Not only do George and Sammy go to the same gym but they like to coincide their visits to turn them into a social occasion. They prefer to go to the gym in their tracksuits rather than their casual clothes. If they have a strenuous workout, then after their shower they will have to change back into their sweaty gym attire. It could be that today will only be a light workout. However, both George and Sammy are carrying bags, which suggests that they have other clothes and towels in there. This means that they are planning to shower after and then maybe go for a pint to discuss their workout.
Sammy thinks that they should refuse to pay for their gym membership. These days, a refusal of payment would result in an expulsion from the club. Membership cards would be taken away and they wouldn't even be able to get through the doors let alone into the weights room. However, here electronic membership cards have yet to be introduced and George and Sammy would just march through to the changing room, not paying the £2 that is needed. Alternatively, Sammy is suggesting they find a different gym, but that might be further away and require a car ride to get there.
The gym they go to may well be the world's first Fitness First. The company turned the business into a worldwide commodity by putting up their rates every other month thus increasing their revenue. They kept their members by charging attractive women a lesser rate whereas the male members had to pay the increase in rates. The male members were always more than willing to pay the higher fees. It is not known whether they still do this today.