I am honoured to be training the Seagods Dragon Boat team once again. It’s not long to go until this year’s race events, so it is useful to remind ourselves about the role of food and nutrition in our energy systems. I also delve into the optimal strategies for race day events.
Food = Energy
Food supplies energy to the body. The quality of the energy is determined by the quality of the food.
To the degree that the food on the plate is close to its natural state determines how much energy you will derive from it. Organic grass fed meat returns more energy per mouthful than salami does.
In terms of energy output, we have three distinct yet interrelated energy systems. Each has a different fuel mix.
The short term energy system lasts from 1 to about 10 seconds and is best epitomised by a 100 metre sprinter. After that short period of time, the ATP-pc breakdown is exhausted and energy output- or performance- decreases. The fuel adenosine triphosphate and creatine phosphate is stored and utilised in the muscles to contract and relax and produces great speed and power.
The second system kicks in around the 15 second mark and is predominant up to around 2 or 3 minutes. This is the lactic or anaerobic system. A national level 800 metre runner is a good example. The fuel for this system is blood glucose.
The third system takes over at the 3 minute mark. The aerobic energy system uses oxygen to turn muscle glycogen into glucose and fuel. The trained body can store up to two hours of glycogen before depletion. At lower intensities and longer duration, fat stores contribute more and more to energy output.
If there is little or no fuel, then replacement fuel comes from breaking down muscle tissue. This is a very inefficient way of getting energy and results in the unattractive gauntness you see in endurance athletes and anorexics. This is the creation of new glucose- glyconeogenis- and is to be avoided if possible.
What is the “Correct” Fuel Source?
In order to determine which fuel source is “correct” for our purposes, we have to know the intensity and duration of our event.
A race start takes perhaps 10 seconds, so we definitely use this short term energy system, however, care must be taken not to exhaust it. A 250 metre race takes 1.10 (more or less) and a 500m race 2.20 (more or less). This means the aneroid lactic system is the main energy system.
It is pertinent that a high intensity race of longer duration can only be reached and maintained over the day on the backbone of endurance training. The wider the base, the sharper the peak.
What is Energy?
In it simplest form, glycogen and glucose is sugar, or in other words, carbohydrate.
This is where is gets complicated because of blood sugar levels and the desire of insulin to keep it balanced. Any excess glucose is first stored in the muscle as glycogen, then converted to fat.
Use of Carbohydrate Gels
The timing of carbohydrate gels, with or without caffeine, is critical to able to use this flood of sugar into energy and hence race speed. The timing is that you must ingest it, assimilate it and use it- before insulin takes it.
If the sugar rush is very high then you will have a crash on the other side that will negatively affect your intentions and have fatigue, and is felt when you have a urge for something sweet (carbohydrate). This depends on gastric emptying, what’s in the stomach, and also adrenaline from arousal state, intensity of exercise.
Generally a gel within a 5-10 minute window before you want to use it is optimal. Anything after and you risk crashing; anything before and the stomach will shut down to move blood and energy or adrenaline to race muscles.
Adrenaline is the “fight or flight” hormone that you need to arouse your senses. However, there is a finite amount of time you can do this before you become exhausted.
Ergogenic aids such as caffeine create the same stimulation response as adrenaline. Likewise, overusing this strategy can cause the same yo-yo of high/crash as abusing sugar. Practice is advised for individuals to get the timing right.
Short term events such as a 250 or 500 metre event will absolutely benefit from this strategy!
Combined with normal healthy and balanced eating of a mixture of fats, proteins and carbohydrates, there will be more than enough blood glucose for an hour to ninety minutes session.
Race Day Challenges
The puzzle to solve is how to ensure we are supplying optimal fuel when there are 3 – 4 races spread over a 10 hour day, as time to digest a normal meal needs to be factored in.
Consider the following-
1. Humans need to eat every 4 hours. When people starve, a stress/adrenal response kicks in.
2. Time to digest dependent on the balance of fats, proteins and carbohydrate takes around 90 minutes. Carbohydrates by themselves take less but have the mentioned insulin response. High intensity activity on a full stomach usually results in sluggish movement or vomiting.
3. Individuals vary on the fuel mix and performance.
4. In general vegetables, nuts, seeds and small amounts of fruit are health carbohydrate sources. All processed carbohydrates such as muffins, bread, rice and pasta have greater insulin responses especially in the absence of fat or protein.
5. If it takes 2 hours to digest my breakfast and my race is at 7am, that means I need to eat an easy-to-digest meal at 5am and then a reasonable meal again at 11am to refuel, and have 2 hours to my next race. This is unlikely.
I suggest having a normal dinner the night before with perhaps slightly more vegetables or carbohydrates.
An easily-digested breakfast such as a coconut milk smoothie with perhaps some ground nuts and a banana, or scrambled eggs on toast with butter should be taken as early as possible.
Post-race, refuel as soon as possible with a balanced meal.
Endurance racers have a 15 minute window in which to ingest a high carbohydrate solution to quickly replace muscle glycogen as if the ratio of carbohydrate to protein was 3:1.
Hydration, as always, is essential to manage. The more you sweat, the more dehydrated you get. A drop in 2% hydration can affect performance by up to 10%.
For events less than 1 hour, water is fine. For longer events, a 4-10% carbohydrate and or electrolyte solution is fine.
Current thinking is that urine should be a straw colour. Clear urine signals that the electrolytes from the body are draining. You will know you are electrolyte-depleted if you get cramps, but by that time it’s too late. Sip little and often.