Freelance work!

I have been offered a job with a gym in Edinburgh, they are keen to update their logo and are wanting some t shirt/hoody designs created as well.
This their current logo:

The brief they have given is quite open but with certain ideas in mind;

• Involving the words Athlete Training Systems.
• Something fun people would want to wear, bought for the design.
• Geek culture, games, fitness and sport.
• Clients are very sport but also very into comics and games - tie the two together.

I have gathered some images to start of my research, including current gym apparel, games related apparel designs and gym logos.