The Science of Resetting Your Bodyweight
The Science of Resetting Your Bodyweight
By Carla Sottovia, Director of Personal Training & Fitness Education at the Cooper Fitness Centre and Precor Master Coach
We can all agree that achieving and maintaining your ideal bodyweight is not just a matter of eating and/or eliminating certain foods from our diet. It is a matter of a complete lifestyle revamp that includes eating healthier nutritional foods, food portion control, physical activity, and adherence to good lifestyle habits (i.e, adequate sleep, moderate alcohol intake, no smoking, stress management, social support, and the list goes on). As stated by Dr. David L. Katz from Yale University, “Lifestyle is the Best Medicine’ (Nutrition & Behaviour Change Summit, IDEA WORLD Conference, July 2016).
Changing one’s eating behaviour takes some learning and planning. It is fair to say that what, when, and how we eat matters. Our body needs three main essential substrates for its daily function and survival: a) carbohydrates; b) fats, and c) protein. Each of those substrates have specific roles that are crucial to our survival. For instance, carbohydrates are essential to our brain function and the body cannot survive without it. CHOs are also crucial to energy production during physical activity. Fats are essential to the structure and flexibility of cell membrane as well as to transport essential nutrients between the membranes. They are also a key source of energy during aerobic exercise. In addition, proteins are involved in many cell structures and function including muscle cell, hair, nails, skin et.al. Proteins do not provide energy during exercise.
The key question arises: how much should we consume from each of these substrates? About 1/4 of your dinner plate should contain healthy carbohydrates (i.e. whole grains/ legumes), 1/2 should be vegetables and fruits, and 1/4 should be lean protein and fats, In general, we want to focus on a higher intake of plant-based versus animal-based protein and fat. Taking the time not only to prepare meals, but also to be mindful and present when eating, helps the body create new habits. Ask yourself: am I hungry? Is it time for my meal or am I eating out of boredom? Being mindful of why you are eating and aware of what you are eating will help you develop long lasting healthy habits. We want to eat and consume foods that have a purpose.
Physical activity is a must to enhance caloric expenditure, boost metabolism, and maintain optimal body weight. How much, how often and how intense your activity will depend on your current fitness level. For starters, assuming that you are exercising less than three times per week, building a solid cardiovascular base is a must. According to ACSM guidelines:
a) Frequency: 3x per week, gradually increasing to 5x per week
b) Duration: 20-30 minutes, gradually increasing to 45-60 minutes
c) Intensity: Moderate
d) Activity: walking, stationary cycling, elliptical trainer
Once you achieve consistency with your physical activity (i.e. a minimum four 45-minute workouts per week for 12 or more weeks), boosting your exercise intensity will help increase your fitness level, metabolism and caloric expenditure. The use of training heart zones is a good way to track your exercise intensity. Intensities varying from 70% to 90% of aerobic capacity can certainly elevate caloric expenditure during a single training session. The use of heart monitors is a great way to zone in on the right intensity as well as to provide quantifiable information, such as metrics on calories, intensity and recovery timing. Heart rate training zones can be easily estimated with the use of general equations (Appendix A).
Another option is to gauge your exertion through five different training zones. The numbers below indicate the percentage of maximum heart rate per zone:
Zone 1 (50-60%): low intensity, able to carry a conversation
Zone 2 (65%): moderate intensity, increase in sweat and perspiration, but still able to carry a conversation
Zone 3 (70-80%): moderate to high intensity, somewhat hard effort
Zone 4 (85-90%): high intensity
Zone 5 (90+%): all out effort
Zone 1 and 2 are safe to use with beginner exercisers. Zone 3 is recommended for steady state and aerobic conditioning goals, followed by Zone 4 and 5 for greater metabolic stress. Training zones can be used interchangeably during a training session depending on the individual’s fitness level, goal and rest and recovery level.
Over time your new eating and exercise habits will become part of your lifestyle; the key is to have consistency with your new eating and exercise routine. Physiological changes, such as an increase in aerobic capacity, and physical changes, such as a decrease in fat mass or body weight, will gradually take place and eventually become long lasting. And just remember your ABCs: Action, Behaviour and Consistency.
- MIndful eating: why, when, and how we eat matters.
- Plan your meals: breakfast/lunch/dinner/afternoon snack
- Favour whole grains over processed foods
- Plant-based proteins are an essential protein source
- Eat fruits & vegetables
- Perform physical activity at least 4x per week
- Vary your workout training intensity by incorporating heart rate zone training
- Integrate a variety of physical activities
- Prioritise rest and recovery
- It is all about creating new lifestyle habits!
Appendix A: Heart Rate Reserve Method (ACSM)
Predicted maximal heart rate (MHR) reserve = 207 - (0.7 x age) x (%Intensity)
Example for a 45 year old exerciser:
- Predicted Max HR: 207 – (0.7 x 45) = 175
- To identify HR reserve for each training zone, calculate the lower and upper ends of each range, such as:
- Zone 3 Low: 207 – (0.7 x 45) x (70%) = 123 +/- 5-8 beats per minute
- Zone 3 High: 207 – (0.7 x 45) x (80%) = 140 +/- 5-8 beats per minute
Edwards, S. The Heart Rate Monitor Guidebook to Heart Rate Training. Sacramento, CA, 2008.
Halvorson, R. Sprints best for fat loss. IDEAFit.com, May 2012.
Sachs, L. Ex RX: Exercise results can be improved with a proper use of a Heart Rate monitor. IDEAFIT.com, May 2011.
Sottovia, C. Energy Substrate: Truths & Misconceptions. Dallas,TX. ISBN:0-9785952-0-3. 2006.