Written by: Kevin Cann
This is a question that I have received quite recently. There is quite a lot of contradictory information out there on the World Wide Web regarding this topic making it pretty confusing to those trying to take charge of their health and performance.
The first step to figuring out if Intermittent Fasting (IF) or Time Restricted Feeding (TRF) is for you is figuring out what your goals are.
Most of the time when I ask this question to clients I get a response that goes something like this “I want to get stronger and lose some weight.” There is nothing wrong with these goals. Being lean and strong I think is a great goal for everyone. The problem arises with our nutrition in this scenario.
Eating to get strong and eating to get lean are very different. A beginner in the gym may be able to do both as the strength gains are more due to neuromuscular changes than building more tissue. However, after a period of time training we need to eat in a surplus to pack on the muscle size and get stronger.
Many people understand this and think that fasting may be a way to help them achieve both goals simultaneously.
IF and TRF have a few different protocols out there. Some people recommend a 16 hour fast. This basically means that you consume all of your calories within an 8 hour period. Other protocols call for fasting for a full 24 hours.
Partaking in a fasting protocol has many pluses and minuses. Research has shown that IF can help increase insulin sensitivity, help decrease body fat, and may even be able to protect us from diseases such as Parkinson’s and Alzheimers. If maximizing your strength is your goal, I would not encourage you to utilize an IF protocol. Recovery is more than just your post workout shake, eating veggies, and sleeping well.
After strenuous exercise our body is recovering for 48-72 hours. This includes replenishing the glycogen stores that we lost during our training session. It is during this time period that we are building more muscle mass so we need to make sure that we are giving the body everything it needs to heal the damaged tissue from training and also enough to build new tissue.
Another critical piece to success fasting is getting enough electrolytes. Click here for more information on electrolytes and fasting…
The problem with IF for strength gains is most people tend to undereat. If we undereat here we will not have enough nutrients to build new tissue allowing our strength gains to climb. If we continue to fast while increasing volume and intensity of workouts, at some point we will not be able to recover well enough and training will suffer and begin to slide in the opposite direction.
There are many articles on the internet that will disagree with what I said above. I have read articles that claim that IF does not affect muscle growth if you supplement with BCAAs. I do not believe that BCAAs are enough in this situation. Muscle tissue requires much more than a few amino acids to grow. In conjunction with nutrients our hormonal levels are important and in order to optimize our hormones for muscle growth our glycogen stores need to be full.
When our glycogen stores decline our body begins a process called gluconeogenesis. Basically, we need glucose to function and in the absence of readily available glucose a hormone called glucagon begins to release it from the liver and muscle tissue as well as converting our stored fat for energy.
This does sound pretty great, and for fat loss it is, but not for getting strong. Most in favor of IF for everyone will cite studies that show that muscle is spared during a ketogenic diet due to our body’s production of ketone bodies. This research is pretty good and I am not going to argue that muscle mass can be spared.
I am not just trying to spare muscle mass, I am trying to put more on to hit my strength goals. Unless you are a beginner in the gym, fasting will not allow you to do this. Powerlifting coach Boris Sheiko writes my programs and he is famously, or infamously depending on your view, known for high volume training. If I do not get enough food in me I can notice right away as I feel more stiff and sore and my sleep is not as good. When I am eating enough I feel great. This is just me and an n=1 scenario nothing more.
Back to glucagon. When glucagon is present insulin is low. This is the natural checks and balances of the human body. The problem here is if we are attempting to get stronger and build more muscle mass we want more insulin. Insulin directly affects testosterone by increasing it. Testosterone is one of our most powerful muscle building hormones.
Chances are you will put on some fat during a time period where increasing strength is your goal. This is due to the very difficult nature of eating exactly what you need to build more muscle without eating any excess to store as fat.
Keeping a journal of everything you eat as well as how well training is going and measuring body fat can help to minimize the fat gain during this time period. If you are gaining fat quicker than you would like you can tweak carb intake as well as overall calories consumed. This is not a perfect science and will take some figuring out over time.
IF has some great benefits for fat loss and the prevention of neurological decline. If these are your goals skipping breakfast a couple days of week is more than ok.
However, if strength is your goal I do not believe that IF is for you. We need to make sure we give our body all the nutrients it needs to recover from training and build more muscle. We also want our hormones to set the stage for the correct muscle building environment.
As with most things in the fitness and nutrition world it all depends on what your goals are.
Hi Kevin,
“This includes replenishing the glycogen stores that we lost during our training session.”
If there are disadvantages to low-carbohydrate sports performance, it does not seem to be mediated as a function of carb refeeds/glycogen replenishment ==> see @themuscleprof Jacob Wilson’s post https://www.facebook.com/themuscleprof/photos/a.730681440388599.1073741828.730640917059318/824901587633250/?type=3&theater
Kevin,
Do you have any idea how the recovery window varies with age? Does 48-72 hours cover all ages of healthy people. Can you comment on how the definition of “strenuous” and the recovery time might change for people in their 50’s, 60’s, 70’s?
Thanks,
It is so individualized it is hard to say. I work with a 62 year old woman who squats 370lbs and pulls 415lbs. Her needs are much different than someone just trying to be healthy.
Tinker with stuff and see what feels best for you
That’s badass 🙂
Great post Kevin.
From my experience it’s very tough to continue building muscle whilst intermittent fasting. You still need to hit your daily macros and calories which rules out the 5:2 approach whilst it can be tough to consume everything in an 8 hour window.
It is however a great tool to utilise when it’s time to start reducing your calorie intake after bulking.
Thanks man
Is it possible that “pumping” yourself to bigger and leaner gains is possible. Meaning, two weeks of consistent meals and lifting, followed by one to two days of lean eating and no exercise. And then cycle that through again? (just an example – time periods could be modified)
There are some strategies like this, eating bigger on workout days and eating less on rest days.
Great information!
I am insulin resistant. So my doctor has put me on a ketogenic diet. I need to loose fat as fast as possible as I am now also suffering from low testosterone. I was curious, what are your thoughts on intermittent fast while on a Ketogenic diet? Also, I exersize 4 to 5 times a week, and my goal is to get lean and healthy and then bulk.
I use intermittent fasting from last year, and results are amazing, so much grateful for finding that 🙂
http://fastingandtraining.com/fasting-made-easy
i have to say this mirrors my experience. i have been remaining ketoic for over a year now, whilst keeping a weekly schedule of ca 30km of running, 2 HIIT sessions, and daily morning mobility excercise, with a very short sprinting session thrown in every now and then. combining this with IF has proven unsustainable; i would have to eat to the point of bursting in the evening to feel nutritionally satiated. it hasn’t been until i introduced BCAA (partial improvement) that started shifting things for the better. i’ve seen much better results once i switched to a complete essential acids complex. but ultimately upping the calories showed the greatest shift in energy and muscle hypertrofy. i had put on a couple of perc of BF, but this is rebounding from a 5-percent-BF low that i’d almost inadverently reached via ketosis & excercise. it is sometimes only in retrospect that we realize the deleterious effects of this protocol– lowering thyroid hormone production, elevating stress hormones, and lowering testosterone. upping calories in general, and cycling in an out of ketoic states, IF-ing on non-workout days and having breakfasts on workout days, has proven the best protocol in my n=1 experiments.
I love the post and the reminder that diet/lifestyle isn’t one size fits all. Sometimes we get so caught up in the latest approach that we forget it won’t be perfectly suited to every situation.
Crystal clear… thank you for this useful article that explain in a short but effective way the main points of this over-discussed but not yet simplyfied (in the positive sense of the word) for everyone.