Let us look at strength from a physical standpoint. Strength is a necessity for navigating the earth plane. The muscles must undergo stress to become stronger. Here are some types of resistance training. There are different modalities that can be used for attaining and maintaining strength.
Resistance training adaptations are both chronic and acute. Chronic responses to resistance training are seen in the endocrine, skeletal, muscular neurological, and cardiovascular systems. Acute responses to resistance training occur primarily in the endocrine, muscular, and\ neurological systems. Anthropometric (body composition) adaptations are considered as chronic adaptations to resistance training
a system of conditioning involving lifting weights especially for strength and endurance
Body Weight Training
Bodyweight exercises are strength training exercises that do not utilize free weights; the practitioner’s own weight (body mass) provides the resistance for the movement.
Kettle Bell Training
Requires a cast iron or cast steel ball with a handle attached to the top. It is used to perform many types of exercises, including ballistic exercises that combine cardiovascular, strength and flexibility training.
Indian Clubs are an upper body exercise modality. They force posture without coaching. Indian Club are self-limiting with regard to slouching and posture. Self limiting exercise are simply activities that naturally restrict progression without some degree of physical adaptation.
If you are an office worker, there are exercise regimens available that can be performed at work
There are other modalities that help with strength attainment and maintenance. The ones presented here are just a small sampling. Any modality that facilitates adaptive stress on the muscular system will, in effect, improve strength. Strength maintenance is important for sustaining an active metabolism (i. e.: fat burning activity).
Traditional or untraditional, any system that works for the individual is a good system.