There are over 130 million people in the US alone that are overweight. Associated with heart disease, cancer, diabetes, arthritis, gout, asthma, depression and so much more, obesity is the second leading cause of preventable death. Although genetics and hormonal factors can play a role, for most the solution is simply a matter of shifting their ‘energy balance’.

As the law of physics states, “energy cannot be created or destroyed; energy must be either used or stored”. Therefore, energy balance is simply a matter of managing the energy you use or store. It is commonly referred to as balancing ‘energy in and energy out’. Given that energy is measured in kilocalories (thermal representation which food provides or burns) or kilojoules (mechanical representation of the amount of work we do), it makes sense to stick with the simple science of measuring kilocalories (energy in) and kilojoules (energy out). Since you can’t change what you can’t measure, the easy solution to weight loss is to simply measure how much energy you need and quantify the “energy in and energy out”. Without the accurate measurement, it is complicated to achieve an energy balance. Realize that each person is an individual and their body burns energy differently. Simply put, two people of the same age, gender, weight and lifestyle…do NOT burn energy the same. Therefore an accurate measurement is critical.

To accurately determine “energy in”, simply count the calories provided by the food you consume. Although this article will not go into nutrition, it is obvious that those calories in need to be based on smart choices of non-processed foods and the right ratios of proteins, carbohydrates and fats.

To accurately determine your calories out, you need to determine your resting metabolism (RMR) and physical activity (work). An RMR measurement, performed by an expert in gas analysis assessment, will determine the energy the individual needs to function (pump blood, organ function, breathe, maintain body temperature, think, etc). Although there are many formulas to estimate RMR, there are many factors that affect an individual’s metabolism. Therefore, to ensure accuracy it is critical that an exact assessment is determined.

To accurately determine your physical activity, measure the amount of work you do. Since energy spent for physical activity depends upon the type of work, the intensity, the energy systems used, and the duration of time, the PowerTap is the perfect tool, as it provides a direct measurement of the work, represented as a Kj. Since 1 Kj is equivalent to approximately 1 Kcal, the PowerTap’s computer provides immediate feedback, counting up the energy you are burning to pedal the bike.

Getting back to basic science, you need to create a deficit in the energy balance of 3,500 calories to lose one pound. This equates to 500 calories per day, in one week. By using exercise (work) to create the deficit, you will preserve muscle and/or increase muscle tissue and increase your resting metabolic rate, while strengthening the cardiovascular and pulmonary systems. As stated by the USDA, “To move toward a healthier weight and prevent weight gain, aim for about 60 minutes of moderate to vigorous intensity physical activity on most days. If you have lost weight, you may need 60 to 90 minutes a day to maintain your weight loss”. Therefore the key to weight loss and management is measuring your calories in and balancing that with your measured RMR. Then measure your energy out (exercise) to create the deficit in the energy equation and develop the cardio-respiratory & muscular systems.

Food labels provide the caloric measurement in food, making it very easy to keep track of the accurate measurement. It is now very simple to accurately keep track of energy out, by using the CycleOps Power Training System. The PowerTap is an innovative approach for quantifying key health behaviors (and their consequences when you lose fitness) and for evaluating starting points and progression in health monitoring. The PowerTap will accurately measure intensity and the demands of the exercise on the energy systems. By following a progressive training schedule based on organizing and measuring your exercise, you will effectively achieve health, wellness and fitness goals. Below is a very simple approach to a periodization plan based on Kj’s, that can easily be utilized in a weight loss plan. Based on the 1:1 Ratio (1KJ = 1Kcal), simply perform 3500 Kj’s over a period of 7 days, to lose one pound in a week. If you are new to exercise or short on time, a more realistic goal may be lose one-half pound per week by performing 1750 Kj’s. One can simply break down the Kj’s over a 7 day period of time, based on their schedule.

How much time will an individual need to ride, to meet their KJ goals? You can easily determine this by using Allen Lim’s calculator at: cycleops.com/CalorieCalculator.aspx.
As an example, an individual weighing 250 lbs, who averages 150 watts, would need to do the following:
30 minutes: 270 KJ
60 minutes: 540 KJ
90 minutes: 810 KJ

Below is a sample of simplified 8 Week plan, based on a safe and effective way to achieve weight loss, by merely measuring energy out as KJ’s. This example demonstrates an appropriate progression of gradually adding training volume (increasing KJ’s) over the 8 week period of time. This means that the client will begin by losing one-half pound per week and gradually work their way to one pound per week, by the end of the eight week period. By gradually increasing the training volume by 10% weekly, the client will safely absorb increased workload and their body will achieve positive adaptations, free of overtraining. The individual simply puts in their riding time, until they have achieved the goal KJ’s. This example is based solely on “energy out”, using the PowerTap, and assumes that the individual is balancing their energy in with their measured RMR and incorporating a smart nutrition plan. After performing the 8 week plan, the client will begin to lose weight and rev up their metabolism. They will continue the progression until they are more comfortable with exercise. They are then ready to take the next step, which is training specific energy systems. This means they are now ready to take the PowerTest to determine their Power Zones. They will then learn to perform workouts that will break down their goal KJ’s into periods of various intensity and time, to develop further weight loss while incorporating fitness goals.

Angie Sturtevant
Specialists in Sports Performance, LLC
Saris Cycling Group Fitness Education Director
CycleOps Power Master Training Specialist
USAC Elite Level 1 Cycling & Power Based Coach; USAT Triathlon Coach
ACE & AFAA Trainer and Continuing Education Provider
Metabolic Testing Specialist