Bell Curve Water Aerobics

Wednesday, May 10 2023

Travel back in time with Mark when cardio training was continuous and there was no rest or recovery. Rediscover aerobics, choreography and that thing called a bell curve. Retro Waves is a high-energy water aerobics class that showcases water specific movements that can be taught in both deep and shallow water


Fresh from debuting Retro Waves at the International Aquatic Fitness & Therapy Conference (IAFTC) in Orlando, the video has just posted on Fitmotivation and an online AEA online quiz worth 1.0 AEA CECs is also available. This entire dual-depth class is designed around 8 aquatic base moves, their variations and water specific adaptations. 
HIIT is popular, but if you always do what you always did you will always get what you always got. Offering both steady-state and intermittent intensity training can help your class members improve their overall fitness and be prepared for whatever energy demands life throws their way.

Intermittent Intensity Training
Intermittent intensity workouts feature interval training that includes cycles of high intensity exercise alternated with lower intensity movement or rest. HIIT workouts are an example of this style of training. The higher the intensity of the work bouts, the greater the need for rest. If adequate rest periods are not alternated with bursts of high intensity exercise, then it is not HIIT. This type of workout is considered anaerobic training because working at such a high intensity, the body cannot meet the demand for oxygen and thus performs in the absence of it, hence the breathless effort.

  • Research has suggested that more body fat is burned when high intensity exercise is alternated with bouts of rest/recovery. 
  • The same research also indicates that the metabolic rate stays elevated for a longer period of time following intermittent high intensity training. 
  • Short bouts of all-out exercise prepare the body for unexpected activities where a sudden burst of energy is needed, such as running through the airport to make a connection. 

Steady-State (Aerobic) Training
During a steady state workout, the heart rate stays within a set range, for example 60-80%, for an extended period of time, such as 30-minutes. Steady-state workouts are referred to as aerobic exercise. Working at a steady state of energy expenditure allows the body to provide oxygen during the extended cardio activity. This results in a more measured scale of effort, without the breathlessness associated with HIIT. 

  • Improves heart health
  • Associated with positive weight loss results and a better mood.
  • Less risk of injury with more moderate exercise
  • Prepares the body for longer duration activities, such as a day of shopping or sight-seeing.  

Both types of training improve physical fitness and help class participants meet the demands of daily living.  Aerobic capacity is required for stamina and the ability to perform long duration activities, such as house cleaning or long walks. Anaerobic function is needed to prepare for sudden bursts of activity, such as walking up a couple flights of steps when the elevator is broken or dashing from your car in a rain storm.   

Watch Mark talk about the inspiration for Retro Waves in the video below, and the read more about bell curve energy expenditure, water specific moves and dual depth programming.


Back in the days when hi/lo and step classes were popular, instructors were encouraged to design their aerobic classes with a bell curve of energy expenditure. They learned how to progress, peak and regress exercise intensity. For example, the energy expenditure for the first 10 minutes of class might be 60%, followed by 70% for the next 10 minutes and finally close to 80% in the middle of the class. This energy expenditure would then be reversed on the descent down the bell curve, going back down to 70% and then 60%.

Aquatic Exercise Selection on the Bell Curve

  • Combinations of movement tend to be less intense depending on the complexity. More complex patterns tend to reduce intensity as students navigate the kinesthetic awareness and coordination required with the choreography. This is a good choice for 60-70% expenditure. 
  • Deconstructing patterns and repetitions down to the single movement will tend to yield the highest output, such as 80%. In the workout. In the video, the peak of the bell is when we break the movement down to singles. 
  • Movements performed with multiple repetitions are less intense than single repetitions as there is less change involved. Adding repetitions is a good way to decrease intensity. Another way to regress is to perform movement slower, at the half-water tempo.

Showcasing Water-Specific Exercises
Water specific exercise refer to moves that can be done in the water but would be impossible or unsafe to do on land.  These moves typically have both feet coming off the floor at the same time.  The reasoning behind this is that when exercising in water you should take advantage of the unique aspects of the aquatic environment that allow for more suspended, acrobatic movement. It is a workout in the water and so instructors should it make it a WATER WORKOUT. The Retro Waves Workout includes several water specific moves. 

Retro Waves was designed specifically to be done in both deep & shallow water. In fact, many of the IAFTC sessions were designed this way. Why? 

  • Benefits of Dual Depth Instruction (Shallow and Deep Simultaneously)
  • When pool times and space are limited, offering a class that allows people to spread out in both deep and shallow can be a solution.
  • Independent contractors can increase their income potential
  • Offering a deep & shallow simultaneous format allows participants to choose the depth they prefer
  • Instructors do not need to offer modifications for individuals who try to participate in a deep-water class in the shallow end or vice versa

Get ready to ring the bell and make some Retro Waves in your classes. In fact, consider bringing a bell to your classes and ring it when they reach the peak or the pinnacle of power. With that said, I sure hope your students enjoy this workout as much as I enjoyed practicing it in the pool.


Author: Mark Grevelding is the founder of Fitmotivation. He is also a training specialist and consultant with the Aquatic Exercise Association’s (AEA). Mark has been active in the fitness industry for 22 years as a group fitness instructor, personal trainer, international presenter and a continuing education provider for AEA, AFAA & ACE.