Let’s begin with this revealing video from Matt Thornton of Straight Blast Gym in the US –
First off, I agree with the thrust of what he’s trying to demonstrate. For any serious student of martial arts, the concept of “aliveness” should be an integral part of one’s training program. You could probably train all your life and not really be getting to the meat-and-potatoes of the art/style/system that you're doing. It would be just be a series of empty physical movements devoid of its intended function; that of preparing you to defend yourself if and when that time comes. Otherwise, you might as well do something else like badminton or swimming.
That being said however, it’s HOW you introduce it in your training program that makes the difference. As I've mentioned before, HOW something is taught and learned can be far more relevant than WHAT is being taught. I've heard of horror stories of a martial arts instructor who had newbie students with very little training time spar outright. The results aren't surprising: serious injuries of unprepared and undeveloped students.
Any decent and knowledgeable instructor will know how to gradually introduce “aliveness” to those ready for it since it is as much the end result of one’s dedication and exposure as an attribute of the training program. Simply, it’s a matter of progression to those who can already give and take it.
Whether solo training or with a group, allow me to introduce these three elements of FSD training:
Regimented – That is, it should be structured or have some degree of formal set-up so as to produce tangible results in one’s performance. Your program should allow you to schedule it regularly, have a place or resources set-up for it, and have levels of progression. Be consistent, both in practice and effort. Your security and life deserve more effort than just a passing, half-hearted, hanky panky activity.
Resistance – Semantics aside, this is the core of what the video above tries to present. Adding resistance, which is the element of force and aggression keeps you on your toes and forces you to actually feel and adapt to what might potentially happen out there should you meet trouble. Is it a 100% assurance? No, but it would be better than nothing. The bad guys out there won’t be as polite or as friendly as your sparring or training partner.
Realism – Goes hand in hand with the above. Get acquainted with the environment and settings. The “comfort” and "ease" afforded by a nice, clean mat floor with you dressed in your gi uniform or exercise clothes won’t be the same as out there in the mean streets. The street itself is out to get you, will all its dirt, debris, structures and potential hazards. The more you mimic the conditions you may encounter outside with all its various daily scenarios, the better.