I was encouraged by your recent piece on a women-only gym chain in Saudi Arabia (NuYu, HCM July 17, p70).

Even though that club operator is based in the Middle East, there’s also a clear need for female-only fitness facilities to be more widely available to women across the UK.

Recent studies suggest women are risking their health by exercising less than men, and self-consciousness, childcare and housework are all being blamed for this failure to exercise.

In addition, women with faith demands or personal beliefs that involve modesty and traditional dress can feel limited or uncomfortable when working out in a more conventional exercise setting, such as in a health and fitness club.

Research suggests that in-gym women-only areas are not just a cultural necessity for ensuring uninhibited workouts, but that the brains of men and women are wired differently and trigger different reactions to exercise.

This is why having a women-only gym in all 17 branches of Total Fitness across the north of England and Wales has proved to be so important.

We often see a selection of female members who use the non-intimidating environment of the women-only gym as a stepping stone to the main gym floor, while others choose to stay in there throughout their membership, due to the sense of community developed among the group of like-minded women. Some even tell me that our women-only gym is why they chose to join our facility instead of the other local health clubs.

After all, it’s not all about how women look when they exercise – how they feel is also really important.

Having a dedicated space to themselves helps to nurture this feeling of psychological and emotional wellbeing.

Lauretta Ihonor’s Editor’s Letter (July 2017) raised important points on the use of statistics in making the case for getting more people, more active, more often – specifically those related to the ‘cost of inactivity’.

However, I believe the notion that the sector is misrepresenting figures to gain traction and exaggerating impact is wide of the mark. At ukactive, we don’t tend to use ‘cost to the NHS figures’. The figure we use regularly – physical inactivity costs the UK £20bn each year – is taken from the government’s own figures in a Public Health England report.

When calculating the ‘impact’ of our work we generally have to turn to the best available tools at our disposal. Both the National Institute for Health and Care Excellence and Sport England provide means of predicting the financial saving provided to the NHS with simple information such as the number of participants involved and levels of activity. With these simple metrics, sophisticated modelling then predicts health outcomes based on how physical activity has been demonstrated to contribute to a whole host of conditions and how much each of those conditions costs to treat and/or manage.

There is one major assumption we make in this process, and that comes from relying on self-reported physical activity data as opposed to any knowledge related to the actual amount of movement completed by individuals. This makes it very hard to predict any health outcomes that might be achieved.

We can, however, take steps to solidify our assumptions and work towards an evidence base for the real-world health impacts of physical activity. The routine collection of health-related outcomes and monitoring of actual behaviours will increase the power of our predictions, and give stakeholders, policy makers and commentators alike greater confidence in our calculations.