The Benefits of Intermittent Fasting
What is Intermittent Fasting?
Intermittent fasting (IF) is basically a way of living where you deny yourself food for a given period of time (fasting phase) and then break the fast and eat the bulk of your calories during a certain window. For instance, if I was to follow a 19/5 IF, I would not eat or drink anything but water for 19 hours of the day and then eat all of my calories in the five hour window that follows.
It really is a lifestyle, because you quite frankly have to change the way you live in order to do this. You won't be eating breakfast or lunch like "normal" people do - and 19 hours is a long time. You only spend about 8 of that sleeping, so one of the biggest challenges is finding something to do the rest of that time when you'd normally be preparing food, eating food, or thinking about what to eat.
Will Intermittent Fasting Improve Your Boxing and Training?
The ultimate goal of the nutrition information on How to Box is to ensure that what you eat and how you eat it is going to either improve your ability to box or improve you level of conditioning by supplying more energy, decreasing your bodyfat, or increasing your muscle. So, can intermittent fasting deliver in any of those areas?
IF does go against some widely held beliefs such as the one that one should eat 5-6 smaller meals spaced throughout the day to ensure your body has a steady supply of nutrients. Protein in particular, that cannot be stored, would seem to be lacking by following such a regimen at certain times of the day which could potentially harm muscle growth. The real question is - does it?
Most of the information available regarding IF refers to human evolution and how for thousands of years humans were forced to go for large periods of time without eating. We'd have to go out, expend a lot of energy, and hunt for our food often resulting in one large feast rather than many small ones. Further, those meals would not contain high amounts of carbs, especially the processed carbs we eat today. There'd be some fruit, nuts and so on, but it would not have been the bulk of the diet, which is completely the opposite of what the typical diet looks like today.
I've experienced the benefit of eating 5-6 times a day in gaining about 12lbs of lean mass while decreasing bodyfat by approx 5%, so I naturally have some resistance to an intermittent fasting regime. That said, doing a bit of research has quelled my fears a bit which included question such as:
- Q: Will it slow down my metabolism?
A: No, no real difference in the thermogenic effect between people eating frequently vs people eating larger meals infrequently.
- Q: Does intermittent fasting invoke the starvation response?
A: I'm going to do a separate post on the "starvation response" because it is something that is largely misunderstood. Various diets have suggested that this response is invoked if someone denies themself food for extended periods of time which slows the metabolism to a halt and causes future weight loss issues.
That's only partially correct. It is more related to the amount of fat on your body. If you go below a certain level, the response is invoked to prevent you from starving to death. It doesn't happen for short term fasts unless the person doing them is already literally starving themseles to death. Regardless, I only found one study that reported a metabolic slowdown and it didn't occur until 60 hours into the fast. IF will not have this issue.
- Q: Am I going to be hungry all the time?
A: Possibly. I've found conflicting information saying yes, some saying no, some saying it will last until you're used to the fasting cycle, some saying it happens to some people and not others. I look at it this way. I currently get hungry around the times I regularly eat. If I create a new cycle, I suspect that my hunger is going to start peaking right around the time that I know I'm going to be able to eat again. Besides 19 hours isn't all that long especially when a good portion of it is sleeping anyways.
- Q: Will fasting attack my muscles and prevent muscle growth?
A: This is a big concern of mine. I like the muscle I have on my body and don't want to lose it and a lot of literature exists that suggests if you do not eat enough, then your body will start to use muscle as fuel.
Well, apparently during the fasting phase, your body is going to be eating your fat reserves - at least until you don't have any fat left. It does this, because it's first energy source, being the glucose stored in your muscles, liver, brain, etc... are depleted within a couple of hours (or less if exercising). That's one reason that some people suggest training in a fasted state - to target fat. From the reading I've done, as long as you consume some protein (most suggest BCAAs) prior to working out and then consume a post-workout protein source, there is no muscle loss and one can even add muscle.
Protein seems to be the key and ensuring you have enough of it when your body needs it. Fasting also makes your body more efficient at using the protein during and after the workouts.
- Q: Are my workouts going to suck if I have no energy to do them?
A: Apparently you get used to it and then intensity of your training will not suffer. All the boneheads saying that their blood sugar is too low and they need to power up before working out have mental problems. Even in some diabetic studies I foun, blood sugar is not an issue during fasting for intermittent periods.
