How is steady state aerobic exercise best defined Nasm?

Which of the following is a more effective strategy for traveling from one place to another in the shortest period of time: (1) adding miles to your trip by driving the back streets of a city to avoid traffic jams; or (2) taking the shortest, most direct route even if it means sitting on a freeway so congested that you only move a few miles an hour?  And which approach burns more gas and places more wear and tear on your car: the frequent starting and stopping of city driving or highway driving at a constant rate of speed? 

This scenario provides a rough analogy of how the human body responds to different types of cardiorespiratory exercise. High-intensity interval training (HIIT), which, in this scenario, could be considered similar to city driving, can be extremely effective for burning calories and improving aerobic capacity but at the expense of placing high levels of physical stress on the body. Conversely, steady-state training (SST) focuses on maintaining a consistent, low-to-moderate intensity work-rate for an extended period of time, which is comparable to driving on a highway. Like HIIT, SST can be effective for aerobic conditioning and burning calories, but it can require an extensive amount of time to do the volume of work necessary to achieve the desired results. 

So, is one form of training better than the other? Like almost all fitness-related questions, the answer depends on a variety of factors. In the car analogy described above, both options can help you get to your destination. Which one you choose depends on your personal preference—would you prefer to sit in slow-moving traffic or being in constant motion? 

The following table lists the features, advantages, and disadvantages of HIIT vs. steady state cardio. There is a large body of research validating each mode as an effective form of exercise; however, it is up to you to determine which one is best suited to help your clients reach their fitness goals in the shortest period of time.

Steady-state Training

Features

• Maintain a consistent speed, level of intensity and work rate during an exercise session. 
• Training intensity can be measured by maintaining a consistent work rate at a specific percentage of maximum heart rate (MHR), heart rate reserve (HRR) or aerobic capacity (VO2 max). Another option is to use ratings of perceived exertion (RPE), which allows you to use a 1-10 scale to judge the level of difficulty (1 being easier and 10 the hardest).

Advantages

• Exercising below the ventilatory threshold for an extended period of time puts less physical stress on the cardiorespiratory system and can be an effective way to prepare for an endurance event. 
• It is an established and proven method for improving cardiorespiratory fitness and enhancing aerobic capacity. 
• Increases mitochondrial density in type I (slow-twitch) muscle fibers, which can improve aerobic metabolism. 
• Increases cardiac efficiency; specifically, elevating stroke volume and cardiac output at a lower heart rate. 
• Enhances ability to use fat as an efficient fuel source, which reserves muscle glycogen to be used for higher-intensity exercise. 
• Steady-state training to improve aerobic efficiency generates less metabolic waste and cellular damage than HIIT workouts.

Disadvantages

• If the goal is weight loss, steady-state training may require extended periods of training time to achieve the desired level of caloric expenditure. 
• Using steady-state training to improve aerobic capacity may require lengthy exercise sessions, which can be a challenge for a busy lifestyle. 
• Extended periods of exercise can increase the risk of repetitive stress injuries. 
• Certain individuals may find it difficult to maintain the focus necessary to train at a constant work rate for an extended period of time.

Interval Training

Features

• Alternate between periods of high-intensity exercise and lower-intensity, active or passive recovery. 
• Both the higher-intensity work intervals and lower-intensity recovery periods can be measured as a percentage of MHR, HRR, VO2max or an individual’s RPE.

Advantages

• HIIT can be effective for improving aerobic capacity and/or calorie burning in less time when compared to high-volume, steady-state training. 
• The higher-intensity work intervals of HIIT can be based on an individual’s RPE, allowing that individual to start exercising at a relatively low intensity (as measured objectively) and progress from that initial starting point. 
• Interval training may be an effective strategy for individuals who become easily distracted or bored during longer exercise sessions. 
• Can improve efficiency of type II muscle fibers to produce energy via anaerobic glycolysis, resulting in greater metabolic efficiency. 
• Exercising above the lactate threshold can help stimulate production of muscle-building, fat-burning hormones such as testosterone, growth hormone and insulin-like growth factor. 
• Increases the effect of EPOC (excess post-exercise oxygen consumption), helping to burn calories after the exercise session is completed.

