The question of which is best for your spine is often a divisive issue among trainers.

Many recommend the ‘classic’ version that is designed to work best for the individual.

But others are more keen on the ‘functional’ model that offers some added flexibility to the spine and can help you to ‘fit in’ more comfortably in the gym.

The two most popular options are the PowerTap 3.0 and PowerTap 4.0.

Both are excellent products, but the difference in the quality of the equipment is often less than the difference of price.

Here’s our guide to the two best options for you to consider.