I got a lot of great feedback from last weeks topic so thank you so much for all your comments and shares! I’m so glad that it helped you all out!
Special mention to Laura from Sprint To The Table (If you’re a foodie I know you know of her but here’s her site if you live under a rock :-P) said she felt like they were helping Vegas’s (her wife) stomach issues so I’m so happy that I could share that piece of info here.
Oh, and Laura, if you read this post, I challenge to to a Strange But Good twist on a gummy 😉
So hopefully this week’s topic also comes in handy and is informative. This is something that I think a lot of people wonder about when watching some individuals during their prep.
To ‘fasted cardio” or not to ‘fasted cardio’
That is the question.
There are no special benefits to it.
I think the interest and the trend of fasted cardio started to become “a thing” when people in prep started doing it more and more. Many people, when asked why they did it, would say that they are training their body to use fat because in the morning your glycogen (stored glucose) is lower and so when you exercise, you would be switching to using fat and therefore basically melting dat fat away..
Or something like that.
Well the research says otherwise. Well actually, it really says it doesn’t do anything at all.
Brad Schoenfeld (2011) –> He did a review (found here) on current literature and found a few things. First, individuals doing cardiovascular actives fasted vs. with a meal in them did not show significantly difference fat utilization. In other words, going in on an empty tank doesn’t mean you just start to burn all the fat. Second, and a major point, is that on top of the fact that it didn’t show a difference, those going in empty may not be able to train at an equal intensity due to fatigue. As a result they may actually have worse results due to not being able to work as effectively. Lastly, if you are trying to maximize muscle gains, be wary as protein losses during fasted cardio are quite large (according to his findings).
The bandwagon is lead by blind horses
Oh Alan Aragon….One of the kings in the Nutrition/Bodybuilding world. This guy should be taken note of as he actually reads le science.
He’s actually got a good sense of humour to him too.
Anyways, he wrote a post (found here and includes the earlier bandwagon heading) on fasted cardio and this is what he brought to the table:
~In the 68% group, no difference in fat oxidation was seen whether subjects were fasted or fed throughout the trial.
~Pre & during-training carbs increased performance – and there was no difference in total fat oxidation between the fasted and fed subjects. Despite the elevated insulin levels in the carb-fueled groups, there was no difference in fat availability or fat utilization.
~Carbohydrate during exercise spares liver glycogen, which is among the most critical factors for anticatabolism during hypocaloric & other conditions of metabolic stress. This protective hepatic effect is absent in fasted cardio
Interesting stuff eh?
One final article I will present (as there are so many saying how insignificant it is) to you also includes the aftermath of fed vs. fasted aerobic exercise on fat utilization.
Marlee Finkelstein (2015) did a summary of a few studies including one that found that the utilization of fat as a major fuel source 12 to 24 hours post-exercise is significantly higher in the FED states when compared to fasted ones. She also highlighted this fact:
In order to perform at an optimal level, it is recommended to eat before exercise. If you don’t, the fuel source comes from your precious muscles (protein), not fat. Rather than worrying whether to eat or not, focus on what you should be eating.
So yeah, like I said, I could give you humpteen journals, studies, etc that talk about how insignificant fasted cardio is in terms of fat loss. This is an old myth that needs to be shoved in the closet. Overall, the research tells us that:
1. You don’t see a significant differences in weight loss and/or fat utilization between fed and unfed states during aerobic training.
2. Fasted cardio is risky if muscle building is what you’re looking to achieve.
3. You’re deprived self may be hindering your progress as the lack of energy may mean you don’t train with the intensity that you need to stimulate the muscles enough for your goals.
I will close with yet another statement from Alan because I just love his stuff and he just makes actual sense.
Athletes are known for their gravitation towards self-sacrifice, but some rely on hearsay, while others rely on science. Did you know that way back in the 60’s, it wasn’t uncommon for coaches to tell athletes in various sports to avoid drinking water before and during training? No comment needed.
Basically, we often follow things that we don’t actually know the WHY behind them. Oh I see others do it and they get results. Or thats just what you do. OR Look at him, he’s in great shape so obviously he’s doing something right.
Stop following along and educate yourself or you are doing unnecessary work, or worse yet, harm to yourself.
As a final disclaimer (to cover all my bases), if you personally feel better training (I would say running is the major thing I’m getting at here) on empty then so be it. What I’m saying is there is no benefit of fasted cardio to body composition.
To each their own, but now you know.
What do you think?