If you’re a runner you’ve probably heard ALL about glucose and glycogen. But if you’re new to running, let’s start with this:
Along with fat, glucose is the body’s preferred sources of fuel in the form of carbohydrates. Carbohydrates are found in bread, rice, pasta, potato, fruit, vegetables and dairy products, just to name a few.
When our body digests carbohydrates it is broken down into glucose to use as energy. Glycogen is a form of carbohydrate that the body stores in our muscles and liver. During exercise, especially high-intensity exercise, muscles tap into this glycogen storage to produce ATP, the energy currency muscles need to contract.
If you do not have enough glucose or glycogen available, your body does use fat stores to give you energy, but as exercise intensity increases, you can’t mobilize fat quickly enough to meet your body’s energy demands resulting in:
- Decreased performance
- Feeling shaky lightheaded or dizzy
- Being nervous or anxious
- Sweating, chills and clamminess
- Irritability or impatience
- Fast heartbeat
A great analogy I like to use is the fuel in a car scenario. Without fuel, you’re not going anywhere, and if you’ve ever experienced trying to drive anywhere on very VERY low fuel your car starts to drive slower and slower and until it stops completely.
That’s what happens with low/no glycogen stores in athletes. You may be able to get to the finish line or push out a mediocre training session, but you definitely won’t be performing at your best!
On average our bodies store enough glycogen for 60-120 minutes of exercise. Although this is completely dependent on the person, what they have eaten in the lead up to training, and how hard they are training.
As a general rule of thumb:
1-4g/kg of carbohydrates 1-4 hours before exercise
Example: if you weigh 60kg = 60-240g. This is quite a wide range as it depends on how intense your upcoming session is and how long you have to eat and digest the food before commencing.
45-75 minutes: Small amounts, possibly just a carbohydrate mouth rinse
1-2.5 hours (including start/stop sports): 30-60g of carbohydrates per hour
>2.5-3 hours: up to 90g of carbohydrates per hour using multiple types of carbohydrates (e.g. glucose and fructose)
If you are training less than 8 hours after your previous session:
Consuming 1-1.2g/kg of carbohydrates 30 minutes post-exercise followed by every hour for 4 hours until normal meals resume will replenish your glycogen stores, enhance your recovery and ensure you are well fueled for your next session.
Consuming ~20-25g of protein post-exercise will also enhance the rate that your body replenishes its glycogen stores and aid in rebuilding your muscle.
To further aid in building muscle efficiently, ensure your protein serves are spread out evenly throughout the day.
Overall daily carbohydrate intake is also important for your recovery and ensuring you’re fuelled for your next session. This is often overlooked in recreational athletes and something that is actually hard to do! You will most likely have to make a conscious effort to seek out high carbohydrate foods and force yourself to up your intake of those foods and usually reduce protein and fats. If you’re currently under-eating with your carbs, you will definitely notice a HUGE difference to your training performance when you get them up to optimal, and then you’ll love life! More carbs plus better performance, what a winning combination!
Daily carbohydrate fuelling guidelines:
- Sedentary or low-intensity/skills-based training = 3-5g/kg/day
- Up to 60 mins of moderate-high intensity training = 5-7g/kg/day
- Moderate endurance training (60-180 mins) or moderate-high intensity training = 6-10g/kg/day
- Heavy endurance training (>4-5 hrs) of moderate to high-intensity training = 7-12g/kg/day (ultra-endurance event training)
Again, these numbers provide quite a wide range due to differences in individual requirements, training types and intensities.
For more information around sports nutrition and in particular endurance running, you can speak to Nutritionist Clare, who has experience running 100km Ultra Marathons and adapting her nutrition accordingly.
Or alternatively please do not hesitate to contact Thrive on (03) 9318 3455 or come visit us in-store.