We still need to learn more about how to use vitamin D to improve sports performance but it does seem clear that obtaining sufficient vitamin D can only help improve an athlete’s bone structure, immune system, and potentially muscle health.

By Brittany Johnson
Last updated: February 29th, 2024
5 min read

Vitamin D: The ‘sunshine vitamin’ and muscle health

An afternoon lunch outside, a day at the beach, or simply getting some fresh air, you’ve likely heard someone say “I’m getting my vitamin D!” – or maybe you’ve said it?
Most people have heard our bodies can make vitamin D from the sun, but are we able to meet our daily needs from our afternoon sunbathing?  Vitamin D is best known for helping build and maintain bone structure, and increases the absorption of calcium, which is the main mineral found in bones. Chronic low vitamin D intake leads to poor bone development in children and weak bones in adults. This can cause osteoporosis, or brittle bones, meaning you’re more likely to have a bone fracture or break.

Vitamin D also plays a role in immune function, protein synthesis and muscle function, inflammatory response, and regulation of skeletal muscle.
Based on the functions of vitamin D, what might the specific roles of the vitamin be for athletes and sport performance? While a lot of factors limit the amount of sun exposure that is turned into vitamin D, there is quite a bit of evidence that this sunshine vitamin can help support healthy athletes. More on that later.

There are several complicated steps involved with turning sun rays into vitamin D in the body. I’ll spare you the details. But let me present to you the realistic side of using the sun as a primary source of vitamin D. First and foremost, UV sun rays are quite damaging to our skin and increase the chance of skin cancer, so lathering up with sunscreen is a great defence against this damage. However, when we wear sunscreen, it blocks the UV rays from penetrating our skin, and UV rays are required for us to then make vitamin D in the body. But UV rays increase skin cancer risk, so sunscreen is more important than getting our dose of Vitamin D from the sun!
Further, other factors that reduce our ability to make vitamin D from the sun include the time of day, seasons (e.g summer vs. winter), cloud coverage, smog, and skin melanin (darker skin colors make less vitamin D). So athletes who train mostly indoors won’t get as much sun exposure as athletes training outdoors. A great comparison would be ice hockey players (indoor, winter sport) and track and field athletes (outdoor, spring sport). Ice hockey players will have significantly less sun exposure from indoor  training or being covered in protective gear if playing outside. Whereas, track and field athletes will have higher sun exposure from training outdoors.

So, it looks like we need to turn to food for boosting vitamin D in athletes … although food sources might not be enough either. We will also discuss that later.

Types of vitamin D in our food

Two types of vitamin D are found in our food and supplements – D2 and D3. The only difference is the chemical structure, but both forms are absorbed. The presence of fat can enhance the absorption of vitamin D but some is still absorbed even without dietary fat.

Few foods naturally contain vitamin D but some which are high in vitamin D are fatty fish (salmon, tuna, mackerel), beef liver, egg yolks, and mushrooms. Other foods have been fortified (meaning food companies have added vitamin D) such as milk and orange juice. These foods provide the majority of vitamin D for individuals. But most people are not eating enough vitamin D-rich foods to meet our daily needs, putting many athletes into the deficient category.

How do we know if we have enough vitamin D?

Early signs indicating a vitamin D deficiency can be fatigue, bone pain, muscle weakness or cramps, and depression. A simple blood test can let you know if your sun exposure and diet is sufficient or not, and your physician can help determine how much vitamin D is needed for you personally.

In order to meet the daily requirements to maintain the blood levels of vitamin D, the global physicians and scientists of Endocrine Society suggest at least 25 mcg/1,000 IU per day. Those levels are quite hard to reach when consuming food, though – for example, one egg only provides 41 IU! Therefore, supplements are recommended for most individuals.

Current guidelines for the general public are the same for athletes with vitamin D levels, and more research is needed to determine if athletes require additional vitamin D.

Vitamin D and athletic performance

Now we have covered the basics of vitamin D, let’s dive into what is known about the potential role it plays in improving performance.

Overall it appears we still have a lot to learn about the sunshine vitamin, but indirect benefits of vitamin D are crucial to advance the health of athletes. The more the scientific world learns about vitamin D, we may soon have a better understanding that it goes beyond just helping absorb calcium.

Bone Health

Vitamin D is most commonly known for the benefits of improving bone health – it helps us absorb calcium, which improves overall bone growth and maintenance as we age. Stress fractures are common injuries in athletes and in active populations – studies have shown adequate vitamin D levels can reduce the risk of stress fractures, but individuals with lower levels had increased risk of stress fractures.

Immune Health

As an athlete, showing up to practice and games fully healthy is important for optimal performance. Vitamin D has been recognised as an immune-boosting vitamin, reducing sick time for athletes. Reducing sick days minimises lost training time which is important for game day. Not only does vitamin D improve immune health but it also decreases inflammation.

Muscle Health

Recent discoveries have identified vitamin D receptors located on our cells regulate muscle health and potentially strength. Some scientists believe vitamin D improves muscle strength because it assists with the role calcium plays in muscle contractions. However, this has only been observed in animals.

In research involving humans, muscle gains were not observed but fibre type changed in young men, leading scientists to believe vitamin D can improve the quality of muscle fibres. Other benefits have also been observed in vitamin D status and forearm strength in adolescent teens but this is based on correlation, not causation.

We still need to learn more about how to use vitamin D to improve sports performance. Based on what we currently know, obtaining sufficient vitamin D can only help improve an athlete’s bone structure, immune system, and potentially muscle health.

Vitamin D and athletic performance: Key takeaways

1. Vitamin D has many health benefits for athletes, including reducing sick days and stress factors
2. Vitamin D plays some role in muscle health and powering contractions
3. Assess your vitamin D levels with your primary care doctor to see if you need supplementation
4. Choose sunscreen and incorporate a vitamin D supplement into your routine as needed

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Brittany Johnson

Brittany is a Scientific Affairs Manager at GNC (General Nutrition Centers), reviewing scientific evidence supporting sport nutrition supplements. As a certified specialist in sports dietetics, Johnson’s primary focus is understanding how to best fuel athletes for optimising health and enhancing performance.

More content by Brittany

The post Vitamin D: How does it impact sports performance? appeared first on Science for Sport.

Contents

1. Plant based protein and performance
2. Types of vegan or vegetarian diet patterns
3. Protein quality: It’s not all about quantity
4. The importance of protein portions
5. Plant-based protein and sports performance
6. Can plant-based protein help you gain muscle?
7. Special considerations for plant-based athletes
8. Sources of protein: Key takeaways

Plant based protein and performance

A couple years ago, I was recruiting firefighters to participate in a health and wellness program that included nutrition and fitness coaching. Although this population is labelled as ‘athletes’ due to their physically demanding jobs, they have high rates of obesity, cardiovascular disease, and musculoskeletal injuries.

During my presentation, they were a captive audience and nutrition questions came in like wildfire (do you see what I did there?) – they wanted to know what the best diet was for losing weight and increasing muscle.

Around this same time, a popular documentary was released, bringing attention to a vegan diet as a cure-all eating pattern. Most questions were in relation to this very topic. Is a vegan diet the best for optimal health? Do vegan diets reduce chronic disease and obesity? Can athletes still maintain muscle gains following a vegan diet?

A handful of firefighters even began eating a vegan diet and the group wanted to know if it was the perfect option. According to this documentary, meat was out and plants were in, and firefighters and the public suddenly had a thirst for knowledge about vegan diets and began tossing the animal products away. Food companies even started creating more plant-based meat alternatives.

Firefighters choosing to follow a vegan diet was quite a controversial choice – some of their peers in the department were following carnivore diets (only eating animal products). Firefighters, at least here in the U.S., are traditionally known for meat cook-outs at the firehouse and eat together with their crews. Suddenly there was confusion about what vegans could consume for protein, and the main question became wanting to know if a vegan diet could increase muscle mass? The answer is not black and white.

But let’s backtrack a bit – you may not even know exactly what vegan means. Let’s start there and move to talking about powering sport performance with a plant-based diet.

Types of vegan or vegetarian diet patterns

There are several different types of eating patterns that fall under the category of vegan and vegetarian [1] diets. Individuals choose to follow these dietary patterns for a variety of reasons, such as ethical, environmental, or health. Here is a simple breakdown that explains the various vegetarian and vegan diets:

• Lacto-vegetarian: excludes meat, fish, poultry and eggs, as well as foods that contain them. Eats dairy products, such as milk, cheese, yogurt and butter
• Ovo-vegetarian: Diet excludes meat, poultry, seafood and dairy products, but eats eggs
• Lacto-ovo vegetarian: excludes meat, fish and poultry
• Pescatarian: excludes meat and poultry, dairy, and eggs, but allow fish
• Vegan: excludes meat, poultry, fish, eggs and dairy products — including animal-derivatives, such as gelatin (some don’t even eat honey)

Protein quality: It’s not all about quantity

Protein is important for athletes due to the physical demands of training on muscles – higher protein intake is required for athletes to support repairing and rebuilding muscle tissue through hypertrophy for performance.

But does the quality of our protein matter? More specifically, is the quality different whether it comes from an animal or plant? Again, this is not a black and white answer but cooking strategies can improve the quality of plant-based proteins.

Let’s first look at the fundamental basics of protein – amino acids are the building blocks of proteins in our food and body and they play a vital role in muscle health for athletes. In our food, there are 20 amino acids, and nine of these are considered essential, meaning our body doesn’t have the ability to make them.

Animal-based proteins are considered high-quality, or complete proteins, because they contain all nine essential amino acids. Whereas plant-based proteins are low-quality, or incomplete, because they are missing one or more essential amino acids. Plant-based proteins can become a moderate quality by combining complementary proteins, such as rice and beans – by combining the rice and beans, the amino acid profile is now complete.

Most important for our athletes is the consideration for the amino acids which play a significant role in fuelling muscles and recovery. Three essential amino acids are branch-chain amino acids (BCAAs): leucine, isoleucine, and valine, which are more concentrated in animal-based protein compared to plant protein.

BCAAs are particularly important for promoting muscle protein synthesis (MPS) – think muscle gains. These BCAAs are rapidly digested and considered ‘fast’ proteins. Fast proteins supply amino acids quickly after ingestion to stimulate muscle repair and begin building new muscle. Whey, a popular protein shake, is high in BCAAs and is a fast protein. Whey is filtered from cow’s milk, meaning it is a high-quality protein. Soy [2] is also considered a fast protein but does not stimulate the pathways to build muscle in the same way as whey. Soy is lower in leucine, an essential amino acid driving the anabolic response (building new muscle).

Animal-based foods, such as eggs, chicken, and milk have a higher concentration of BCAAs compared to plant-based sources like peas and soy. Following a vegan diet reduces the amount of BCAAs which help support muscle synthesis.

One last note about the differences between amino acids from animal and plant-based sources is the digestibility [3]. Plant proteins contain other properties that reduce our bodies’ ability to absorb the amino acids completely. However, during the cooking phase of plant proteins, the digestibility can be improved. Soaking, fermentation, and germination can reduce the level of properties reducing protein absorption. Even with the differences, vegetarians and vegans can meet their protein and amino acid daily needs.

The importance of protein portions

The Acceptable Macronutrient Range [4], which tells us how much protein should be consumed from our total calories, is 10-35%. Several factors influence where in this range an athlete should fall.

Because calorie intake varies day to day, we can calculate our daily protein needs based on our body weight (i.e. kilograms), depending on training level and mode of activity. Daily consumption should range from 1.4-2.0 grams per kilogram per day [4] – for example, an 80kg athlete should look to consume 112-160 grams of protein per day. Endurance athletes would be on the lower range, while strength athletes should be on the higher range.

For 1-2 days after physical activity, there is a prolonged anabolic effect [5], meaning a window of muscle growth. During this phase, a constant supply of amino acids is important to stimulate muscle gains. Therefore, incorporating protein at every meal is key to developing new muscle tissue.

The optimal amount of protein in a meal ranges from 20-40 grams [6], which stimulates MPS. Further evidence shows consuming whole food protein sources is more advantageous for MPS compared to isolated amino acids supplements. For example, consuming a whole egg containing protein, fat, vitamins and minerals, stimulates MPS greater than a protein supplement containing isolated amino acids.

Plant-based protein and sports performance

Protein intake before and after activity, as well as distributed throughout the day, is important to support training demands, muscle recovery, and building new muscle.

There is limited evidence on the specific sport performance benefits of following a vegetarian/vegan diet – the current available evidence [7] specific to sport performance, such as anaerobic and aerobic power, show no improvements in sport performance after following a vegetarian and vegan diet. It should be noted that choosing this type of eating pattern didn’t hinder performance, either. When athletes rated their level of perceived efforts in exercise [8], comparing a whey protein and rice protein supplement, there was no significant difference, meaning both groups were able to perform at adequate levels needed for sport.

With the little evidence available on sport performance, there appears to be no difference whether athletes choose to eat animal-based protein or plant-based protein.

Can plant-based protein help you gain muscle?

More research has explored plant-based protein and MPS than sport performance. Studies in active and non-active participants can help us begin to put the fire out when debating on the best diet for muscle gains.

When whey-based protein and soy-based protein supplements [9] were compared for the rate of MPS, both groups improved muscle mass following a 12-week resistance training program followed by a protein supplement (either whey or soy). The control group, or the group that did not receive any protein supplement after activity, did not have an increase in lean tissue.

Protein is important for muscle recovery, regardless of source, and both whey-based and soy-based protein supplements increased lean tissue compared to resistance training alone. This implies consumption of both types of proteins improves muscle mass.

Special considerations for plant-based athletes

Athletes who choose to follow a vegetarian or vegan diet will need to carefully plan their meals to ensure energy and nutrients needs are met. Data [10] tells us vegans tend to consume less calories than meat eaters, as well as lower amounts of protein, fat, vitamin B12, iron, and calcium. These nutrients support performance by meeting energy demands for physical activity, supplying oxygen to working muscles, and maintaining strong bones. Further, the amount of leucine intake should be considered for athletes following a plant-based diet to MPS [11].

Sources of protein: Key takeaways

Whether you follow a vegan diet or regular diet, both can meet daily protein needs to support performance. Athletes choosing to follow a vegan diet should consider supplementation of leucine, cook their protein to improve digestibility, and plan out meals to meet nutrient needs.

Here are some key takeaways:

1. Both plant-based and animal-based protein support MPS
2. Distribute protein intake throughout the day – strive for 20-40 grams per meal
3. There are no sport performance benefits or decreases from consuming a vegetarian or vegan diet
4. Vegetarians and vegans should plan their meals to meet specific nutrient needs

[optin-monster-shortcode id=”czosk0qsqzzsryj6gwot”]

Brittany Johnson

Brittany is a Scientific Affairs Manager at GNC (General Nutrition Centers), reviewing scientific evidence supporting sport nutrition supplements. As a certified specialist in sports dietetics, Johnson’s primary focus is understanding how to best fuel athletes for optimising health and enhancing performance.

More content by Brittany

The post Can plant based protein boost your muscle health? appeared first on Science for Sport.

Beyond the well-documented health benefits of Omega-3s, they can also play an important role in muscle strength, endurance, recovery, and injury prevention for athletes.

By Brittany Johnson
Last updated: March 1st, 2024
4 min read

Omega-3s – why fats shouldn’t be feared

You’ve likely heard about Omega-3 fatty acids, but do you know why they are the talk of the town in nutrition circles? Omega-3s are groups of fatty acids (fat) found in our food and are the true ‘alphas’ of fat for performance. Why? Let’s find out …

Fat is an important macronutrient for athletes to meet calorie demands, prevent using protein for energy, and help with recovery. Fats in our food are either saturated or unsaturated based on the structure of the fatty acid – an easy rule to remember is saturated fat is found primarily in animal-based foods, with the exception of palm and coconut oil, and unsaturated fat is found primarily in plant-based foods, with the exception of fatty fish (e.g., salmon).

There are many types of unsaturated fats, but two commonly known are Omega-3 and Omega-6 fatty acids. Most people get plenty of Omega-6 in their diet but not nearly enough Omega-3. Foods rich in Omega-6 include mostly vegetable oils, commonly found in highly processed foods. Omega-3 rich foods include fatty fish, olive oil, walnuts, chia seeds, and flax seeds but they are typically inadequate in most daily diets, especially if consuming fatty fish is not part of your weekly intake.

There are three types of Omega-3 fatty acids found in food: Alpha Linolenic Acids (ALA), Eicosapentaenoic Acid (EPA), and Docosahexaenoic Acid (DHA). ALA is an essential fatty acid (meaning our bodies do not make it) but the research showing Omega-3s as the true alphas of health benefits and performance focuses on EPA and DHA. So, let’s talk about those performance benefits…

Potential benefits of Omega-3 for athletic performance

Beyond the well-documented health benefits of Omega-3s — including heart health, weight management, and blood sugar control — Omega-3s play an important role in muscle strength, endurance, recovery, and injury prevention for athletes.

OMEGA-3 FOR STRENGTH
Studies have shown Omega-3s boost muscle protein synthesis, which increases muscle mass and strength. The research suggests Omega-3s, specifically EPA, improves protein metabolism. Further, recent research demonstrates Omega-3s prevent the loss of muscle mass, meaning if you’ve sustained an injury and want to maintain muscle mass, adding Omega-3s could be a dietary tool to help maintain your body composition during healing.

Improving muscular strength requires a higher load of training and additional caloric intake to gain muscle mass, and Omega-3s contribute to this by adding daily calories to replenish your training calorie deficits. Fats contain nine calories per gram compared to four calories per gram in carbohydrates and protein. Therefore, fat is more calorically dense, allowing athletes to fuel up and meet higher caloric requirements to build muscle.

OMEGA-3 FOR ENDURANCE
Few studies have examined how Omega-3s improve endurance, however, some evidence suggests ingestion of Omega-3s can improve endurance capacity. Omega-3s act as a vasodilator, increasing oxygen flow during exercise, which increases endurance. Other studies show higher Omega-3 consumption reduces fatigue. While there are limited studies on endurance training, there is some evidence that supports Omega-3s’ potential for improving endurance.

OMEGA-3 FOR RECOVERY
Omega-3s contain anti-inflammatory properties which aid in muscle recovery and injury prevention. Consuming higher Omega-3s improves the integrity of your cells and cellular function, ultimately reducing muscular damage. Just seven days of supplementation can decrease post-exercise muscle damage and soreness.  Additionally, Omega-3s have been shown to improve sleep, which is a vital piece of the puzzle for performance recovery .

In conclusion, it appears Omega-3s can help athletic performance by improving muscle strength, endurance, and reducing recovery time.

Omega-3 rich foods to include in your diet

ALA is found in plant-based nuts, seeds, and oils. EPA and DHA are found in fatty fish and marine algae. Therefore, it’s recommended to consume two servings per week of low-mercury fatty fish such as salmon, sardines or herring to meet 500mg per day of EPA and DHA. Generally, smaller fish have lower mercury content than larger fish, and wild fish have more Omega-3s than farm-raised fish.

What about Omega-3 supplements? 

If needed, supplements can be taken, since most people do not consume two servings per week. When looking for supplementation, consider the level of Omega-3s you are currently consuming and dose accordingly. The National Academy of Medicine suggests a daily consumption of 1.6 g for males (ages 19-50), and 1.1 g for females (ages 19-50). Find a USP-approved label, which means a third party tested the accuracy of the product.

These supplements are found in many grocery stores at reasonable prices, yet be cautious of buying the cheapest brand. Check the label for the level of EPA and DHA- the most important Omega-3 fatty acids.

Omega-3s: Key Takeaways

1. Omega-3s can improve athletic performance by increasing muscle strength, endurance, and recovery
2. Choose Omega-3 fats for health and performance benefits by incorporating more olive oil, walnuts, chia seeds, and flaxseeds
3. Aim to consume at least two servings of fatty fish per week
4. Consider supplementation as needed to reach the recommended levels, as per the above National Academy of Medicine recommendations.

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Brittany Johnson

Brittany is a Scientific Affairs Manager at GNC (General Nutrition Centers), reviewing scientific evidence supporting sport nutrition supplements. As a certified specialist in sports dietetics, Johnson’s primary focus is understanding how to best fuel athletes for optimising health and enhancing performance.

More content by Brittany

The post Omega-3s: Why they are the real Alphas of fat for athletic performance appeared first on Science for Sport.

Having a basic understanding of how carbohydrates are used during exercise can take your training and performance to the next level, and carb loading is a piece of the puzzle

By Brittany Johnson
Last updated: February 29th, 2024
6 min read

Carbohydrates – to load or not to load?

Back in high school, my water polo team hosted spaghetti nights, where the team would load up on carbohydrates the night before a big game. Maybe you’ve had spaghetti nights of your own, or perhaps heard of carbohydrate loading somewhere along the way, but is it still the best practice?
Having a basic understanding of how carbohydrates are used during exercise can take your training and performance to the next level, and carb loading is a piece of the puzzle. Let’s start by defining carbohydrates, then discuss how the body uses carbohydrates during exercise and explore what the research says about carb loading for performance.

Types of Carbohydrates

Carbohydrates are found in grains (e.g., oatmeal, farro, barley, quinoa), fruit (e.g., whole fruits and fruit juice), milk, beans, starchy vegetables (e.g., potatoes, peas, and corn), sweets (e.g., cakes, cookies, candy), and sugary beverages.

There are two main types of carbohydrates when we think practically: simple and complex. Simple carbohydrates are foods lacking fibre, such as fruit juice and sweets. Complex carbohydrates contain fibre, such as oatmeal and whole fruit. Carbohydrates are rated on a scale called the glycemic index (GI), which represents how quickly a carbohydrate-containing food increases blood sugar levels after ingestion. Low glycemic foods include green vegetables, most fruits, beans and whole grains. High glycemic foods include white rice, white breads, and white potatoes. For health benefits, such as reducing the risk of Type 2 Diabetes, our diets should contain mostly complex/low GI carbohydrates. However, in some cases, such as playing sports or exercising, choosing simple carbohydrates/high GI foods is more optimal. We will discuss that in the next section.

What’s the science on carb loading (aka – eating that plate of pasta)?

The concept of carb loading aims to increase the stored muscle glycogen in an effort to prolong endurance and/or improve performance. Low glycogen training has been shown to negatively impact exercise intensity in both anaerobic (doesn’t need oxygen to produce energy, e.g. resistance training) and aerobic (needs oxygen to produce energy, e.g. endurance training) exercise. Maximising glycogen stores can reduce fatigue during both anaerobic and aerobic exercise. However, most of the promising research shows results in aerobic, endurance-based activities.

Carb loading for short-duration activity
Very few studies have investigated the impact of carb loading on short-duration anaerobic performance. A study in male basketball players found no difference in peak power after seven days of carb loading following a four-week low carbohydrate diet. While carbohydrate loading didn’t produce higher peak power, the results from the study have implications for the importance of adequate glucose availability. After following the four-week low carbohydrate diet, the players’ performance decreased. However, after seven days of carbohydrate loading and replenishing glycogen storage, peak power returned to baseline. This means carbohydrate loading following a four-week low carb diet is effective at recovering baseline anaerobic power, emphasising the importance of glucose availability for optimal performance. Another research study looked at the impact of carb loading on jump squat power and found no improvement. So, we can conclude carb loading is not necessary for anaerobic, short-duration exercise but the amount of glucose available at the start of an activity is an important factor.

Carb loading for long-duration activity
The effects of carbohydrate loading on long-duration endurance exercise have garnered much more attention in the research world. However, the results differ depending on the event distance/duration and population studied. It’s been found that after an 80-minute rugby game, glycogen stores are no different in players who carb-load for 36-hours before the game to players who don’t. In other research based on individual running race times, carbohydrate loading failed to improve times for 10km and 25km treadmill runs. However, carbohydrate loading prior to a 30km cross-country run and a 30km treadmill run limited fatigue in well-trained athletes. Therefore, carbohydrate loading extends the time to glycogen depletion in running events longer than 30 km, ultimately allowing athletes to maintain race speed for a longer duration and improve race times. It appears endurance activities greater than 90 minutes support the practice of carbohydrate loading as an effective strategy to improve performance and exercise capacity.

Gender differences
There appears to be some discrepancies between women and men using glycogen stores during activity. Women tend to have lower resting muscle glycogen concentrations, which can impact the benefits of carbohydrate loading. Research has shown large differences in these benefits when comparing males and females. When both sexes followed a high carbohydrate diet (~75% of calories from carbohydrate foods), cycling performance increased by 45% in males and only 5% in females. Further, males managed to increase their glycogen stores by 41%, while there were no changes among females.

Knowing this, it may be beneficial for women to increase total calorie and carbohydrate ingestion during the loading phase to maximise glycogen stores.

Other considerations

An important factor to consider for carbohydrate utilisation during endurance exercise is the glycogen availability beforehand. Skeletal muscle has the ability to increase the amount of glycogen stores through training and diet. However, this does not happen overnight and needs 24-48 hours of high carbohydrate intake to occur.

While carb loading tends to favour performance benefits for endurance events greater than 90 minutes, it is just one dietary manipulation method in the tool kit for athletes. Athletes should plan their carbohydrate intake based on sport-specific and goal-specific outcomes. Overall carbohydrate intake is important pre-, post-, and possibly during (events lasting longer than 60 minutes) physical activity.

Another benefit of adequate glycogen availability for endurance exercise is improved skeletal muscle repair and recovery. Higher glycogen stores improve post-exercise muscle recovery. So, not only will that extra serving of spaghetti help you tick off that bucket list item of running a marathon, but it will aid in your recovery afterward, too – and you’ll need all the help you can get!

Summing up the pros and cons of carbs

The current research doesn’t have a clear answer, but promising results appear to benefit endurance exercise greater than 30km distances. Different results are likely contributed to small sample sizes, sport-specification, and population (e.g. highly trained athletes/males). Further, protocols for carbohydrate loading differ in research and practice. In most practices from our sport teams growing up, carb loading took place one night before the event, whereas research protocols vary, with seven days of carb loading and tapering training sessions (gradually reducing the amount of training) for 24-48 hours leading up to the event. Maybe we should have a week of spaghetti nights instead of one night before to increase glycogen concentrations more effectively! More seriously, conclusions drawn from the research imply carb loading is only one piece of the dietary puzzle that can advance performance for endurance athletes.

So, what are the practical applications for increasing glycogen storage?
The recommended dose for higher carbohydrate intake is 8-12 grams per kilogram of body weight. For example, an athlete who weighs 85kg should consume around 680-850 grams of carbohydrates. Consuming high GI foods appears to promote an increase in glycogen stores in athletes. The most important factor for carbohydrate loading is meeting the overall daily individual carbohydrate needs.

Carb loading timing strategies to increase the amount of glycogen stores include:

1.     Exercise resulting in exhaustion followed by several days of high carbohydrate intake
2.     An exercise taper combined with several days of increased carbohydrate intake
3.     A 24-48-hour high carbohydrate intake for trained athletes

While carb loading can be an effective strategy to improve your endurance performance, a holistic approach to carbohydrate availability is most important.

Key takeaways

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Brittany Johnson

Brittany is a Scientific Affairs Manager at GNC (General Nutrition Centers), reviewing scientific evidence supporting sport nutrition supplements. As a certified specialist in sports dietetics, Johnson’s primary focus is understanding how to best fuel athletes for optimising health and enhancing performance.

More content by Brittany

The post Carbohydrate loading for endurance – still a good practice? appeared first on Science for Sport.