Fasting is an area of health and fitness that has grown massively in popularity over the past decade and is beginning to enter the hockey world.
I get asked every single week if hockey players should do intermittent fasting, so I thought it would be highly beneficial to do a comprehensive article on the topic and its relevance toward the hockey strength and conditioning industry.
In this article, I will focus on resistance training while fasting. Resistance training represents training with any form of resistance: bodyweight, weights, cables, and bands.
I want to start by honing in on resistance training because it plays such a dominant role in a hockey athlete’s yearly periodization, and I don’t want you to be getting less of a return on investment than you otherwise could be getting from your hard-earned efforts in the gym.
The Different Types of Intermittent Fasting
It was once believed you had to eat every two hours in order to “keep the metabolic furnace burning,” but once science destroyed that myth (sorry for the spoiler alert if you’re still in that camp), the idea of fasting became much more appealing to a large percentage of people.
Most hockey players don’t leave enough time for themselves to eat breakfast before work or school anyway; many other hockey players don’t even have an appetite in the morning, so the strategy of intermittent fasting matches their lifestyle pretty easily.
These are the most popular strategies (in no specific order):
- 16/8 = 16hrs of fasting everyday, with an 8-hour “feeding” window
- 20/4 = 20hrs of fasting everyday, with a 4-hour “feeding” window
- 24hr fast = Picking one day per week to not eat anything for 24hrs, normally a Sunday
(Each of these has its own positives and negatives, but this article isn’t about providing a comprehensive review of each intermittent fasting method individually.)
Intermittent fasting does have unique benefits, but like everything in health and strength training, they are very context-specific.
I am not for or against intermittent fasting; I am simply an observer of the scientific literature and choose to make decisions for the context of hockey players based on the specific physiological demands of the sport and their schedule.
Put another way, the only thing I’m invested in is your performance. This is important to care about because most who try to sell you on a new type of diet are doing just that, selling.
When you don’t have a dog in the fight it’s easier to make an unbiased and informed opinion, and that’s exactly what you’re going to get out of me.
A Quick Rant
I do have one rant I want to get out of the way first though before we review some important literature on the topic of training while fasted.
Currently, there is plenty discussed in the hockey training industry that isn’t based on much science. It’s unfortunate, but it’s true.
Normally I just let this stuff go, however, one of the things I get the most confused with is how some coaches encourage their athletes to perform fasted cardio in the morning while consuming Branched Chain Amino Acids (BCAAs).
Here’s a typical explanation you might overhear at a gym or rink somewhere in your city:
“In the morning you are in a fasted state since you haven’t eaten in over eight hours, so you will be primarily using body fat for energy use. This way, we can burn pure body fat. But, since we don’t want to lose any muscle mass while you do this, you should also have some BCAAs during your morning fasted cardio session.”
This theory can be picked on in a whole lot of different ways regarding big picture calorie balance, energy substrate use, rate of muscle degradation, and intracellular signaling. But to make this a more digestible rant and not get too far off-track here, let’s just pick on BCAA use during your fasted morning cardio.
First of all, fasted means fasted.
If you’re drinking BCAAs you’re not fasted anymore. This should be commonsense.
BCAAs contain 4kcal per gram, just like protein does—whether they admit that on the label or not. BCAAs are also readily available forms of energy substrate that can be used to fuel physical activity, especially in a fasted state. Thus, taking you out of your fasted state and into a fueled state.
For the required and potentially beneficial effect of fasted cardio (more on this in a future article when I tackle the effects of training cardio while fasted) you actually have to be fasted: no BCAA’s, no cream and sugar in your coffee. Nothing.
Providing direct fuel for your body during something that you’re calling “fasted cardio” is the epitome of a contradiction.
But there’s more here that really makes me scratch my head in confusion.
The whole idea of fasted cardio is to maximize the amount of mobilized fatty acids floating around your bloodstream (since you have been fasting for an extended period of time, glucose is not as readily available as it would be if you had a pre-workout meal), so that you can burn more of your own body fat during this session, and not glucose.
But, BCAAs directly elevate insulin levels in the body.
The research is very clear (for decades at this point in time) that even extremely low levels of insulin completely blunts acute fat mobilization/oxidation. Therefore, any amount of BCAAs that you take in before or during your fasted cardio is going to far exceed the amount of insulin required to block fatty acid mobilization.
Their idea was honest, they wanted to do fasted cardio to burn more fat but protect their muscle tissue with BCAA supplementation.
Expcept, what they ended up with was a physiological cocktail that took them out of a fasted state while simultaneously blocking fatty acid mobilization.
Ain’t that a kick in the pants, and this is why we do research folks!
Hockey Training for Muscle Growth While Fasting
When you are training for the purposes of muscle growth, you are going to activate a muscle-building signaling cascade known as mTOR.
