Fueling Workouts Part 1
What to eat before and after your workouts
In a previous article, I dispelled the myth that it’s bad to workout on an empty stomach, but I never got into the details of what you could (and should) eat afterwards. That article also was solely talking about weight loss, but different fitness goals have different pre and post workout meal requirements to get the most out of all that effort. Proper nutrition can be as important or an even more important component of your fitness plan than the workout itself, which is why I’m starting this four part series to go over what you should eat and when depending on your goals. In the coming weeks, I’ll cover the different pre and post workout eating strategies you should use for:
- Muscle Building
- Race Training
- Weight Loss
This article will be more of an overview concerning how nutrition and exercise effect your body and the general role that each plays. I may give some specific portion sizes here and there, but I plan to be intentionally vague for two reasons:
1. Everyone is different: There are all kinds of factors that effect how each of us responds to different foods such as height, weight, age, gender, and a host of genetic sensitivities. No one piece of advice applies perfectly to everyone, but there are some general guidelines that will help you shape your own diet plan. The point of this series is to give you an understanding of how our bodies typically respond to certain foods, but it’s up to you to determine how your body responds. Your body constantly sends you a host of signals, and part of getting fit is learning how to properly interpret what your body really needs. Are you hungry or are you just thirsty? Are your legs feeling like lead because you’re overtraining or because you didn’t refuel enough the day before? Don’t take any numbers given as gospel. It is your job to pay attention to how you feel and monitor if you’re moving properly towards your goal so you can adjust the numbers as needed.
2. Most recommended portions come from athlete studies: The majority of the pre and post workout dietary recommendations you’ll find are based upon studies performed on athletes. These extreme examples provide excellent incites into what happens to our bodies, but the conclusions cannot always be applied to the average exerciser. If you’re not exhausting your body to the level these test participants did, then you may not need the same level of nutrition to replenish yourself. Our bodies are designed to endure and thrive in much harsher conditions than we put them through today. I usually recommend erring on the low side for dietary requirements as you feel out what your body needs. No matter your goal, you don’t want to pack on excess body fat as you fuel your workouts, so start conservative and add fuel as needed.
We’re not so delicate
One of the big things I like to communicate to people when it comes to exercise nutrition is that you should try to be aware of the signals your body is sending you. We are not as fragile as I’ve seen communicated by companies trying to sell you sports drinks and nutrition bars. You can trust your body to tell you when it needs water and fuel. Forced hydration and forced nutrition are generally pretty unnecessary. Serious body builders will need to stuff themselves to stimulate growth, but the average person can just eat reasonably and expect to get results. No matter your goal, nutrition will play an important roll, and with anything, the more extreme your nutrition plans, the less likely it is to work. All you need are some reasonable adjustments to your current diet plans, and you’ll hit your goals with ease.
Fitness breaks you down
Before we dive into specific recommendations, I want to give a little background on the roles that both exercise and nutrition plays in creating a catabolic environment (where your body breaks down tissue for fuel) and an anabolic environment (where your body uses fuel to create tissue).
Exercise of any form triggers your body to break down tissue (including both fat and muscle tissue), but depleting your energy stores of blood sugar and glycogen (sugar stored in your muscle cells) causes a much greater catabolic response. So the most basic idea is that if you want to burn off tissue (like stored body fat), you don’t want to introduce that much fuel before a workout. If you want to preserve or actually increase tissue (build muscle), then you want to introduce an adequate supply of fuel to the system before you workout.
In response to the stressor of exercise, your body releases cortisol, adrenalin, and noradrenalin to break down tissue and provide your body with the fuel it needs. Everyone likes the idea of fat cells being broken down to fuel your workouts, but they don’t like the idea that muscle is broken down into amino acids and then converted into glucose in the liver. Not all muscle broken down into amino acids is used as a quick fuel source. Cortisol also serves to create a reserve of free floating amino acids to help repair and build muscle in the absence of dietary proteins. In other words, if you’re not providing your body with protein building blocks, it will do its best to repair what it can by moving existing blocks around. Obviously, this won’t work forever, and without proper dietary protein, you will steadily lose muscle tissue. Even if your goal is weight loss, no one wants to lose muscle tissue, so proper nutrition surrounding your workouts is a key to meeting your goals.
