Updated: Jun 27
We all know that exercising is a key aspect of maintaining a healthy lifestyle which protects us against diseases, as well as other benefits such as boosting our mood. Our sports nutritionist Francesca tells us why in her expert opinion sports nutrition is so important.
Whether you are a professional athlete or someone who simply enjoys working out, what and how much you eat or drink can have a huge impact on your personal goals.
In particular, diet plays a crucial role in the enhancement of sports performance, providing fuel to the muscles and body fluid replacement. Sufficient energy should come from a variety of foods that provide you with enough carbohydrates, protein, fat, and micronutrients, to prevent injuries and enhance your performance.
Depending on the level and form of physical activity performed, your energy and nutrient demand will change – when you move your body, the cells require more energy than the fuel they needed at rest. This, for example, means that athletes’ diet demands more than a balanced diet, as their energy intake must match their higher energy expenditure. Therefore, it is essential to adjust the food and fluids you intake to improve your performance, enhance recovery and avoid the depletion of energy reserves. Regarding this aspect, a nutritionist specialising in sports nutrition will play an essential role by using individualised dietary advice. Francesca can help advise you if you, please contact us to request a free 15-minute phone call.
Where does the energy come from?
Having a balanced diet can help your body to get the calories and nutrients needed to carry you through the day or while performing a workout. Our main source of energy comes from the food we eat – carbohydrates, protein, and fats. These macronutrients provide a different amount of calories (kcals) per gram:
1 g of fat provides 9 kcal, 1 gram of protein 4 kcal and 1 g of carbohydrates 4 kcal.
Let’s have a closer look at these macronutrients and see why they are so important.
Often demonised, this macronutrient plays a crucial role for everyone involved in any kind of physical activity. Carbohydrates are the main fuel used by our brain and muscles during exercise and, therefore, consuming an adequate amount is fundamental to prevent muscle fatigue.
From a scientific point of view, carbohydrates are broken down by our body into glucose and then stored in the muscles and liver as glycogen. These stores are an essential source of energy when we work out but are limited. Therefore, a key strategy is to start exercising with your glycogen stores completely topped up.
Your carbohydrate requirements solely depend on the type of physical activity performed, the intensity, and duration.
In general, a daily intake of 2-3g per kg of body weight is advised for those who follow a low-intensity skills-based programme (such as yoga, Pilates, pace walking, etc. or exercising less than 3 times/week),
3-5g per kg of body weight for those who follow a moderate program (that last for around 45-60 minutes),
6-10g per kg of body weight for endurance athletes (training for 1-3hr per day with moderate/high intensity) and 8-12g per kg of body weight for those taking part in an extreme event (such as Iron Man, etc.).
Examples of foods providing around 50g of carbohydrates:
2 medium bananas,
15 dried apricots,
2 thick slices of bread,
60 g of breakfast cereals
or 1 large potato.
Contrary to carbohydrates, while exercising, proteins are not usually used by our body as fuel but are critical in muscle repair, growth, and strength development. Insufficient protein intake will lead, over the long term, to muscle damage, injuries and illness. Regardless of our fitness target, we all need solid and fully developed muscles to succeed in our performance. Therefore, to sustain muscle growth it is vital to stay in a positive protein balance – this means that we need to have more protein available than the amount that will be used during physical activity.
How much protein should we consume?
Following the recommendation of the SACN, adults are advised to consume around 0.75-0.8g of protein per kg of body weight per day.
This amount is well enough if you regularly go to the gym (3-4 times per week) but, for athletes (endurance or strength, lifting moderate to high weights), it may be beneficial to increase their protein intake slightly to promote muscle tissue growth and repair.
Sedentary -to 1 gym session per week
If you are a sedentary person or someone who goes to a gym class once a week, your daily protein requirement will be around 0.8g per kg of body weight, and this amount can be easily achieved with your daily diet (we usually consume more protein than needed).
For endurance athletes or runners and cyclers, a good amount of protein per day will be 1.2 – 1.4g per kg of body weight, while if you do heavy training (with weights) or resistance sports you should consume 1.6 -2.0g of protein per kg of body weight.
When speaking of protein it is important to bust the myth that the more protein you eat the more muscle mass you will gain – if you eat more protein than required your body will use it as energy.
