How to use food to support your training.
by Victoria Lim
Exercising is an excellent way to stay in shape, but diet has a significant role in health and fitness as well. Help your body recuperate quickly by consuming the right blend of nutrients for the right reasons.
Glycogen is basically a large molecule which serves to store glucose. It’s produced by the liver. Once your blood sugar level drops, this molecule is broken down and released into the bloodstream.
Also, you know how you are told you lose excess water every time you start a weight-loss diet? Every gram of glycogen binds to 3-4 grams of water, so what you’re actually burning through are your glycogen stores.
Most people can only store around 100 grams of glycogen in their liver and up to 400 grams of glycogen in their muscles. In total, this accounts for 1200-2000 calories – which is enough for 90 minutes of endurance training.
An alternative source of fuel, ketones (pronounced ‘key-tones’) are also created in the liver, but from fat stores instead of sugar. Most people enter ketosis after fasting (such as overnight) and it’s a normal adaptation, designed to give hunter-gatherers an edge during colder months when they did less gathering and more hunting.
Ketogenic diets aim to use ketones instead of glycogen for energy. This may give some people more consistent energy levels and avoid blood sugar spikes, and there’s some evidence the diet is neuroprotective (it was developed for treatment-resistant epilepsy in the 1920s, for which it works very well).
The ketogenic diet avoids large quantities of carbohydrates (the limit can be anywhere from 20-150g net carbs), although high-fibre foods are allowed (deduct fibre from total carb content for ‘net carbs’). Protein is also limited, because that can be converted to glycogen in the liver if you eat too much.
Given that pure fat has more energy than sugar, your body can store 90,000 calories or more in fat (but you need a minimal amount of fat for the proper functioning of your body).
However, there is a period of up to four weeks where the body switches to fat-burning, called keto-adaptation. During this period, the body struggles to access energy from either sugars or fats, so you may get a flu-like feeling until it passes. A fast helps enter ketosis quicker (sometimes taking only a few days).
What happens to glycogen during a workout is that its glucose is used to fuel the activity. If your training is particularly exhausting, you will use a greater share of the glucose stored.
There are about 2000 calories worth of glycogen stored in your body. Once that is used up, the body enters a state known as “hitting the wall”. You literally have no energy left.
While you exercise, your muscles reach out to the energy supplies in the body. Apart from glycogen and ketones, there is another energy molecule.
Adenosine triphosphate (ATP) is produced in your mitochondria, feeding your muscles and organs with energy from carbohydrates, fat and protein. When your body starts running low on supplies, it will start craving additional oxygen.
With the lack of oxygen, your body switches from aerobic to anaerobic energy production. What actually happens is that lactic acid is formed as a by-product, and with its build-up, you can get feelings of fatigue, nausea, and burning or aching pain.
But a little bit of discomfort is fine if you’re healthy and able to keep going. The muscle fibres sustain minor damage, which encourages them to grow back stronger and bigger. This is where the saying ‘no pain, no game’ comes from.
A healthy and balanced diet is essential for everyone at any given time of the day. Post-exercise food is particularly important as it is, in fact, the way to repair your body after a trauma.
Your workout is essentially a very stressful experience for your body and every time you engage in it, you are taking your body out of its comfort zone.
The meals that come after are meant to be the perfect substitute and a remedy for everything that has been lost in the process. While you could eat anything, or eat nothing at all, the purpose of the post-workout meal is to maximize the results.
So far, we have learned what happens to our bodies during the workout and the energy we lose in the process. It is now time to determine what we need to do to make up for the losses.
In order to renew your supply of glycogen, you need to consume about 0.5 to 0.7 grams of carbs per pound (it is roughly doubled per kilogram). If you are a person with high ambitions and you exercise multiple times a day, the fast recovery of glycogen is even more important.
The best carbs to consume are rice, leafy green vegetables, bananas, sweet potatoes, kiwi, berries, oatmeal, etc.
The purpose of the protein consumption after a workout is to repair the broken proteins in the muscle fibres damaged during the workout. Amino acids are key components for the repair.
Also, not only do the proteins boost muscle repair, but they also boost the growth of the muscle mass. You should consume 0.14 to 0.23 grams per pound of your weight. Eat lean protein appropriate for your dietary standards. (Keto probably requires slightly different macros – see below.)
If you do not eat meat or animal products you can find an adequate post workout protein powder or eat quinoa, tofu, hemp seeds, chickpeas, etc.
Most people see fats as bad food – and on a high-carb diet, they usually are. That’s because your body constantly burns glycogen, so it rarely gets to the fat-burning stage. Any excess fat is therefore stored in your body.
However, there are healthy fats you can eat which are in fact beneficial for your body, and if you’re doing keto, high quality fats are essential.
Consuming a small amount of fat after your workout will not necessarily diminish the effects of it. There was even a study conducted which showed that whole milk promotes muscle growth more than skimmed milk does.
If you’re doing keto, you’ll only need to load up on half the fat (weight for weight) as you would carbs. Each gram of fat provides 9 calories – which is quite a lot. Fat is also more satiating, because it’s quite rich.
The best fats are from nuts, seeds, oils and oily fish. A handful of nuts or some avocado guacamole are great sources of fat and essential nutrients.
Now, the question is: when is the right time to eat after a workout?
If you want to quickly take advantage of the window allowed for muscle growth, and recover your lost glycogen supplies, you should eat your workout meal within 45 mins. The meal should be a balanced combination of proteins, carbs, and fats, as stated above.
If you’re doing keto, you’ll probably want to tweak the numbers a bit (try this keto macros calculator).
The general advice is to eat carbs within 30 – 120 minutes after the training to make up for the lost glycogen. Proteins should be consumed as soon as possible. Looking at the middle ground, 45 minutes sounds just right.
Even though you probably enjoy working out, it is a stressful experience for your body. Consume the right portions of carbs, proteins, and fats to help your body recover and make the most out of your workout.