I live by the non-aggression principle, the idea people should be free to do whatever they want as long as they do not initiate the use of force or fraud against others and that force is only morally justified when used to stop or prevent the initiation of force by another person or group. Also, the level of force you use in defense must be appropriate for the threat. If you use too little force your defense will be ineffective and you may be seriously hurt or killed. If you use more force than necessary to stop the threat or continue to use force after the threat has been stopped you risk serious legal repercussions like being sentenced to prison or facing a civil suit for damages. If you are attacked you should not cause more harm to your attacker or attackers than is necessary to effectively stop them from harming you.
While training and experience are often the most important factors, your level of strength and conditioning has a huge impact on how effectively you can use force and how well you can scale it to the threat. It may sound counterintuitive, but the stronger and better conditioned you are and the more effectively you can use force the less you will have to use in many situations.
For example, imagine if on a scale of one to one hundred with one being light touch and one hundred being lethal force you were attacked by someone using a level of force of seventy. To effectively stop the threat your force must be at least at the same level. If you are not capable of using that level of force you will need a weapon, a force multiplier, to effectively stop the threat.
The use of most weapons, especially edged weapons and firearms, raises the level of force all the way to one hundred. If you are physically incapable of using the necessary level of unarmed force to stop the threat you would be justified in using a force-multiplier even if it meant greatly exceeding the level of force of the threat because it would be your only effective option. In this case, insufficient strength and conditioning forced you to use a higher level of force (weapon) to effectively defend yourself.
Consider the effective options of people with different levels of strength and conditioning under similar circumstances. If a man in good physical condition with basic self defense training is the target of an unarmed assault by a violent criminal of similar size he should be capable of matching the force of the criminal’s attack and either stopping it or creating an opportunity to escape. Under the same circumstances a man in poor physical condition would be less capable and may have to rely on a weapon to effectively stop the threat.
If your only effective option is lethal force you would be morally justified in using it, and for a lot of people under a lot of circumstances lethal force is the only option. Regardless of their training and experience if you put a small woman, a frail elderly person, or a disabled person in the same situation their only effective option will be to use a weapon. If that’s the case and they have to kill the criminal to defend themselves that’s fine, however if you are capable of developing a level of strength and conditioning that would improve your ability to effectively scale force enough to avoid having to use lethal force under some circumstances it is worth it to do so.
This is especially true if you are a law enforcement officer since you have a duty to act, unlike us civilians who may have the option to disengage and escape some situations. While many officers will face situations involving such a huge disparity of force that lethal force is the only effective option, there are also many situations where superior physical strength and conditioning would allow an officer to subdue a threat without the need to shoot them. If there’s no other option I’d rather see law enforcement officers go home and criminals go to the morgue at the end of the day and not the reverse; however, I suspect many would prefer to avoid this and having to deal with any investigation as well as all the second-guessing by the media which is largely ignorant about use of force.
Let it be perfectly clear that contrary to the old saying, violence absolutely does solve things, but only if you’re good at it (the people who claim it doesn’t usually are not). While training is definitely the biggest factor also being as strong and well conditioned as possible can make a big difference, and if you want to be capable of using the least amount of force necessary to stop an attack without hurting anyone more than you have to you should continuously work towards becoming stronger and better conditioned.
For information on how to effectively, safely, and efficiently maximize your strength and conditioning check out my books High Intensity Workouts (for free weights and machines) and Project Kratos (for bodyweight).
For those interested in more information on the subject of effective self-defense I highly recommend the following books: