Masterclass: Nutrition and Supplementation
We all know how important exercise is for our body for our health and wellbeing. However, it is equally as important to make sure that we are fuelling our body with the right nutritious foods and beverages to provide our bodies with enough energy to be able to sustain efforts of physical activity.
Eating a balanced diet is essential for absorbing the right number of calories and nutrients that is necessary for any daily activities as well as regular exercise.
This article will cover a range of different topics relating to nutrition including a summary of the different macronutrients in food and how they provide energy, tips for eating well, eating for body composition, as well as nutrition for pre, during and post exercise.
Carbs, Protein and Fats:
The basic elements of a diet include vitamins, minerals and nutrients as well as macronutrients which is what we will be looking at in this article.
Macronutrients are the nutritional compounds that provide your body with the energy needed to perform daily activities as well as physical activity.
The three Macronutrients are Carbohydrates (CHO), Protein (CHON) and Fat. Each of these macronutrients play an important role in providing energy to your body in different ways.
The general composition of macronutrients in an average person’s diet is 55% CHO, 15% CHON, and 30% fat compared to that of an athlete which is 60% CHO, 15-20% CHON and 20-30% fat.
With that lets get into the specifics of each type of macronutrient and see what they do!
Carbohydrates:
Carbs are sugars and starches found in food that are then converted into glucose when consumed. Carbs are processed and absorbed as glucose and subsequently, blood glucose increases and is transported around the body for use energy.
In the absence of physical activity when glucose isn’t needed, insulin levels increase and promote the storage of glucose in the muscle and liver as glycogen. Glycogen can then be converted quickly into energy when the body requires it.
Carbs provide the major source of energy during high intensity physical activity.
So how much of it do we store in our body? A total of 350g-500g of glycogen is stored in our bodies at all times when a quick burst of energy is required. 300g-400g of that total is stored as muscle glycogen, 50g-100g is stored as liver glycogen and 5g is stored as blood glucose.
What happened when we “run out”? We are never truly depleted of glycogen as the body has processes in place to continue to produce it however these processes aren’t as quick and sufficient. Instead, fat then becomes the predominate fuel source for continued activity.
Protein:
Proteins are major the major structural component of all body tissue. Proteins are a sequence of amino acids in a polypeptide chain. There are 20 different amino acids that your body needs, however your body cannot synthesise 8 of the 20. We have to consume food that contain the 8 essential amino acids through food.
There two different categories of proteins. The first are “complete proteins”. These are foods containing all essential amino acids in the right quantity and ratio to allow tissue growth such as meat, fish, poultry and eggs. The other category is “incomplete proteins”. These proteins are foods lacking one or more of the essential amino acids.
Protein has many different roles to play such as muscular growth and repair, enzyme regulation, red blood cell production, as well as acting as a source of energy when carbs and fats aren’t available.
Fats:
Fats are the body’s preferred fuel for daily activity and/or low intensity activity. There are two common categories of fats that you would have heard of: saturated fat and unsaturated fat. Saturated fats are fats that increase your low-density lipoproteins (LDL) also known as “bad cholesterol”. They are commonly associated with animal fats. You want to limit your consumption of saturated fats as much as possible to about 10% of your total fat intake.
Unsaturated fats on the other hand can be broken down even further to Monounsaturated and polyunsaturated fats. Monounsaturated fats can lower LDL and increase your high-density lipoproteins (HDL) also known as “good cholesterol”. Examples of foods high in monounsaturated fats include plant-based liquid oils such as olive oil, canola oil, avocados, nuts and seeds. Polyunsaturated fats can help to lower or maintain LDL and is found in plant and animal foods, such as salmon, vegetable oils, and some nuts and seeds.
Tips for Eating Well:
Eating regularly is essential for weight control, and especially fat loss
Important to aim for a regular eating pattern of meals, or meal and mid-meals
Don't skip breakfast; skippers are more likely to be tempted by unplanned discretionary choices during the morning
Regular breakfast eaters who have breakfast based on wholegrain cereal or bread, low fat milk or yoghurt and some fruit and veggies
· Eat with other people not TV; people who eat with others and eat at the dining table are more likely to eat regularly and eat well.
In the current situation we find ourselves in, it is important to keep up our social distancing practices. You may be in self isolation and are unable to physically be present with family members and friends. It's a good idea to plan Facetime, Skype, Zoom catchups with friends and family for dinners, lunches, coffee breaks etc.
Snack smart; limit eating foods with empty calories (no nutrients), instead opt for a piece of fruit, low-fat yoghurt, nuts, carrot and celery sticks etc.
Choose foods with healthy fats; limit consumption of saturated fats and avoid foods that contain trans fats
Veggies and Fruit; go for colour and variety!
Healthier choices for eating at home:
Plan meals around fresh veggies (frozen and tinned veggies are okay, check salt content)
Choose wholegrain bread, pasta, rices etc.
Opt for small servings of lean meats, fish and poultry. Limit consumption of processed meats like salami, ham, bacon etc.
Drink plenty of water with meals and during the day
Cook meals in large batches and freeze the leftovers for lunches/dinners
Plan ahead to save time and money; e.g. create a fortnightly menu
Use minimal oil when pan frying meats, veggies etc
Opt for tomato-based sauces over creamy ones
Lessen the amount of salt you add whilst cooking
Healthy eating doesn’t mean expensive!
Cook extra for evening meal to use leftovers as lunch or dinner the next day
Cook double amounts of meals and freeze the excess meals
Keep an eye out for supermarket specials
The Australian Department of Health and State Departments of Health have many resources that are accessible and easy to understand.
Here is an easy and relatively cheap recipe that you can try at home! Follow along and enjoy!
Get the recipe here.
Eating for Body Composition
Fat Loss
The prevalence of obesity has more than doubled in the past 20 years in Australia. Overweight and obesity affects ~63% of Australian adults and ~23% of children and adolescents. Approximately 70% of men and of women in Australia are either overweight or obese.
The good news is that weight/fat loss decreases mortality however this change must be permanent as fluctuating weight may increase that risk.
The key to weight loss is to create an energy imbalance! You want to lessen your energy intake (calorie consumption) and increase your energy expenditure (exercise!). An extra 420kJ consumed per day (e.g. one sweet biscuit or glass of beer) can result in more than a 3kg gain over one year!
Your body will burn energy throughout the entire day, however when you compare an hour of walking (~1200kJ expenditure) to an hour of sitting (350kJ expenditure), you know which one you would rather do.
Aligning with the Australian Dietary Guidelines, to achieve and maintain a healthy weight you need to be physically active and choose amounts of nutritious food and drinks to meet your energy needs.
So, what about dieting? What is the best diet to go on if you want to achieve fat loss? The answer? The type of diet makes little difference, it is more about eating less kilojoules and is best to achieve this in the 'healthiest' way possible!
A sensible eating plan should involve balanced nutrition (lots of variety) and mostly normal foodstuffs. It should also decrease your current intake to no less than 5000-6000kJ per day and should be followed long term. However, make sure you gradually lessen your caloric intake as sudden changes can occasionally “shock” your body. Cut down on your fat intake to only 40-50g per day, choose low-joule drinks, cut down on your sugar intake by limiting empty calories (food that provides little to no nutritional value at all), choose healthy snacks like fruit and nuts etc. These are all some ways that you can alter your diet for the better.
Diet and exercise = the best combination; why?
Changes can be more MILD
Increased daily kJ expenditure, so "spartan" diets not needed
Increase Basal Metabolic Rate
Increase muscle mass
Increase appetite regulation
Increase fitness, decrease stress, decrease coronary risk
Increase chance of long-term success
Pre, During and Post Exercise Nutrition Strategies for Athletes
Pre-Exercise
Immediate Pre-Exercise Carbohydrate intake:
Day of Competition/Event
Pre-event meal (2-4 hours prior to event)
CHO intake of 200-300 g in the 2-4 h pre-exercise has been shown to prolong cycling time to fatigue
What is the importance of the pre-event meal? Your liver glycogen stores are labile (changes status rapidly) so the pre-event meal works as a top-up for those stores.
Athletes may need to take considerations when having their pre-event meal. The timing of this meal may interfere with the event itself, for example triathlons commonly commence at 6:30am. The athlete would then need to think about the other things that timing can affect like sleep, travel time etc.
What type of carbohydrates should athletes eat? If you think about it logically, an endurance athlete would want to consume low GI foods as they slowly release energy compared to high GI foods. GI is an index of how quickly different carbs can be digested and absorbed. Examples of low GI foods include oats, wholegrain pasta/bread, beans, fruit etc. Examples of high GI foods include potatoes, white bread and short-grain rice.
During Exercise
For exercise over 60 minutes in duration, there should be a carbohydrate intake of 30-60g per hour. The most common way to ingest carbs during exercise is generally in a liquid form. For example, CarboShotz contains 30g of carbs per serve and Gatorade contains 36g of carbs per 600mL.
How does consuming carbohydrates during exercise help an athlete’s performance? It increases their plasma glucose as well as their carbohydrate oxidation.
So why would an athlete only consume a max of 60g of carbs per hour? Carbohydrates are oxidised at a maximal rate of 1g per minute even when they are consumed excessively.
