Nutritional Strategies

Evaluate the appropriateness of nutritional strategies that aim to improve sport and exercise participant’s performance.

Oxford English Dictionary (2003) defines a strategy as: 'a plan of action designed to achieve a long-term or overall aim'. So a nutritional strategy is a plan of action of what type of foods to eat, the quantities to eat them in and how long to do this for.

A very popular nutritional strategy used by many endurance athletes is called 'Carb loading' or 'Carbohydrate loading'. Class Notes (2015) describes Carb loading as: 'eating a higher than usual carbohydrate intake for 1-4 days prior to an event while tapering training'.

Jacques Delorme (2012). The video above describes the basics of carb loading and explains how athletes are using it as strategy for their particular sport.

Here is a diagram to show the theory of Carbohydrate loading. As you can see when we get to around 5 or 4 days before an event exercise/training decreases dramatically and the amount of carbohydrates eaten should increase heavily. 

The theory behind this is explained by Class Notes (2015) as follows: 'Muscle glycogen levels are normally in the range of 100-120 mmol/kg ww (wet weight).  Carbohydrate loading enables muscle glycogen levels to be increased to around 150-200 mmol/kg ww.  This extra supply of carbohydrate has been demonstrated to improve endurance exercise by allowing athletes to exercise at their optimal pace for a longer time.  It is estimated that carbohydrate loading can improve performance over a set distance by 2-3%.'

Therefore, the point of carbohydrate loading is to boost muscle glycogen levels to be able to perform over a longer period of time at a higher intensity. The sports performers who could benefit from carb loading are performers who are competing at a moderate or high intensity for over 90 minutes. For example, marathon runners, cyclists and endurance swimmers. 

Kara Corey (2014). The video above shows a marathon runner 'carb loading' before an upcoming marathon. The important part of the video is where the marathon runner says she has reduced her training hours and on the day before the marathon she is doing no training at all. The most common mistake by athletes is that they increase the amount of carbs but don't reduce training. Not resting will not give the full benefit of boosting the muscle glycogen stores as the majority of carbs will be used for training rather than being saved for the event.

A less scientific strategy is 'Food Preparation', this where an athlete or sport performer prepares several meals for each day which will contain sufficient nutrients required for them. The video below shows the daily food intake for a rugby player. It shows the importance of not just eating Protein and Carbohydrates and to always include fruit and vegetables in your diet. The video explains how preparing meals can improve your diet and sport performance.

James Haskell (2014). By not preparing foods you may miss out on nutrients you need or over intake on some. 

Another strategy to follow is called the Harris Benedict equation. 'The Harris Benedict Equation is a formula that uses your BMR and then applies an activity factor to determine your total daily energy expenditure (calories).' (Class Notes 2015). The video below describes the formula used and how to apply it to different sports performers. 

(Class Notes 2015) The diagram above shows in detail the formula used for males and females and how to work out your BMR (Basal Metabolic Rate) and PAL (Physical Activity Levels). 

The Harris-Benedict equation is a good starting strategy to use to find out a fairly accurate BMR. This will help to review if a sports performer has had enough calories or too many. However, the equation doesn't take into account lean body mass, therefore people with high lean body mass may under estimate calorific needs and obese people may over estimate calorific needs. It is also hard for a sports performer to define their activity level into lightly active, moderately active, very active and extremely active; it is too vague description without any numbers to back up each category.

Another nutritional strategy is to use Sports drinks rather than water to hydrate yourself before, during and after exercise. 

Hypertonic Sports Drinks

Hypertonic drinks contain over 8%t of carbohydrate and have a slower rate of absorption. Although they provide a source of carbohydrate replenishment, they are not ideal for optimal rehydration and may need to be consumed with other fluids. These are best used in the recovery stage after exercise.

Isotonic Sports Drinks

Isotonic drinks contain the same concentration of glucose to water as is found in your blood: 4–8% or up to 8g per 100 ml of water. They usually contain sodium, which makes them quicker to be absorbed into the bloodstream. An isotonic drink is useful whenever exercise has been prolonged or during warmer weather when sweat loss is higher. They can also be used effectively before exercise.

Hypotonic Sports Drinks

Hypotonic drinks have a lower concentration of carbohydrates and are more diluted than isotonic or hypertonic sports drinks. They contain less than 4% carbohydrate (4g per 100 ml of water) and are generally easily absorbed and well tolerated. Although water is adequate for non-endurance training or when sweat losses are small, these drinks may encourage fluid replacement through enhanced taste.

Class Notes (2015)

The above reference shows what sports drink provide on top of what water can. Water is considered sufficient for low intensity and short duration exercise however for high intensity and endurance sports a sports drink can improve sport performance as they provide carbohydrates (for energy), glucose and hydration.

It is important to always consider that your nutritional requirements are different from everybody else. Therefore, always seek professional advice from a nutritionist or doctor before implementing any strategies first.

References:

Oxford English Dictionary (2003) Strategy [Online] Available from: http://www.oxforddictionaries.com/definition/english/strategy [Accessed 2015]

Kara Corey (2014) Day of Eating | Pre-Marathon Carb Load [Online Video] Available from: https://www.youtube.com/watch?v=sG4LIJJisS0 [Accessed 2015]

Class Notes (2015) Nutrition for Sport Performance [Online] Available from http://vle.chesterfield.ac.uk/course/view.php?id=3196 [Accessed 2015]

Jacques Delorme (2012) Sports Nutrition - Carb Loading [Online Video] Available from: https://www.youtube.com/watch?v=5_1QXEbFjvk [Accessed 2015]

James Haskell (2014) The Daily Food Consumption of a Rugby Player [Online Video] Available from: https://www.youtube.com/watch?v=geYW-WWBIjI [Accessed 2015]

Claire Adam (2015) Harris Benedict Equation [Online Video] Available from: https://www.youtube.com/watch?t=60&v=0M6xfC2kDNY [Accessed 2015]

Class Notes (2015) Limitations of The Harris-Benedict Equation [Online] Available from: http://vle.chesterfield.ac.uk/course/view.php?id=3196 [Accessed 2015]

Class Notes (2015) Hydration Through Sports Drinks [Online] Available from: http://vle.chesterfield.ac.uk/course/view.php?id=3196 [Accessed 2015]