https://palife.co.uk/news/workplace-wellbeing/brits-waste-503-million-on-unused-gym-memberships-in-2025/
Also people who join gyms in other months are more likely to use the gym more.
Also from my experience of Slimming World and Weight Watchers, huge numbers sign up in January then I probably saw about 3 people after mid Feb.
People give up to easily. Time and patience are key to lose weight, gain muscle etc. Some people think 6 weeks will shift 2 stone. Only people who are 20st plus probably lose this.
Half a billion £s wasted in gym memberships