Two key questions covered in this article:
- Is there a right and a wrong time to do cardio for fat loss?
- If I need/want to do cardio anyway, is there a right and wrong time to do it?
Q. Is there a right and a wrong time to do cardio for fat loss?
A. Yes and no.
Cardio for fat loss is nearly always a bad idea, it is an exceptionally poor time investment and not necessary. Two exceptions:
- Exceptionally lean individuals trying to get the stubborn fat off themselves. (More on this below.)
- Small women that due to their size actually don’t qualify for much food each day to maintain a calorie deficit, and they’d literally prefer to move more to allow for bigger meals.
|A Recap on the Nutritional Hierarchy of Importance for Fat Loss
1. The most important factor in whether you gain or lose weight is the net calorie balance for the day. Fat, or more accurately free fatty acids, are constantly being shuttled in and out of the fat stores throughout the day. Whether you are left with more or less at the end of the day is down to your energy intake vs expenditure. You can eat less, or move more to achieve this but the net result between the two will be the same.
2. The second most important factor – the macronutrients that make up that calorie balance, as this affects the degree to which we gain/lose muscle relative to fat when bulking/dieting.
3. Nutrient timing comes in a distant third. – This is why I don’t tell clients to rush home and eat “within an hour” or something like that. (I’m purposefully ignoring micronutrition, as that’s not going to keep you from losing fat, but it is important for health.)
The thing I want you to take away from this is that cardio, regardless of time performed, is unlikely to have any affect on overall fat stores at the end of the day – the energy balance and the macros are way more important.
The exception to the above is in the case of the exceptionally lean individual.
On stubborn fat removal
Firstly, let’s define stubborn fat as being the fat that is physiologically different and thus difficult to burn off. Stubborn fat is the fat on your lower back, legs and butt, and unless you’re already looking like the guys above, you don’t have any stubborn fat concerns yet, it’s just fat.
Fasted cardio may increase the theoretical limit on the amount of fat burning that can take place in a day by providing greater access to the stubborn body fat. Cardio improves blood flow around the body, and doing it when fasted provides hormonally favourable conditions for shifting the stubborn body fat (insulin down, catecholamines up, etc.).
Does this mean we should all do fasted cardio to get shredded?
No, you should be able to get to a similar condition as the guys in the images above before needing it to get at the stubborn fat. Related article, ‘When is Cardio a Valid Tool for Fat Loss with Intermittent Fasting?‘ (Or geek out on this with Lyle McDonald’s book here.)
Q. If I need/want to do cardio anyway, is there a right and wrong time to do it?
It depends on how serious you are about this cardio work. If you’re doing cardio just for fun, the it doesn’t really matter what time you do it.
If you are fairly serious, you have a race for example, and are looking to increase cardiovascular and respiratory endurance further, you need to think of the impact that the strength workouts will have on that training.
If you’re doing marathon training for example, you will be running several times a week. From my limited understanding is that the once weekly longer run is key for driving endurance adaptations. So, although it’s impossible to position your strength workouts without compromising some running sessions, you will want to give yourself at least enough time for recovery so that the long run isn’t compromised. (Lyle McDonald has a good article on maintaining strength whole marathon training here.)
Important to note: Endurance work can compromise strength adaptations. Running is arguably the worst for it, so if you don’t have good reason then avoid it. More on this in my article, ‘On Cardio for the Physique-Focused Trainee‘.