There is evidence to suggest that perhaps mixing carbohydrate types (i.e. glucose and fructose) could potentially increase the oxidation rate of carbs as they are absorbed by different glucose transporters in the gut.
Post-Exercise
Glycogen resynthesis begins immediately post-workout. An athlete’s post-exercise carbohydrate consumption should occur within a short window after they’ve finished exercising to accelerate the resynthesis process.
What about post-exercise protein intake? Protein is essential for helping the muscles repair themselves from the breakdown that just incurred during exercise. The average amount of protein to consume post-exercise is 20g or 0.3g/kg. Typically, you would want to consume protein within 30 minutes of finishing the exercise. There are numerous commercially available protein powders you can purchase however if you’re on a budget, a bowl of cereal with milk will provide you with a good amount of protein and carbs!
Supplements
People have different reasons for taking supplements. They might take supplements to help prepare the body for exercise, reduce the chance of injury during training, or assist with recovery after exercise. Performance supplements cannot substitute for a healthy diet, but some of them may have value, depending on the type and intensity of your activity.
Protein Powders
Are protein powders really beneficial? Like stated earlier, 20g of protein is enough post-workout to supply your body with the necessary amount to help the muscles repair themselves. Cost-wise many protein powders can be on the expensive side. For example, a $29/kg commercial product contains 20.1g of protein per 50g of powder. If you compare that to skim milk powder that you can purchase from the supermarket for around $8.75/kg, it contains 17.6g of protein per 50g of powder. Skim milk powder is just as good AND cheaper compared to commercial protein powders. However, some protein powers may ensure that all essential amino acids are obtained in the product, can provide adequate protein to repair and maintain muscle mass, and act as a supplement isolate which can avoid co-digestion issues.
Iron
Iron is found everywhere throughout the body. It plays a key role in many bodily functions like oxygen transport, energy metabolism, brain function, immune function and is a key process in sustaining physical activity.
The body contains approximately 3-5g of iron and 1-2g of that is lost daily. The recommended daily intake of iron is different for men and women. Males require 8mg/day and females require 18mg/day.
It is common for athletes to develop an iron deficiency as they are exercising in high quantities. There are three high risk groups: female athletes, distance runners, vegetarians/vegans. Approximately 25-30% of female athletes are reported to have an iron deficit and ~10% of male athletes. Why are these stats so high? There are numerous avenues of iron loss during exercise: poor nutrition, urine, sweating, red blood cell destruction etc.
There are three ways in which an athlete can increase their iron intake. Increasing iron consumed in the diet, oral iron supplementation, intramuscular injections/IV infusion. The
decision for a person to take iron supplementation will be made based on haematological data.
Ergogenic Aids
Ergogenic aids are any external influences determined to enhance performance. These include nutritional and pharmacological products but might also be mechanical aids.
There is strong evidence to suggest a positive and safe ergogenic potential with caffeine, creatine, nitrate, and beta-alanine. Each of these evidence-based performance supplements can be found on the supermarket shelf.
Caffeine can be pretty straight forward. When you think caffeine, your first thought might have been coffee right? Caffeine is prevalent in everyday life and is loved by majority of athletes. There is substantial evidence to suggest a benefit for endurance-based activity. It has been shown to improve time to fatigue, time trial results, team sport simulations and strength endurance.
Creatine is a supplement with a large evidence-base for performance enhancement. Creatine can be found naturally in the diet (red meat, fish) in small amounts that are heat sensitive. There is substantial evidence to suggest that there is a performance benefit for explosive sports. The supplementation of creatine can increase intramuscular creatine stores in the body by more that 30%. It is also likely to increase the rate that energy is generated from Phosphocreatine resynthesis during short term, high intensity exercise.
Nitrate is found abundantly in leafy green and root vegetables such as beetroot. There is strong evidence to suggest that nitrate may be beneficial to various exercise performances such as endurance-based activity of around 40 minutes duration. Researchers found that the time to fatigue improved by 4-25% and improved time trial scores by 1-3%.
Beta-Alanine is a rate-limiting precursor of carnosine. Carnosine is an endogenous intracellular (muscle) buffer. It accounts for around 10% of the muscle’s ability to buffer hydrogen ions during high intensity exercise. Hydrogen ion accumulation is also known as Lactic Acid build up and contributes to that “burning” feeling you experience in your muscles when you’re close to fatigue.
Now that you have all you need to know about taking care of your health and body through nutrition you're ready to take on exercise with the knowledge on how you can properly fuel your body in the best way possible!
If you would like to see what other content we will be delivering in the coming weeks, make sure you keep an eye on our social media and newsletter for any updates!
Disclaimer: As a service to our members, UWA Sport has provided this material for your information only. It is not intended as a substitute for medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about nutrition, supplementation, exercise treatment or care with your health care provider.
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