Exercise and physical activity is the crux of wellness. It is widely known the cardiovascular and immune benefits of exercise but it also aids in maintaining lean body mass, our stamina for other activities and maintaining metabolism as we age. Knowing information such as resting metabolic rate and maximum oxygen capacity can also be helpful in tailoring personalized programs for individuals to help optimize vitality.
Resting metabolic rate measures the amount of calories an individual would burn if they were at rest for 24 hours. Metabolism is the process of utilizing food to create heat or energy. Metabolic rate is the rate which the body converts food to energy. Indirect calorimetry is a technique which looks at the amount of oxygen consumed rather than the heat produced to look at the metabolic rate. This number can be very helpful to measure and used to guide individuals who are trying to lose weight. Often times we see patients incorrectly taking too little calories to sustain their daily activity needs and which results in inadvertently holding onto calories. It can also be used to measure the respiratory exchange ratio (RER) when done for 20 minutes. This looks at the ratio of CO2 produced to O2 consumed. It can be indicative to the type of nutrient (Fats or carbohydrates) which are being metabolized. This information can be helpful to maximize energy utilization during workouts but also with weight management. In clinical practice, it is also useful to identify those patients who truly are slow metabolizers when compared to others who have the same height and weight. This can lead us to look more intensely at thyroid and other hormone imbalances.
VO2 max testing is used to measure exercise capacity and can be used as a monitor for fitness. It is calculated by the amount of oxygen consumption/minute during an exercise protocol. Oxygen consumption can rise linearly with exercise up until a point. Gradually, the oxygen consumption plateaus as the intensity increases and the CO2 in the blood rises as the lactic acid in the muscle rises during exercise. This number when the oxygen consumption has reached a maximum is called the VO2 max. It is directly related to the general health of the cardiovascular system. Other factors which can affect VO2 max are age, gender, genetics, level and type of physical training. The VO2 max can be used as a gauge of general cardiovascular health but also to monitor progression of fitness with various types of training. It can be useful to identify the calories burned during different levels of workouts by linking it to heart rate. Working with trainers skilled in exercise physiology, the information can be used to guide nutrition and training protocols to achieve a client’s goals, whether it is improving endurance, changing body composition, or improving speed and performance.
The information is an objective measure of fitness just as blood pressure and cholesterol numbers are helpful for to identify cardiovascular risk. There are limitations to this test; the client needs to exercise for at least 6 minutes on exercise protocol to get the heart rate up. In most offices, it can be done on o bike, treadmill, or step. The VO2 test is versatile, quick, and reliable and can be done as a baseline assessment or several times during the year to monitor progress during a training season.