We have all heard the term burning calories and how you need to burn calories to drop weight and body fat. Yes all of that is true, but by only using the most effective methods.
CrossFit is a high intensity training program that utilises weights in its workouts. Participants are required to complete a workout, that may consist of heavy weights combined with up to a few more exercises, as quick as possible (safely) and this creates a physiological reaction that is optimal for calorie consumption. Once you have completed your workout, and if met the workout criteria, your body will then continue to burn calories after you have completed your workout.
This physiological effect is called excess post-exercise oxygen consumption, or EPOC. Also known as oxygen debt, EPOC is the amount of oxygen required to restore your body to its normal, resting level of metabolic function (called homeostasis).
Our foods are often measured in calories or kilojoules. You would have seen these on labels and on food packaging. 1 calorie is the amount of energy needed to heat 1 litre of water 1 centigrade. The body consumes 5 calories to consume 1 liter of oxygen.
So what workouts will raise this EPOC?
EPOC is influenced by intensity, not duration. 10 minutes of hard and heavy movements, will be far more beneficial than doing 40mins of long slow continuous. One study found that when aerobic cycling for 40mins at 80% Max HR, circuit training (4 sets/8 exercises/15 reps at 50%1RM) and heavy resistance (3sets/8exercises at 80-90%1RM to exhaustion) were compared, heavy resistance exercise produced the biggest EPOC.
- Heavy lifts that do not last more than 10 seconds. If the weight of the lift is heavy enough, you may only be able to perform 1-3 reps and with a certain degree of struggle. Constant engagement of muscles in this 10 seconds is key. You will utilise 100% of your ATP-Creatine stores. ATP is your energy units (little sparks in your engine).
- Workouts that produce “the burn”. The infamous burn is when you continuously move your muscles to rep from 15-20 reps non stop. These types of exercise blocks will work the muscle long enough to get into the second energy system called the Lactate Energy system where lactate if produced from the workout, including hydrogen ions which give the burn. This raises your EPOC and the need for more calories to allow you to recover.
That is why you sometimes you continue to sweat for an hour later even after you have had a shower! That is your body burning energy to help you recover from your workout.
There also needs to be a caloric deficit in your food consumption as well. You can never out train a bad diet. Here are some nutritional tips to steer you along the right path:
Eat meat and vegetables, nuts and seeds, some fruit, little starch and no sugar. Keep intake to levels that will support exercise but not body fat.
- Reduce carbohydrate consumption. You may be eating far more than you need to.
- Increase good fat consumption. You may not be eating enough, so your body is storing it.
- Time your food intake after your workouts. No shakes or food for 1 hour after if trying to shed fat.
- Reduce your stress and anxiety levels. Take more breaks in the day, stretch and relax. Highly stressed individuals cannot mobilize fats well.
So there you have it. The reason behind how crossFit burns calories and helps you to shed fat. The method and the science behind it. It assists but is not a guarantee. It is possible to CrossFit or perform exercises at high intensity and still not get any change out of your efforts if your food intake does not change. You need to decide what you want the most and take decisive action to change. Change is not easy but the journey is worth it.
Sign up for your first CrossFit class here and get started in your fitness journey here. Join the many hundreds of satisfied exercisers who have lost fat with CrossFit.