Disadvantages

• High-intensity exercise increases mechanical damage on muscle tissue, which could increase soreness and the perception of exercise as “painful” in deconditioned individuals.  
• Anaerobic metabolism results in an accumulation of metabolic stress that limits a muscle’s ability to function. 
• The high mechanical stresses of HIIT can increase the risk of a muscle strain. 
• The higher exercise intensities required to improve aerobic conditioning with HIIT may be uncomfortable or painful for some people. 
• An extended period of HIIT could deplete glycogen stores and result in gluconeogenesis, which is the metabolic process of converting protein to produce glycogen. This limits the amount of protein available to repair muscle tissue damaged by exercise.

5 Reasons Why HIIT Might Be the Best Choice (for You or Your Clients)

1. You have a busy schedule, which limits your training time; HIIT workouts can be done in 30 minutes or less, making them extremely effective for producing results in a limited amount of time.
2. You have been following the same cardio workout routine for a long time and have become stuck at a plateau, adding HIIT workouts could jumpstart your program so you continue experiencing results.
3. You want to train for a mud run or obstacle course race. These events feature physical challenges requiring anaerobic strength. HIIT can help you prepare to meet the demands of overcoming an obstacle, while also improving aerobic efficiency so you have the energy to finish the race.
4. You are exercising for weight loss. HIIT can help you burn more calories in a shorter period of time, while also providing an EPOC effect to help you continue expending energy even after the workout is over.
5. Because you like it. The best exercise in the world is the one you enjoy and will do on a regular basis. If HIIT works for you, go for it and have fun, but make sure you allow time for appropriate recovery because that’s where the real results happen.

5 Reasons Why Steady-state Training Might Be the Best Choice (for You or Your Clients)

1. You experience a period of high stress or find yourself wallowing in a grumpy mood. Steady-state workouts require lower levels of physiological stress, which could help you to clear your mind and change your mood.
2. You want to enter a race like a 10K, half marathon or marathon. According to the principle of specificity, the best way to train for an activity is to do the activity. If you want to complete an endurance race, you will need to plan on making time for long-distance, steady-state training.
3. You are visiting a city you have never been to before or have recently moved. A long, steady-state run, bike ride or walk can be a great way to get out and explore an area you have recently moved to or are visiting for the first time.
4. You are exercising for the health benefits. Regular, low-to-moderate intensity steady-state exercise can provide a number of health benefits, including helping to reduce the risk of developing a chronic condition like type 2 diabetes, high blood pressure or high cholesterol.
5. Because you like it. Some people simply enjoy going out for long runs or training for long-distance endurance events. There is no reason to change your workout habits as long as they provide you with the benefits you are looking for.

Regardless of whether you choose SST or HIIT, to keep seeing results it’s important to change workouts on a regular basis to keep from becoming complacent, which could result in getting stuck on a plateau and not achieving any results from the exercise program. The best workout program is the one that is done on a regular basis.

Are you seeking a new cardio routine? Guidelines from various leading health and fitness organization tell us we need to participate in cardio activities five times a week for a total of 150 minutes if we plan to exercise at moderate intensities; or three times a week for a total of 75 minutes if we plan to exercise at vigorous intensities; or some combination of both (1). But how do we define and distinguish moderate from vigorous intensity?

Unfortunately, this is where these same guidelines become murky as they provide a variety of complicated and inconsistent methods to distinguish the two.

Common Errors in Prescribing Cardio Programs

Many of us are familiar with the guideline that recommends an intensity that reflects a percentage of your maximal heart rate (HRmax) – calculated mathematically by subtracting your age from 220 (i.e., 220-Age). For example a 35-year old person would have an estimated HRmax of 185 beats per minute (220-35 = 185). If this person wants to train at 70% intensity she should keep her heart rate at 130 beats per minute (185 × 70% = 130).

However, this formula was never intended to be used as an instrument for designing cardiorespiratory fitness programs because maximal heart rate varies significantly among individuals of the same age. Estimating maximal heart rate from mathematical formulas can produce results that are ±10 to 12 beats per minute off the actual maximal heart rate (2). Ironically, although this guideline still exists on most pieces of cardio equipment, and is still referenced in many publications, the latest exercise guidelines now tell us to no longer use this formula given its inaccuracies as an intensity guide (1).

We are also told that the duration of each cardio bout should be at least 10-minutes in length to be beneficial. Does that mean that a 5-minute bout of exercise is essentially worthless? The answer is absolutely no as new research now demonstrates that even as little as four minutes of exercise may offer some positive benefits, especially for those individuals just beginning an activity program (3).

Furthermore, we are also told that our aerobic program should follow the FITT-VP principle that represents frequency, intensity, type, time, volume, pattern and progression; with each principle involving various and sometimes complicated scientific guidelines (1). Confused? Understandably so, but what if we simplified the entire process so that you could develop your own personalized cardio program that is based on science, but easy to use and follow?

