I am not a lawyer, I have no legal experience or skills. These are my opinions, but I hope they may be of use to you. To help you avoid problems.
As a keen sports (wo)man your interest may be cycling, running, gymnastics, whatever. It may even be the martial arts, karate, aikido, or any of a wide range of systems.
My concern here is that you may be out training by yourself, without a partner. Thus at risk of being mugged or worse.
Possible? These days, probably Probable!
Consideration Number One you are most definitely not allowed to carry a weapon to protect yourself against the risk of attack, or anything which can be construed as a weapon. Legal Fact! The measure is: Reasonability. Is it reasonable for you to be carrying a baseball bat when out on your bike? Or that ninja sword when going to the public swimming baths? Would a jury consider it reasonable A carpenter with a screwdriver, Yes; but a road runner with the same No!
If you are carrying anything which could be construed as a weapon as you go to the gym or an event, youd better have a damn good reason for having it with you, particularly if you happen to use it to flatten a...