Distribute protein intake evenly throughout the day
Furthermore, the latest guidelines recommend to evenly distributing your protein intake throughout the day, rather than having it in one single meal, and to aim for 20 – 25g of protein per meal or snack (3 main meals + 2 snacks). The reason behind this recommendation is that our muscles prefer using a small amount of protein over one day.
Examples of foods providing around 20g of protein:
2 medium slices of beef or 1 small chicken breast,
200g of low-fat yoghurt,
3 medium eggs,
400g of baked beans,
240g of Tofu,
140g of quinoa or
6 ½ tablespoons of Quorn mince.
Fat is the third of our essential macronutrients, and it makes part of the structure of our cells membranes, bone marrow, brain tissue and it protects our organs. It is interesting to know that our body uses the fat stored in our muscles for low-intensity activities (i.e walking or yoga). But we should monitor our fat intake as large amounts could cause weight gain and health problems. In fact, compared to protein and carbs, fat is the most energy-dense nutrient.
Contrary to carbohydrates and protein there are no specific guidelines for fat intake. Athletes and active individuals should follow the healthy eating guidelines that recommend that fat should represent 35% of our total daily energy intake.
Food containing saturated fats, such as butter, biscuits, cheese, processed meats should be limited, and more unsaturated and omega-3 fats should be included in the diet. Unsaturated fats include avocado, olives, almonds, or pumpkin seeds and omega-3 fats are present in foods such as fatty fish (salmon, mackerel), nuts, and seeds (walnuts, flaxseed, chia seeds), and plant oil (canola oil, flaxseed oil, and soybean oil).
Hydration and fluids replacement
Finally, we must not forget the importance of being well hydrated. It is essential to highlight the importance of hydration as water is essential for life and our body is made up of around 70% of water. The result of severe dehydration could be an impaired sports performance, headache, nausea, dizziness, heat-related illness, reduced mental function and, in the worst case, death. Therefore, maintaining an adequate fluids intake is crucial for succeeding in your performance, both mentally and physically. You should always start your workout and competitions well hydrated and replace the fluids (and salt) lost through sweating as soon as possible.
The recommendations for the general population are to drink around 2 litres of water per day if you are a man and 1.6 litres if you are a woman. However, these recommendations do not take into consideration individuals’ sweat rate (the amount of fluid you lose through sweat) and exercise. Therefore, it is fundamental to tailor hydration strategies to your personal needs. Your goal should be to always be hydrated and not just to start drinking when you feel thirsty, as you might be already dehydrated.
One recommendation is to stay away from all those fancy sports drinks (which are usually expensive).
Tailor your fluid intake with isotonic drinks:
Low to moderate-intensity exercise
If you train with a low to moderate intensity (which means exercising for less than 1 hour) you only need water.
Moderate to high-intensity exercise
While, if you are into a moderate to a hard session (that last more than 1 hour) you should opt for Isotonic sports drinks that can be easily made at home with 200ml of squash, 800ml of water and a large pinch of salt.
In conclusion, there are 4 goals that you should keep in mind:
Refuelling your body with carbohydrates and fluids as soon as possible after exercise.
Drinking enough fluids to be well hydrated throughout the day and before, during and after physical activity.
Choosing a variety of food that also provide you with enough carbohydrates based on your needs.
Eating a varied and balanced diet (including fruits and vegetables) to fuel your body with energy that should come mainly from carbohydrates, followed by proteins and fats.
Francesca is our sports nutritionist who used her sports nutrition expertise while she was a ballet dancer for most of her life. Francesca uses this unique insight to provide clients practical, insightful and lifestyle-driven nutritional advice in both Italian and English. She is a registered associate nutritionist with the AfN. Please contact us to request Francesca's expertise.
References for further reading:
1. Potgieter S. Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. South African Journal of Clinical Nutrition 2013;26(1):6-16. Available from: https://www.ajol.info/index.php/sajcn/article/viewFile/88379/77991
2. Beck K, Thomson J, Swift R, von Hurst P. Role of nutrition in performance enhancement and post exercise recovery. Journal of Sports Medicine. 2015;6:259-267. doi: 10.2147/OAJSM.S33605. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4540168/
4. American College of Sports Medicine, Academy of Nutrition and Dietetics and Dietitians of Canada. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal of the Academy of Nutrition and Dietetics, 2016; 116: 501-528. https://jandonline.org/article/S2212-2672(15)01802-X/fulltext