1. Start by first identifying cardio activities you currently participate in that you find enjoyable and feel confident in accomplishing. These are the activities you should participate in to get started.
2. Next, following a simplified version of FITT-VP mentioned previously (what we will call VIP), let’s develop your program:
3. Determine your realistic availability and commitment to your cardio program – identify the frequency and duration (i.e., volume) you are willing to commit to for exercise for the next four weeks. This should be based upon your current volume, but also consider your availability and confidence in completing this selected volume.
4. Use the scale presented below to select an intensity you feel confident you can sustain for the duration of your cardio sessions (4). Keep in mind you will be able to choose between exercising at a steady-state intensity (fixed pace), performing intervals (e.g., a few minutes pushing a little harder followed by a lighter recovery, repeated several times), or following a combination of both.

• V: Volume or the amount of cardio you desire to complete on a weekly basis. For example, if you decide to participate in three cardio sessions this week, with each being 20 minutes long, then your weekly volume equals 60 minutes (3 x 20 minutes).
• I: Intensity or how hard you plan to push yourself. We will use the exertion scale provided below, basing your breathing and ability to talk to score as your intensity. This marker of intensity is preferred over a percentage of some mathematical calculation as breathing reflects your own unique metabolism and fuel utilization.
• P: Progression or how you plan to advance your program over time so that you continue to make improvements to your overall fitness and health. This generally ranges between 5% and 20% per week. See this blog for tips on progressions and regressions.

• Week 1: Calculate your initial volume (e.g., 3 sessions with each lasting 15 minutes equals 45 total minutes for the week).

• If you opt to follow an interval format, use an average intensity (e.g., a 3-minute work interval at “6” coupled with a 3-minute recovery interval at “4” averages to a score of “5”; a 5-minute work interval at “6” coupled with a 2-minute recovery interval at “3” averages/round to a score of “5”) (1).

1. Develop your VIP program as follows: Volume x Intensity = Weekly Goal Challenge.
2. Plan your progressions: Weekly progression must be earned, not just awarded. In other words, by achieving your weekly goal challenge, you grant yourself permission to progress your VIP program. As an example, a 10% weekly progression will increase your weekly goal challenge as follows:
3. Your goal is to achieve your weekly challenge, which is recognized by permission to progress forward. Although your objective is to attain your weekly VIP challenge points as planned, it is important understand that points can be achieved through various modifications that allow flexibility to accommodate any unexpected or necessary changes to your schedule. Using week one as an example:

• For example, 3 sessions a week, each for 15-minutes at an average intensity of “5” equals 3 x 15 x 5 = 225 total weekly points.

• Week 1: 225 points.
• Week 2: 247.5 points (round to 250 points for simplicity).
• Week 3: 275 points.
• Week 4: 302.5 points (round to 305 points for simplicity).
• If you do not attain your weekly goal challenge, repeat the same weekly goal challenge the following week.

• Modifying Duration: 2 sessions x 20-minutes at a “5” + 1 session x 5-minutes at a “5” equals 225 points.
• Modifying Frequency: 2 sessions x 22½-minutes at a “5” equals 225 points.
• Modifying Intensity: 3 sessions x 12½ -minutes at a “6” equals 225 points.

The advantages of the VIP program lie in its simplicity, flexibility, ownership or accountability assumed with developing your program and controlling your progression, and its personalization – in that it is built around what you can do or desire to do rather than what you feel you need to do. Now that you are armed with this new tool, NASM challenges you to build your own program, and kick start your plan for a healthier new you.

References:

1. American College of Sports Medicine (2014). ACSM’s Guidelines for Exercise Testing and Prescription (9th Edition). Baltimore, MD: Lippincott, Williams and Wilkins.
2. Visich PS. Graded Exercise Testing. In: Ehrman JK, Gordon PM, Visich PS, Keteyan SJ, eds. Clinical Exercise Physiology. Champaign, IL: Human Kinetics; 2003:79–101.
3. Tabata, I., Nishimura, K., Kouzaki, M., Hirai, Y., Ogita, F., Miyachi, M., & Yamamoto, K. (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Medicine & Science in Sports & Exercise, 28(10): 1327–1330.
4. Kenney, LW, Wilmore, JH and Costill, DL. (2012). Physiology of Sport and Exercise (5th Edition). Champaign, IL: Human Kinetics.