune of 1 gram per pound (per pound of lbm if you're carrying a lot of fat). The only time I'd be concerned about losing muscle would be if you were doing prolonged fasting.

I'd say that's a good idea. I'm a subscriber to the KISS. At least until simple stops working.

I've read the book and you can't argue with the fact that some people respond extremely well to an intermittent fasting approach. That said, I've seen where some people are the exact opposite. Their mindset actually is contraindicated for IF. In these cases, IF seems to lead to eating-disorder like tendencies.

Like most things here, I think it's a matter of being honest with yourself and experimenting on those things that seem reasonable relative to you and your circumstances.

In particular with IF, I'm not on board to the point where I think there's super powerful physiological responses to the diet. There *might* be some improvements in partitioning (where calories are going and coming from), but if so, we're probably splitting hairs. I think for those folks who do the best with it, it simply proves to be a very effective diet structure for controlling calories and nutrients... and as we know, that's the overwhelming factor when it comes to improving physique.