Essentially, mTOR is impacted by both physical activity and the nutrient availability within your body—and by gauging these two contributing factors, it determines how much muscle is going to be built from this particular workout.
Without getting into too much detail (because this mTOR rabbit hole goes on forever), mTOR acts as a central point for many signaling pathways to take place, impacting important pathways such as:
- Genetic translations for muscle growth in skeletal muscle
- Amino acid accumulation
- Structural stress responses
- Glucocorticoid (stress/catabolic hormone) signaling
Simply put, if you do the following three things, you will be maximizing mTOR pathways:
1) Eat enough calories
2) Eat enough protein
3) Train within the correct intensity measures for strength and muscular development
This is an important distinction to make because mTOR activity naturally reduces its signaling when energy/calorie availability is low.
This makes perfect sense, evolutionarily speaking: it would not be very advantageous for our bodies to maximize muscle growth during periods of low food availability (particularly protein).
This is why we have seen in studies that consuming amino acids (1) before fasted training, or consuming whey protein (2) prior to fasted training, results in much higher rates of protein synthesis (anytime you see the word synthesis, just think “growth”).
Hormone synthesis is creating hormones, glycogen synthesis is making glycogen out of glucose, and protein synthesis is stimulating muscle tissue to be built, contrary to if you wait until after your training is complete to have your amino acids and/or whey protein.
So, strike #1 against fasted training for muscle growth is that it just doesn’t seem to optimize well-established cellular pathways for muscle growth compared to being in a fed state.
Moving forward, it’s important to point out that although weight training is eventually anabolic to our body, the actual process of weight training itself is highly catabolic.
Meaning, when we train hard, we are actually breaking down our own muscle tissue (3).
Beyond breaking our own muscle tissue down, we have already seen in the scientific literature that fasted training decreases anabolic signaling inside our body.
This is important to care about because not only are we breaking our own muscle tissue down during hockey training with no pre-workout meal to help protect us from that, but we are also training in a way that reduces the very signals we are working so hard to create while we are in the gym.
This means more muscle protein breakdown, and less signalling to build it back up—strike #2.
Since we know that consuming protein will decrease the breakdown of our muscle tissue during exercise (4), does doing this result in a better recovery?
The answer is yes.
We saw in this study that strength-training athletes (perfect demographic for this type of research in terms of relevance for hockey players) who consumed protein before and after training had better recovery and lower levels of muscle damage than the placebo group.
To me, this makes perfect sense: in order to create the greatest muscle growth response within our physiology, it would be wise to create the most suitable internal environment for that to take place in.
Will the body grow in a hungry and catabolic state? Instinct tells me, probably not. Will the body grow in a well-fed and protein-rich state? Instinct tells me, that makes a lot more sense.
But, instinct isn’t enough, and the very well-put-together argument you will see from the intermittent fasting community is the idea that your body is an incredible adaptation machine (which it totally is, there’s no denying that). And, they’ll say, because it is an amazing adaptation machine, that your body gets a lot better at regulating muscle loss/total body protein balance over time.
From here, they will present excellent data (5) that suggests the body “ramps up” anabolic signaling after fasted training, essentially making up for the loss that occurred from training fasted and super compensating to put you back into a positive protein balance (AKA: An anabolic state).
But this is to be expected based on basic biology.
This super compensation isn’t very “super”—it’s simply a compensatory mechanism for the body trying to make up for lost time.
It’s not “extra anabolic” compared to fed subjects; it just needs to operate at a faster rate to make up for muscle loss that occurred during the fasted training.
For example, think about your muscles like a ditch. If you are well fed, training hard might only dig your ditch one foot deep (muscle breakdown), so, post-training, you need to regain protein balance (back on to level ground), and then consume nutrients to start building on top of level ground (building new muscle tissue).
When you have fasted, your ditch becomes six feet deep, so the body has to upregulate compensatory mechanisms much more to just get you back into a state of protein balance, let alone add more muscle tissue.
The problem here is that pre-workout protein still seems to be superior for 24-hour protein balance despite the fasted compensation mechanism (6), and the available long term data on training while fasted still seems to be a bad idea for muscle growth (7).
And that, my hockey player friends all around the world, is strike #3.
You’re outta here!
With the current data available, I strongly believe that fasted training is a sub-optimal approach for hockey players who prefer to do their resistance training upon waking.
Hockey players who are training with resistance (especially if they are training intensely) should be consuming a protein source before, during, and immediately after training to create the best possible environment within your physiology to create maximal muscle growth.
If you liked this article and would like to maximize your approach to nutrition and hockey performance, you have to check out the Hockey Skills Accelerator program because it contains the Hockey Nutrition Masterclass I designed to help skyrocket your results and provide you “done for you” scientifically-based meal plans to improve your all-around hockey performance.