Fitness logos are usually required to represent several ventures like sports facilities, nutrition companies, fitness clinics, gyms, personal trainers, etc. The logo you choose would have a direct impact on how potential customers view you or even notice your brand.
When the logo represents fitness, this is the main message you want to convey. Within this, you can use several symbols in order to help viewers understand what kind of business you run within this field. For instance, you could use a dumbbell and weights as part of a logo for a gym. Some green leaves could signify healthy eating and be associated with nutrition centers.
Along with the symbols, you can make use of colors to evoke a connection to the fitness world. A logo for healthy food shop, for instance, might want to have the color green as dominant in their logo. This signifies health and therefore fitness. If you’re searching for a logo to represent a men's-only gym, a deep blue color could be masculine enough. The same goes for a company providing supplements mainly for males. Pink would be best for a women's’-only yoga, spin, or Zumba class.
In short, your branding style, design and color combination would all come together to emphasize your message to your audience. To clarify your message, you may want to add a tagline to your logo. The font of your brand name and the tagline should be neat and straightforward, since high-impact activity is the usual aim for anything to do with fitness. You may hence want to go for the Serif or Sans Serif fonts.
Hiring a professional logo designer would ease most of your worries about the perfect fitness logo. At least consult a logo design expert in this field in order to be sure about your choices of symbols, colors, and overall design.