Updated: May 29, 2022
Some days we just crave to eat “some crap” and sometimes the smell of pork fat hitting charcoal or a griddle is just too much to handle…
Depending on YOUR unique activity level - exercise and its demand - your energy amount and specific energy nutrients will differ.
From the food we digest, our bodies break down the nutrients into circulating and stored energies: our bodies tap into these at varying exercise intensities and duration.
Protein is predominantly used to rebuild structures.
- We aim to have this at a minimum of 2g per kilo of bodyweight or around 25-30% of daily calories.
Carbohydrate becomes glycogen in muscles and blood sugar in circulation.
- For most exercising people, aiming for 40-55% of your daily calories can help restore carbohydrates. In general, athletes will need to consume 3 to 5g per kilogram body weight daily for light activity and upward of 8 to 12g per kilogram body weight per day for intense training.
Fat is in the blood, liver and stored tissues.
- For most people, aiming for a total fat intake of 20-30% of you daily calories. I do not recommend consuming less than 15% to 20% of total calories from fat because it is essential for many processes.
We transfer these energies to make ATP.
ATP is energy that is stored in our muscles for fast reacting high output but short lived energy. This is a compound that enables short bursts (1-10s) of energy. Like a 100-meter sprint or a 1-5 rep lift.
After it is used, the body will move on to either anaerobic metabolism (using insulin and stored carbs) or aerobic (using fatty acids, carbs and oxygen) to continue to create ATP and fuel your exercise.
Olympic lifting or strength - 1 rep every 3 minutes - 8s per rep - explosive tension - High use of ATP-CP and carbohydrate (glycogen) - Lower calorie expenditure but high use of carbs and protein
Bodybuilding - 6-12 reps and 75s rest - approx 8 - 30s per set - prolonged tension - Uses ATP and carbohydrate (glycogen) ‘the burn’ - High use of protein and carbohydrate, moderate calorie expenditure.
Conditioning and cardio - Rep circuits, continuous resistance, distance runs, grunt work - constant tension and prolonged effort work - Uses ATP, oxygen, protein, fatty acids and available carbohydrates. - Slower because it relies on oxygen being transported to the muscle to produce ATP. - High calorie expenditure from fat, carbs and protein.
During a session, you move through these pathways.
The Order of Events
As exercise begins, ATP is used, then carbohydrates take on the work and produce lactic acid as a byproduct.
With breathing and heart rate increasing making oxygen available, the aerobic systems take over until the anaerobic (ATP AND CARBOHYDRATE) systems kick in again. Typically this is what makes you stop to rest and breathe OUT.
Remember - we have to recreate ATP and rebuild this whole cycle continuously.
Having an understanding of how macronutrients contribute to the fuel supply show us how it gets converted to ATP.
Carbohydrate is the main nutrient that fuels moderate and high intensity exercise.
Fat fuels low-intensity, long duration exercise.
Protein repairs body tissues and is not normally used for muscle activity.
It's important to consume fat, carbohydrates, and protein in your diet.
Depending on intensity and duration of activity, will depend on the energy substrate you use most.
So is it carbs, or fats?
This all depends on your training, your unique biochemistry and also your own preference...
Carbohydrates are the main macronutrient that fuels moderate and high intensity work, fat provides energy during exercise that occurs at a lower intensity.
Fat is great for endurance but just not adequate for high-intensity exercises such as Olympic lifts, sprints or intervals.
If exercising at low intensity like walks, you have enough stored fat to fuel activity.
Carbohydrates are more efficient than fats but have limited storage (muscles, liver and blood sugar) and therefore it is important during longer sessions (especially around 40 minutes) to take on board some carbohydrate and help omit the ‘wall’.
As you grow more muscle and train, you get better at using and storing carbohydrates.
It’s also important to not negate training cardio and get the nutrients muscle cells need for:
- Muscle contractions (calcium)
- Muscle relaxation (magnesium)
- Support transport of blood sugar into cells (insulin, sodium and potassium)
- Clearing toxic byproducts (antioxidants, vitamin C, E, zinc/hydration/breathing)
You can continue moderate to high-intensity exercise for longer by simply replenishing carbohydrate stores during exercise.
Taking on board bananas, carb powders, coconut waters, cranberry juices and other carbohydrate sources that are easy to digest can help fuel activity, especially after the first 20 minutes.
Example macro splits - not a given, just examples.
Rest Days and Walks P 33% C 33% F 33%
- no huge increase or need unless long hikes, good balances of all macros help satiation and vitamin and mineral intake for most activities.
- eat when hungry, not stuffed at most most meals.
- typically eucaloric (no reduction or increase in diet - i.e, maintenance)
Strength work P 25-30% C 45-50% F 20-25%
- Place calories moderately above your maintenance, this can be 2-400 calories above your maintenance depending on intensity and duration of exercise (typically 60 minutes).
Bodybuilding P 25-30% C 55-60% F 15-20%
- A calorie surplus for muscle tissue, place calories 4-600 calories above your maintenance depending on intensity and duration of exercise (typically 60 minutes).
Cardio work P 25-30% C 40-50% F 25-30%
- A calorie surplus for energy replenishment and recovery as well as clearing lactic acid. Focus on increasing all calories for the duration of exercise, anywhere from 6-800 calories depending on exercise intensity but importantly emphasising foods rich in antioxidants, magnesium, calcium, hydrating and breathing.
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