
As a member of Life Time Fitness, you are bound to hear certain assessment “buzzwords” used during your favorite classes or when talking with a fitness professional. Many of you may have heard the following terms before, but now it is time to look a little deeper into their definitions and why it is important to know what your “numbers” are.
Aerobic Base (aka “AB” or “Base”)
Before discussing Aerobic Base, it is beneficial to first define “aerobic”. Aerobic means “with oxygen”. When you are working aerobically, your body uses both fat and carbohydrates for energy.
Aerobic Base may be defined as the point where your body is most efficient at using fat as a fuel source during exercise. More specifically, your Base is set at the heart rate where your body is burning at least 50% of its calories from fat for energy. The first step in any good exercise program is to build a solid fitness foundation or “base-building”. A solid base ensures you are burning fat efficiently over a wider range of heart rates.
Unless you have an exercise metabolic rate (CardioPoint) assessment, base-building may prove difficult because there is no way to estimate one’s Aerobic Base. The CardioPoint assessment is discussed in further detail below.
Anaerobic Threshold (aka “AT” or “Threshold”)
Before discussing Anaerobic Threshold, it is beneficial to define “anaerobic”. Anaerobic means “without oxygen”. When you are working anaerobically, your body burns only carbohydrates for energy.
Anaerobic Threshold may be defined as the point where your body stops working aerobically (burning both fat and carbohydrates) and begin working anaerobically (burning only carbohydrates). Without a solid fitness foundation (a good Base), always working out at or above your Threshold may be counter productive because you may not readily lose weight or body fat. Threshold is different for each person and often varies from activity to activity (run vs. bike vs. swim).
Threshold can be estimated (which is explained as the “bronze” and “silver” methods for determining AT) and specifically measured (which is described as the “gold” method for determining AT).
Bronze:
o Complete the following equation: 180 – age = estimated AT. The answer will serve as your estimated AT in heart beats per minute (bpm). This is the least accurate of the three methods outlined for determining AT.
Silver:
o This assessment can be performed on either a bike, treadmill, or elliptical. Whichever modality you choose, begin at a comfortable work load to warm-up for approximately 2-minutes. After 2-minutes progressively increase your exercise intensity (treadmill grade or levels on bike and elliptical) every minute. Continue these 1-minute increases until you reach a workload where your breathing becomes labored to the point where you can only speak a few words at a time between breaths and when your muscles start to significantly burn. Note your heart rate at this point and this will serve as your estimated AT. This should not take any longer than 15-minutes to accomplish. If it you don’t get to these exertion levels under 15-minutes the intensity changes each minute were not substantial enough.
Gold:
o This method for specifically measuring AT includes an 8 to 12-minute exercise assessment where intensity is progressively increased while measuring oxygen and carbon dioxide ventilation with a sophisticated analyzer. A heart rate monitor is worn during this assessment so the metabolic technician is able to record the specific heart rate you are at when you reach your AT. This specific heart rate, along with your AB heart rate, will guide your cardiovascular training over the next few months. As with resistance training, it is important to progress the intensity of your cardiovascular workouts to avoid the dreaded training plateau. Therefore, it is important to re-assess your AT and AB every three to six months in order to ensure you are exercising at the correct intensity levels.
VO2max
VO2max is defined as the maximum capacity of oxygen someone can breathe, deliver to their cells, and utilize during exercise. The more oxygen utilized during exercise, the more work we are able to do (like walking faster and/or walking at a higher incline). Several factors such as high cardiac output (a strong heart), efficient muscles, and good genes determine how high a VO2max can get. VO2max is considered the gold standard for determining your exercise potential as a high VO2max indicates a high level of cardiovascular fitness.
A true VO2max measurement involves progressively increasing intensity over a certain period of time in an effort to fully tax the cardiovascular system. Using a sophisticated analyzer, oxygen and carbon dioxide ventilation are both measured and recorded until oxygen consumption no longer increases despite an increase in workload (speed and/or incline). The CardioPoint assessment at Life Time Fitness is considered a sub-maximal test and provides a VO2peak measurement, which is a little different than VO2max. VO2peak is recorded as the highest amount of oxygen one is able to take in and utilize during the assessment. Since the assessment is never continued to the point of exhaustion and concludes when one hits their Anaerobic Threshold, the assessment is rarely considered a true VO2max measurement. Keep in mind that a VO2max assessment should not be conducted without appropriate monitoring from a medical professional.
Recovery Heart Rate
Recovery Heart Rate is defined as the heart’s ability to return to a normal rate after you terminate a bout of exercise. An ideal recovery heart rate is between 20-30 beats within the first minutes. The more efficient and healthy your heart is, the quicker you will return to your pre-exercising heart rate. If you find that you are recovering slower than the recommended rate, it may be a sign that you need to increase the amount of cardiovascular exercise you are participating in during the week.
Recovery Heart Rate can be measured with a Heart Rate Monitor or by holding onto the heart rate sensors found on many of the different cardiovascular machines. You simply need to note your heart rate when you begin your cool-down, 1-minute later, and 2-minutes later. Then, calculate the differences and you will be able to compare your recovery heart rates to the recommended rates discussed above.
Knowing more about these buzz words will help understand what your numbers mean and how to use them to make better progress towards your current health and fitness goals.
In health,
Nathan Cermak
Master of Science (M.S.) Sport Studies
Metabolic Specialist
Heart Rate Monitor Team Lead
Certified Personal Trainer
Life Time Fitness – Chanhassen
2901 Corporate Place
Chanhassen, MN 55317