Proper post-workout nutrition is essential for those interested in increasing lean body mass, losing weight and achieving their fitness goals. For those new to fitness, you may find yourself in a nutritional supplement store surrounded by hundreds of different options that ensure you will become a lean machine. It will empty your bank account at the same time too. Instead of going through all the different supplement options on the market, I will discuss what the current research shows regarding ingesting protein and carbohydrates post-workout for both weightlifters and endurance athletes.

Proteins and carbohydrates serve different purposes when ingested in the body.

When ingested, carbohydrates are transported as glucose molecules by insulin which is utilized as an immediate source of energy by the brain and muscle tissue (1). Insulin is considered an anabolic (muscle building) hormone since it is responsible for transporting carbohydrates and amino acids into muscle cells which initiates protein synthesis and muscle repair (2). Whatever carbohydrate is left over it is stored as glycogen in muscle tissue and the liver (1). It is important to closely regulate the number of carbohydrates ingested because once the optimal levels of muscle and liver glycogen levels are reached the body converts excess carbohydrates to fat through a process called de novo lipogenesis (3). During this process, glucose molecules are converted and stored as fat which can lead to weight gain when consumed in excess.

When more energy is required, glycogen is broken down from their storage sites in the liver and muscle.

It is utilized as the bodies primary fuel source. Fatty acids are also a major fuel source for light to moderate intensity and long duration activities (4). In the absence of glycogen or carbohydrate intake, gluconeogenesis occurs which allows the body to create glucose from non-carbohydrate sources such as amino acids. This is commonly referred to as a protein (5). It allows the body to regulate energy levels in the absence of carbohydrates but can have a negative effect on muscle tissue since it puts it in a catabolic state or muscle breakdown.

For athletes who perform long duration, low-intensity exercise, they can deplete their carbohydrate stores within 90-120 minutes (6).

At this point, the body utilizes a greater percentage of fats and proteins as an energy source which places the body in a catabolic state meaning it breaks down muscle tissue for energy. Therefore, it is essential for endurance athletes to ingest carbohydrate supplementation either during or immediately following their event in order to avoid protein breakdown and muscle loss. It has also been suggested that higher intensity training such as HIIT training can deplete glycogen levels within 20-30 minutes (6). For endurance athletes, there has been evidence suggesting consuming 3-4 grams of carbohydrates for every 1 gram of protein ingested in order to promote glycogen synthesis within the body and prevent protein breakdown.

Typically, people who perform resistance training do not need to ingest an increased amount of carbohydrates post workout(8).

For many years it had been suggested that ingesting a combination of carbohydrates and protein following resistance training was essential for increasing lean muscle tissue and to promote muscle hypertrophy due to the increased insulin response from ingesting carbohydrates. However, several research studies have concluded that the insulin response from amino acids alone is sufficient to promote muscle repair (8). Also, there were no significant changes in strength gains or muscle hypertrophy when comparing individuals who consumed only amino acids post-treatment versus a combination of carbohydrates and protein (9). The research did suggest that additional research in the area is needed to make substantial claims, but the current evidence does not suggest that a combination of carbohydrates and protein ingestion is more effective than protein ingesting alone for people who perform resistance training.

Ingesting carbohydrates and amino acids post-workout is essential for long duration workouts performed by endurance athletes who are training for 90+ minutes at a time to prevent muscle catabolism (protein breakdown) and to effectively replenish their energy stores for their next workout. However, additional carbohydrate supplementation has not been concluded to be beneficial for those completing resistance training alone since the carbohydrate and fat stores are sufficient to fuel the body and prevent muscle breakdown. For those who perform resistance training, ingesting additional protein alone has been shown to be effective in promoting muscle hypertrophy and muscle repair.

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References

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224210/
  2. https://www.ncbi.nlm.nih.gov/pubmed/16705065
  3. https://examine.com/nutrition/how-are-carbohydrates-converted-into-fat-deposits/
  4. https://riordanclinic.org/2012/04/fuel-sources-during-exercise/
  5. https://www.ncbi.nlm.nih.gov/books/NBK22591/
  6. https://8fit.com/fitness/glycogen-depletion-signs-symptoms-and-working-out/
  7. https://www.ncbi.nlm.nih.gov/pubmed/18834505
  8. https://breakingmuscle.com/fuel/carbs-and-protein-do-we-need-both-after-a-workout
  9. https://jissn.biomedcentral.com/articles/10.1186/1550-2783-10-42

There is a lot of information out today about how much and what kind of sugar we should be eating. Add that to the overwhelming array of sweetening products and it’s hard to know what to choose. So, to get an idea of what’s out there and what might be best for you, let’s start with understanding…

The Basics:

Carbohydrates are an immediate source of energy for your body and provide the fuel for your muscles and organs, such as your brain. There are two basic types of carbohydrates:

  • Simple-These are mainly found in fruit juice along with processed foods and anything with added refined sugar such as soft drinks or candy. You can think of this as the ‘white’ granulated sugar that you bake with. The body can easily digest these.
  • Complex-These are found in nearly all plant-based foods and usually take longer for the body to digest. They can be found in whole-grains, fruits and vegetables.

The Role:

Carbohydrates provide the cells in your body with the energy they need for everyday, whether it be your brain functioning, your heart pumping or physical exercise.

