by Bob Vandersluis

 Do you ever wonder what you should be eating in your off-season, pre-season, before a game or on all of the other days of the year?  You’re not the only one.  I’ve had multiple athletes in the last week ask me some really good questions about their daily nutrition, and specific habits that they can adopt to enhance their performance the day before, or the day of competition.  These questions are not uncommon, as many inexperienced athletes get a lot of information, bad information, from outdated and misleading sources.
YOU DON’T KNOW WHAT YOU DON’T KNOW
I remember when I was a teenager, training, practicing and playing all sorts of games, and my fuel a lot of days was a can of Chef Boyardee, a brownie and some fruit juice.  This was a typical lunch for me.  I was never given any great advice on how to properly prepare for the strenuous schedule of competition and training.  Well, not exactly true.  I was given a tip once that I should eat a carb filled meal a couple hours before games.  I put this into practice when I played Jr. hockey and was very religious in the timing and portion size.  It became a great habit that helped me fuel, short term.  Little did I know was that the one meal per week that I was regulating, was having very little effect overall.
In order to understand a bit more about the overall influence that nutrition can have on athletic performance, we are putting together a series called “Fueling for Performance: An Athlete’s Guide to Nutrition Practice”
PART 1: Understanding Training Nutrition
Nutrition goals are not static.  Like a good training program, nutrition protocols need to be periodized.  (1) Overall, an athlete’s nutrition strategy should focus on providing adequate substrate stores to meet the fuel demands of the event and to support cognitive function.  (1)
Energy availability, which equates the balance of energy intake and energy expenditure.  Care should be taken to preserve health and long term performance by avoiding practices that create unacceptably low energy availability and psychological stress. (1)  When you are engaged in any form of physical activity, your body needs some form of food.  If you don’t provide it, it’s like a car running on empty. (3)
3 Reasons Athletes Should Eat
1) Replenish energy stores
2) Increase muscle size and/or muscle quality
3) Repair any damage caused by the activity
Replenish Energy Stores
Our ability to run, bicycle, ski, swim, and row hinges on the capacity of the body to extract energy from ingested food. As potential fuel sources, the carbohydrate, fat, and protein in the foods that you eat follow different metabolic paths in the body, but they all ultimately yield water, carbon dioxide, and a chemical energy called adenosine triphosphate (ATP). Think of ATP molecules as high-energy compounds or batteries that store energy. Anytime you need energy—to breathe, to tie your shoes, or to cycle 100 miles (160 km)—your body uses ATP molecules. ATP, in fact, is the only molecule able to provide energy to muscle fibers to power muscle contractions. Creatine phosphate (CP), like ATP, is also stored in small amounts within cells. It’s another high-energy compound that can be rapidly mobilized to help fuel short, explosive efforts. To sustain physical activity, however, cells must constantly replenish both CP and ATP. (4)
Our daily food choices resupply the potential energy, or fuel, that the body requires to continue to function normally. This energy takes three forms: carbohydrate, fat, and protein. (See table 2.1, Estimated Energy Stores in Humans.) (4)
Increase Muscle Size and/or Muscle Quality

You need roughly 2,800 calories to build a pound of muscle, largely to support protein turnover, which can be elevated with training.

The contractile proteins and fluid (sarcoplasm) in muscle fibres are broken down and rebuilt  every 7 – 15 days. Training alters the turnover by affecting the type and amount of protein produced. Again, muscles respond to the demands placed on them.(5)

Although growth can take place during starvation/restriction, especially for newbies, muscle growth with inadequate calorie consumption is less likely to take place with advanced trainees, as their threshold for growth is elevated.

If you’re more experienced and looking to get big and strong, you’ll probably have to eat more.(5)

Tips for enhancing muscle protein synthesis

  • Just 6 grams of essential amino acids can stimulate muscle protein synthesis after training.
  • Elevated levels of insulin can generate muscle growth when amino acid consumption is ample, which demonstrates the importance of carbohydrate consumption after exercise.
  • Frequent amino acid consumption (from food or supplements) during the waking hours may also play a role in muscle growth.

Repair Damage Caused by Activity

In  order to produce a training adaptation, physiological system requires an overload stimulus greater than what it is currently accustomed.  It is recognized that muscle damage is essential to gain strength and size.

Despite the desire to break muscle in order to enhance athletic performance, the recovery after training is essential to be able to train frequently and optimally.  Replenishing glycogen stores through carbohydrate consumption, and repairing muscles tissue through protein and amino acid intake are keys to recovering adequately.

If an athlete is glycogen depleted after exercise, a carbohydrate intake of 1.5g/kg of bodyweight during the first 30mins, and again every 2-4h will be adequate to replace glycogen stores.  (5)

Protein consumed after exercise will provide amino acids for the building and repair of muscle tissue.  In order to maximize the amount of protein absorbed during digestion (if using a protein powder supplement), athletes can sip on protein and consume slowly, mix it in oatmeal or a shake, or use digestive enzymes.

Ideally, athletes should consume a mixed meal providing carbohydrates, protein, and fat soon after a strenuous competition or training session. (5)

References

1) http://www.dietitians.ca/Downloads/Public/noap-position-paper.aspx

3) https://www.umass.edu/sphhs/sites/default/files/NutritionandAthleticPerformance_TamTran.pdf
4) http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources
5) http://www.precisionnutrition.com/all-about-muscle-growth