There are as many weight loss and exercise plans as there are opinions; everyone has something that they swear works.
If participating in martial arts and not a huge fan of weight training to improve, there are a ton of alternatives. Although martial arts are great exercise by themselves, for those that only practice casually and wish to improve their body condition by other means as well, there are many great and fun ways to work train. Join a recreational sport and, before you know it, you'll be see improvements in your martial discipline as well as your health. the following are some suggestions of sports that are fun, different and will improve strength and endurance; unquestionably important when practicing martial arts.
If you love martial arts, the thrill of parkour ( http://en.wikipedia.org/wiki/Parkour) might be for you. Parkour, or freerunning, is a style of obstacle course training with the simple goal of getting from point A to point B in the simplest way possible using only your surrounding environment and the human body. Usually the paths are not simple and require strength, speed and agility to complete. Modern free runners typically practice in outdoor environments like playgrounds, streets and urban areas with interesting and difficult terrain. Professional practitioners of parkour are famous for their extreme jumps, lands and creative movement over, up and through seemingly impossible terrain. The range of movement required of this interesting sport makes it great strength training.
Rock climbing, or bouldering, is another exciting sport that invokes a full body work out. Rock climbing is the general term for climbing either natural or artificial climbing apparatus using harness and ropes to assist. Bouldering is the technical term for rock climbing without the use of harness or ropes, though those athletes that participate in this extreme branch of the sport usually use climbing shoes and chalk on their hands to minimize slipping. Less extreme forms of bouldering will see climbers move horizontally instead of vertically, this takes as much skill and strength while removing the danger. Both form a full body workout that strengthens the core, arms and legs, great for martial artists.
Tennis and other racquet sports train reflexes and agility at the same time as being an intense cardio workout. Tennis is less of a strength training exercise as it is cardio workout, and you can plan on burning between 300 and 400 calories in an hour of tennis, depending if you're playing singles or doubles (singles is a more intense workout since you don't have help!)
Kayaking and rowing in general are fantastic upper body workouts. Kayaking has the benefit of more fast paced action, depending on the speed and difficulty of the water you're traversing. Shooting rapids in a kayak will naturally release adrenaline which raise heart rate and will burn more calories than boating on calm water.
Field sports like football, lacrosse, rugby and ultimate Frisbee are more traditional but will get you running and are great social activities requiring teamwork. Although filed sports don't necessarily give as much upper body training, they are wonderful cardio exercises that will elevate heart rate and get you sweating. You could just go running or cycling, but the social aspect of team field sports can not be ignored; there is just something about playing a game with a bunch of mates that builds camaraderie.
Sports are a great way to improve general health by increasing endurance and strength. For a martial artist, each of these sports can be part of a weight loss and exercise plan to help you become a healthier person.