On the nutrition side, if your body has plenty of available fuel or the exercise is not intense enough to deplete your reserves, then your body has no need to tap into fat stores and muscle tissue for fuel. This is why the recommendations for muscle building, event training, and weight loss are so different. If you’re trying to lose fat, you’re going to sacrifice a little muscle tissue (but there are ways to limit the loss). If you want to build muscle, you will need to feed that growth, and if you’re training for a race, you need to figure out an eating strategy that will fuel your muscles all the way through your event.
I heard cortisol is bad, so is exercise bad?
I’ve found that a surprising number of people have heard of the hormone cortisol, and they have all heard that it’s this horrible thing that should be avoided. The original purpose of cortisol was to quickly mobilize energy so we could run away from saber tooth tigers. It was meant to help us survive by mobilizing fat and protein for fuel to feed our fight or flight response.
In our modern world, this stress response can cause problems. The stress from exercise is actually quite short, and while it does create a catabolic environment in the short term, it helps create an anabolic environment quickly after the end of your workout. The real problems with cortisol comes from prolonged stress (like from a stressful job, constant lack of sleep, or frequent fights with a spouse). Continuously elevated cortisol levels can cause muscle breakdown, bone loss, insulin resistance, and fat gain, plus cortisol has been shown to suppress your immune response and lengthen the time it takes to heal wounds. Cortisol is meant to prioritize fuel creation in the short term at the expense of some other important functions. Prolonged release of cortisol messes up your body’s priorities and can lead to dysfunction. This is why too much stress and too little sleep is so bad for your weight, health, and immunity.
While exercise can raise cortisol levels, it only does so for a short period of time. In addition, your body adapts to the stress of exercise and releases less and less cortisol during each workout as your fitness improves. This is actually one of the reasons why exercise is good for stress and for your immune system. As you become more fit, your body uses less cortisol in response to other stressors, so life’s little stresses are less impactful to your body and health.
Break down your old body to build up the new one
While exercise creates a catabolic environment to break down fat cells and (to a lesser extant) muscle cells, you can quickly switch your body back to an anabolic environment where it’s rebuilding damaged muscle fibers and creating new ones IF you provide food to work with. It’s what makes us so adaptable to our environment. Our body constantly reshapes itself to deal with the world around it, but to properly adapt, your body needs fuel (carbohydrates and fat) and abundant building blocks (protein). While there are different nutrition plans for different goals, I want to quickly go over an important post-workout concept that will apply to pretty much any goal.
Exercised muscles are starving for nutrition
If you workout hard enough to deplete your muscles’ stored glycogen, then your muscle cells will be hungry to replace it afterwards. Normally when you eat carbohydrates, your body releases insulin to deliver blood sugar to working muscles or to the liver where it converts the sugar to glycogen (if the muscles aren’t already full of stored glycogen) or as fat (if your glycogen reserves are full). Insulin also tells your body to store any fatty acids in the blood stream in fat cells and to NOT RELEASE any stored body fat. This is why sugar is so fattening. Few people actually ever deplete their glycogen, so nearly all the sugar is stored as fat and all the fat they eat for hours afterwards is also stored as fat.
However, after a strenuous workout, your muscles are able to grab sugar out of your blood stream without insulin for a few hours. Even for those trying to lose body fat, a post-workout meal is a great time to replenish depleted glycogen without putting your body into fat storage mode. Working out with depleted glycogen levels can help burn more body fat, but it can also be more challenging for the average person. I think it’s a good strategy for weight loss and I’ll get into that later, but if you find your workouts getting increasingly difficult, a post-workout refueling will do wonders.
Next time, I’ll go over the specific strategies related to muscle building. To grow tissue you need to eat, but choosing the wrong foods will lead to body fat gains. I’ll go over the eating strategies you should employ around your workouts, and some general guidelines of what to eat throughout the rest of your day.