Worst-case scenario. SHTF. You've got all your gear ready, made all your plans and are about to bugout. No other choice than on foot. You load up as much gear as you can carry and get the hell out. Off to a good start. 2km's later you're out of breath and in trouble. For all your preperations, you forgot one thing. You needed to be in shape.
As you struggle to recover your breath, the situation gets worse, there's only one of them, thankfully, but they've seen you and you'll never be able to out-pace them now. You go to drop your gear and turn to face the threat, but it's too late, you're already exhausted and your assailant moves in for an effortless attack. You've never been in, or learnt how to fight...
That's the great thing about prepping. It encompasses EVERYTHING in your life. From something as simple as carrying tissues, to something as serious as battling a natural disaster.
I find personal fitness is something that is overlooked, especially with all the "zombie apocalypse" hype. (It's a bit of fun, yes. To the oblivious - for fucks sake it's a metaphor.) Do you have the endurance and mental perseverance to get to safety or enough skill to defend your body and belongings?
Being fit and physically healthy does wonders for a persons mental health as well. The harder you work at it and more you achieve, the happier, healthier and more likely to succeed you will be in other aspects of life. I can personally attest to that. This leads to you being able to concentrate on what's going on around you, increasing your awareness, which is very important in high stress situations, especially when the adrenalin runs out.
Just like you do with bush craft skills, or first aid application, or just about EVERY skill you learn from prepping, you HAVE to practice. Everything is a perishable skill.
Am I capable of travelling long distances on foot carrying heavy gear? Yes. I work physical jobs, am very active and spend a lot of time in relevant outdoor activities.
Am I capable of physically defending myself? Yes. I've been training in martial arts and combat sports half my life, I've sparred and fought in and out of the gym.
Do I have the capacity for cognitive thinking to limit putting myself in harmful situations? Yes. Life experiences, relevant training and hands on experience.
There are many other activities you'll encounter that require specific fitness skillsets, but the fitter and stronger you are, the better chances you'll have at overcoming and adapting.
The most important part is putting into practice the things you learn, and pressure testing them, so you know what does and doesn't work. If you don't experience this you'll never have an inkling of what will happen when things get serious.
There is always going to be someone fitter, stronger and better trained to handle obstacles than you, but being mentally and physically prepared are important steps to take in terms of self defence and self preservation. Are you doing as much as practically possible to ensure yourself the best chance in any given situation?