1- Genetics
2- Hormones
3- Diet
4- Sleep
5- Exercise
6- Activities of daily living
Obviously there is not much you can do about genetics, that boat sailed long ago, blame your parents. The rest of these items are on the table. As I am sure you are aware, all of these factors are interrelated, some more than others. I'd like to focus on diet, exercise and activities of daily living because they are the major factors in energy conversion. A goal of weight loss is to use more energy than you take in.
Balancing bodily energy is a
lot more complicated than calories in (food we eat) and calories out (exercise and activities of daily living). Calories eaten and subsequently used during voluntary movements are only two small parts of the energy equation and insignificant by themselves. Your total energy expenditure fluctuates daily and is quite difficult to accurately measure. Most of your calories are spent on metabolic processes:
- calories are burned during all involuntary movements (breathing, heart beat etc.)
- heating the body due to environmental temperatures
- calories are used in bone and soft-tissue growth
- the largest caloric drain on the body comes from brain functions
- metabolism of food
- calories used on a everyday basis to combat infections
- tissue restoration
There is no one best form of aerobic exercise or machine that burns the most calories. According to Kravitz and Robergs, "based on the fundamental principles of indirect calorimetry, to burn more calories during exercise you need to increase oxygen consumption. The issue of exercise and caloric expenditure is as simple as that." Research shows the greatest impact on caloric expenditure during exercise comes from contraction of skeletal muscles which therefore increases oxygen uptake. The more oxygen you need during exercise the more calories you burn. Listed below are the other factors during exercise that play a role in calorie burn:
- the amount of muscle fibers being used
- complexity of the movement
- prior experience with the exercise
- weight bearing exercise vs. non-weight bearing
- balance and proprioception requirements
- resistance and incline of machine
- your total body weight (the heavier you are the more calories you burn)
- the amount of lean muscle mass you have
- speed and intensity level
- duration of the exercise
- temperature of the room (colder rooms will induce higher energy demands)
Please keep in mind that any one of the machines listed below are capable of inducing a higher caloric expenditure than the other. This list is an estimation of which cardio machines have the potential of burning the most amount of calories when all other factors are equal:
- Cross Country Skiing
- Running on the treadmill
- Rowing
- Step-Mill (the one with real steps)
- Elliptical with Arms
- Jump Rope
- Biking upright
- Recumbent biking
- Arm ergonometer
1. McARDLE, W.D. et al. (2000) Energy expenditure at rest and during physical activity. In: McARDLE, W.D. et al., 2nd ed. Essentials of Exercise Physiology, USA: Lippincott Williams and Wilkins.
2. DAVIS, B. et al. (2000) Physical Education and the Study of Sport. UK: Harcourt Publishers Ltd.
3. MayoClinic.com; Exercise for Weight Loss; 2009
4. Borg G.A.V. Psycholphysical bases of perceived exertion. Med. Sci. Sports Exerc. 14:377-381, 1982.
5. Toner, M.M., Glickman, E.L., & McArdle, W.D. Cardiovascular adjustments to exercise distributed between the upper and lower body. Med. Sci. Sports. Exerc. 22:773-778, 1990.