The Amount:

Sadly to say, there is no exact magical or scientific number that I can give you. It is recommended that 40-60% of your calories per day come from carbohydrates, the more complex, with vegetables and whole grains, the better.  A few key points to consider:

  • When you eat foods that contain too many carbohydrates in one sitting the carbohydrates are then stored in the liver and muscle cells. Your body uses these when you need an extra burst of energy. But your muscles and liver can only store so much.
  • Anything left over that your body doesn’t have room for in the liver and muscles is turned into fat.
  • Once it is turned into fat, your body cannot change it back into a carbohydrate.

Problems linked to high intake of sugar:

The average American consumes about 400 calories per day from added sugars which are also known as simple sugars; soda, candy, dessert, processed food, etc. and in the medical field we are seeing the affects of this culture. It is recommended that no more than 100-150 calories per day be from added sugar, which is about 32 grams or 8 teaspoons. Problems linked to extra-added simple sugars in the diet are:

  1. Insulin Resistance
  2. Increased Caloric Intake
  3. High Blood Pressure
  4. High Triglycerides and Cholesterol
  5. Decreased intake of essential vitamins, minerals and fiber.
  6. Obesity

How will I know if I am not eating enough?

If you are not eating enough carbohydrates you will experience fatigue, muscle cramping and poor mental function; among other things. Fatigue is usually the first to set in and is seen especially when a person fasts, this can interfere with daily activities. Carbohydrates are your body’s first choice for fuel. A low carbohydrate diet may seem healthy, but if taken to the extreme it is very dangerous and can affect brain function. Remember, if you choose a low carbohydrate diet, it means LOW in carbohydrates, not NO carbohydrates.

What about calorie-free or low-calorie sweeteners?

The best choices for sweet foods are foods with complex carbohydrates, plant-based foods that contain fiber in them. Fruits.  Personally, when I bake, I would rather use the right amount of sugar and then only eat one rather than eating the entire batch, it is all about self-control. The biggest concern with artificial sweeteners is that they have not been out on the market very long for scientists to be able to study the long-term affects to your bodies. The other issue is that the studies that have been performed contain a lot of biased because the company making the product employs the scientists that study the product. With that said, here are a few low-calorie sweeteners options. I do not promote these, but they are very popular and clients deserve to be given the option.

SweetLeaf Sweetener and Truvia

Both of these products are made from the stevia herb. SweetLeaf contains only stevia and Truvia contains stevia and a sugar alcohol. These both contain zero calories and according to their websites can be used for baking. The Food and Drug Administration (FDA) has deemed stevia safe in moderate amounts and is now added to many different beverage options. PepsiCo as developed its own version known as PureVia.

Whey Low

This is a blend of fructose, sucrose and lactose and completely absorbed in the body. Since the body can absorb this product it has 5 calories/teaspoon. Many repost using Whey Low and substitution in baking works well, but be sure to go their website for the ratio and the change in oven temperature. There is no statement by the FDA, and according to their website there are no side effects observed in testing performed to date.

Xylitol

This is a natural sugar alcohol found in a few different foods; the human body also naturally produces it during digestion. Xylitol tastes sweet like sugar, but had 40% less calories than sugar. It is absorbed slowly, which in turn does not stimulate insulin or an increase in blood sugar. The FDA deemed xylitol safe for human digestion in 1986, however, in large amounts xylitol could result in abdominal discomfort, gas and diarrhea.

Agave Nectar

Agave is produced from desert plants and is a liquid sweetener that actually contains more calories than sugar, 20 calories/teaspoon compared to 15 calories/teaspoon for sugar. However, agave is so sweet that much less is needed to reach the same sweetness as sugar. Agave is mainly used in making beverages and is considered safe for consumption in moderate amounts, but some experts state that pregnant women should use with caution because it may contain steroids that could lead to a miscarriage. The high-fructose content of agave nectar is of some concern as people believe an increased consumption of fructose is to blame for part of America’s obesity epidemic.

What about the sweeteners you see are on every restaurant table?

These sweeteners are found is a lot of foods: soda, yogurt and even some breakfast cereals. While they are FDA approved and used regularly, many people wonder about their safety. Based on research these show little or no harm when used in moderation. The FDA has a list of sugar substitutes recommended by the American Heart Association and the American Diabetes Association along with an acceptable daily intake (ADI).

Name Example ADI per day Additional Information
Aspartame(blue packet) Equal 1 packet for every 3 pounds of body weight Use with caution for people with phenylketonuria
Saccharin(pink packet) Sweet’N Low 1 packet for every 5 pounds of body weight Can cross the placenta during pregnancy
Sucralose(yellow packet) Splenda 1 packet for every 5 pounds of body weight Can be used for baking

These sweeteners are 160-13,000 times sweeter than sugar, which in turn means that you need to use a lot less than sugar to obtain the same sweetness and you consume a fraction of the calories than the same amount used of sugar. This does not always mean that the foods are low in calories or fat, and eating too many reduced-sugar foods can lead to actually eating more calories than necessary. Remember; don’t ever replace fruits and vegetables with these products, you will miss out on many important nutrients. According to the National Cancer Institute’s Cancer facts, there is no epidemiological study that provides clear evidence to link sugar substitutes to cancer. Typically the normal levels that adults use show no evidence for health issues.

Remember, the best sweeteners are those that are natural and are not made in a scientist’s lab. When it comes to sugar intake, if you stick to mainly complex carbohydrates, like fruits, your body will thank you.