Pros and Cons of Intermittent Fasting
Following is a list of other reported pros and cons I discovered regarding intermittent fasting. I can't tell you if they are all true or not, they require more research to quantify, but I figured I'd list them here anyways until I get around to checking them out. Eat Stop Eat is an awesome resource on intermittent fasting as well as a website called Leangains.com:
- insulin is kept low during fasting meaning fat is the primary fuel - excellent for those trying to lose some bodyfat
- Human growth hormone (GH) increases during the fast - excellent news for those trying to add muscle
- During fast sympathetic innervation gets more stimuli - as fat cells have that, they get additional stimulation
- Your digestive cycle is getting a big break. As it uses 10% of your energy or more everyday, that energy can be channeled elsewhere. As well, the blood usually used in the digestive cycle can be redirected to your other tissues - including fat cells which usually are the last cells to get blood to cleanse them.
- Live longer with better brain function. Things become a lot clearer apparently and calorie restriction has been shown in studies to increase life expectancy.
- You have more time to be productive. You don't have to worry about preparing a couple of extra meals a day.
It's really easy to create a caloric deficit everyday as you try and fit all your calories into a 5 hour window. While it's not recommended to binge on junk - you still want to eat healthy - you can eat a lot of things that keep you very satisfied during the upcoming fast.
- You'll probably get hungry. Face it, you miss breakfast and lunch and you've been trained to expect them daily for your entire life. You'll have to get used to this new cycle - but being hungry won't kill you.
- Your morning weight vs your evening weight is very different. When you eat a lot of calories, you're going to notice it until it gets digested.
- It doesn't fit into normal social norms. People are going to think you're crazy by not eating breakfast and lunch.
- Training in a fasted state takes some getting used to - it's mostly mental, but you'll need to overcome the thoughts that tell you you have no fuel to burn.
After spending a good portion of the last few days reading about the benefits and drawbacks of intermittent fasting, I've concluded that it is something that warrants a lot more research and specifically I'm interested in how it affects my body and training. So, I'm embarking on a bit of an experiment where I will be following a 19/5 IF regimen. At the same time, I'll be incorporating some fasted state training as well as some strategically timed meals after breaking my fast to get the most out of my workouts. With any luck, I'm going to see huge gains in strength and body composition in the shortest amount of time possible. I'll keep you all posted on the results.
I'd also encourage anyone interested to give it a go as well and report your results here.
My Intermittent Fasting Setup
I'm going to be fasting daily to start with from 2100hrs each evening until 1600hrs the following day for a total of 19 hours. Some people do a 24 hr cycle every couple of days as Eat Stop Eat is a proponent of. Others do a 16/8 cycle such as seen on Leangains.com. I'm going to be trying this one kind of inbetween.
Regardless of when my workouts are, I will be taking a 40g protein shake (minimum carbs) about 15-20 min before the workout and another 40g protein shake immediately after working out. While BCAAs are the recommendation for doing this, I've never used them and believe I can get similar benefits out of a good whey protein which I know my body likes.
The only thing I will consume during the fast phases are water and pure green tea. Apparently unsweetened coffee and other zero calorie drinks, chewing gum, etc... are ok. I think I can get along with water and green tea as those are the only things I drink anyways.
As usual, I'll continue to get at least 7-8 hrs of sleep a night in order for my body to rest and rejuvenate.
When I do break the fast, I'm going to be aiming to consume about 500 calories less than my maintenance level (so approx 2200 calories of good quality foods). I'm looking to get down to 6% bodyfat while not losing any lean muscle mass. Would even be better if I managed to put some on. Guess we'll see how it goes.
Update 22 May 11 - Three Days In
So far so good. I've had zero issues following my plan and have not experienced any debilitating hunger during the fast phases. My first workout session in a fasted state was not all that great. Did some dynamic training that nearly had me puking at the end of it. I've never been a puker, but it felt bad. I attribute that to the lack of food in my stomach. That said, the rest of my workouts have been EXCEPTIONAL. Today especially, I had one of the best strength training workouts I've had in recent memory.
I took my measurements on the first day of the fasting. I'm not checking them again until a week in, so I can't comment objectively on any body composition changes. Subjectively, I feel a lot more energetic, clear in the head, and have been able to get a hell of lot done during the day without having to take food breaks. Looking in the mirror, I'm 95% sure my body is reacting exactly the way I hoped it would - shedding some fat and possibly even adding some muscle. Have a feeling I'm going to be ripped for an upcoming vacation in about a month's time. Looking forward to it.
All in all, pleasantly happy and surprised with how it's going. I'll update again on Friday when I can put some objective results on the board. Take care and Boxon.