Crunch operates premium health clubs, each with around 4,000 members, and our average club revenue for nutritional supplements is US$6,000 a month. The lowest revenue per club is around US$4,500, with the highest around US$16,000.

So we’ve had a lot of success with nutritional supplements, but I wouldn’t ask members to buy a product I didn’t believe in. We have a long-standing partnership with Dotfit and much of our success is down to the quality of its product and the support it provides through training – it puts a lot of resources at my disposal for training staff. In addition, there’s not one challenge I’ve been presented with that I haven’t been able to find the answer to on the Dotfit website.

In addition to this, we only hire staff who are aligned with our views on exercise science. At the outset, we ask them for their thoughts on nutrition and about their own experience with multi-vitamins. Members’ goals generally involve losing size, but side-effects of dieting include a nutrient deficit and the loss of lean muscle tone. In order to accomplish weight loss while still maintaining good tissue and retaining nutrients, they need multi-vitamins.

Trainers need to be comfortable conversing with clients about nutrition too. This is a sensitive subject, as it encompasses ethnicities and how people were raised.

You run into obstacles and negative perceptions, but we start the conversation with members from the very beginning. We give them a nutrient starter kit with a 30-day supply of vitamins, some meal replacements and snacks. Trainers then pick up on the subject at orientation and take it from there.

I’ve built supplements up to account for 30–40 per cent of income at my pro-gym, without borrowing a penny. In fact, it’s worked so well for me that I’ve entered into a partnership to open a high street shop and an online shop, because I’ve practically run out of space in the club.

We stock four ranges – whey protein, branch chain aminos, mass gainers and fat burners – across a number of brands: MET Rx, USM, Dorian Yates, NRG, Fuel, Boditronics, Optimum Nutrition and BSN. It’s important to stock the products your members will recognise: look in the magazines your members read and see which brands are promoted, then invest in them. Offer a mix of premium and budget products that are well marketed by the manufacturer. Start off small – you don’t have to invest thousands of pounds.

Revenue streams like this are key to survival for those of us who are going up against the budget chains.

It’s very important to supply the body with the right nutrients after exercise, and Mitonics is revolutionary in that exactly the right protein requirement is calculated for each member, based on their weight and body fat percentage. We work hard to educate members about the importance of nutrition, and have found this precise and scientific approach resonates with them.

After their first workout, we encourage members to try a shake. Once a month, we run a promotional day with free tastings that we promote via email and Facebook.

We’ve just designed some new programmes – Weight Off, Muscle Up, and Lean and Tone – which have special drinks to complement the programmes. These have proved hugely successful.

Although other revenue streams are more significant, protein drinks are a very important part of the offering at our two clubs, and will be at the six new clubs we’re going to be opening this year.