It ain’t what you do, it’s the way that you do it

Only by fully appreciating the physical properties of water can we work it in a way that elicits maximal benefit.

How many times have you heard a client say ‘she just doesn’t work us as hard as so and so’, and how often have you duplicated movements from a workshop only to find that your clients aren’t feeling the intensity in the workout?

Whilst how we deliver a class, coach and motivate our clients, harness the power of music, prepare our sessions and use equipment affect aquatic class outcomes, it is essential to fully understand the physical properties of the water and to appreciate that it’s the way we work the water that makes all the difference.

So let’s take a look at some of the physical laws as they apply to the aquatic environment and affect the intensity of a water fitness session.


Put simply, inertia is change – and it affects aquatic movement in three main ways.

Total body inertia. This can alter intensity if travelling is incorporated in the choreography. When travelling it takes more energy to start, stop or change direction of the entire body against the water.

Water’s inertia. This can be experienced when travelling, especially when changing direction after a distance, as you are trying to reverse the water’s motion as well as your own. Travelling in a circle and then changing direction will allow you to experience the inertia of the water.

Limb inertia. Every time you move a limb through the water, it takes effort to overcome inertia. This happens when we move the arms and legs.


This is where more force or muscular effort is added to a movement. It does not necessarily mean that the speed of the movement is increased, as the additional force can be applied to enlarge the movement, spring higher or lift the knees more forcefully between movements, while maintaining the original cadence.

Motivate participants to accelerate by using cues such as ‘push harder’, ‘take bigger steps’, ‘jump higher’, ‘lift your knees’ or just ‘use the water’.


The viscosity of water enables aqua fitness participants to feel the reaction more readily than on land.

The upper and lower body can work with each other (assisting) or against each other (impeding). When the arms and legs work against each other, more resistance is created and more force is required, e.g. jogging forward with ‘reverse breaststroke’ arms. When the arms assist the legs, however, the work load reduces, e.g. jogging forward with ‘breast stroke’ arms.

Frontal resistance

Frontal resistance refers to the part of the body presented to the water in the intended direction of travel, and the bigger the area the more force required to move it. Movements sideways tend to be less intense than those which move forwards and backwards. Hand positions also affect surface area, so it’s important to teach people how to position their hands to work the water to increase the effectiveness of the workout.


Our arms and legs are our levers, and the longer the lever, the harder the muscle works to move through the water’s resistance. Remember that the hand and foot position affect lever length. Always start a session with short levers and always maintain soft joints when lengthening out through the limbs.


There is a perennial debate among aquatic fitness professionals about speed of movement in the water, and many people have their own ideas about this, all of which are valid.

Yes, increasing speed does increase water resistance which does increase intensity, but as aquatic fitness professionals, we need to watch that the range of motion and quality of the movement is not compromised, and to provide feedback to participants if it is. It should also be noted that some individuals are unable to maintain movement at speeds high enough to alter or influence intensity.

For many of my sessions, rather than talk about ‘fast’ and ‘slow’, I talk about ‘hard’ and ‘easy’ sets to describe the force being used against the water.

Only by fully understanding the physical properties of water can we elicit the true benefits of aquatic exercise, through offering alternatives and variations to our programming.

Claire Barker-Hemings is an Aquatic Exercise Association (AEA) international trainer who delivers training and workshops to fitness professionals. In her 20-year dance and fitness career Claire has taught everything in fitness, from dance to circuits.