Most people are classically biased toward one of the three legs of the fitness triad: progressive resistance training, cardiovascular training or diet/nutrition. How many folks try and lose weight by dieting and dieting alone? A safe bet would be a majority of individuals. Ever wonder why people who lose a lot of bodyweight rapidly still look fat? It's because they are still fat.
When the human organism perceives starvation it reverts to a primordial hardwiring that seeks to preserve body fat (the last line of defense against starvation) at all costs. So dieting alone can results in weight loss but when more muscle than body fat is lost as a result of crash dieting, the end result is not all that impressive.
I had a self-indulgent buddy who balloon up from 200 to 350. He eventually went on some sort of weird diet and lost back down to 200. He looked terrible, loose skin, still fat and to make it all worse he was now a 'diet expert' and told me and anyone else within earshot how stupid they were to follow any diet other than the one he had used. Of course he still couldn't catch a ball or walk up a flight of stairs without getting totally gassed.
At the other extreme I knew a really good long distance runner who was thin as a rail, lived on carbs and eschewed lifting or protein. He became anemic and emaciated the combination of mega-miles and carbs and fruit in meager amounts produced a physique that resembled a famine victim. Lifting weights to his way of thinking would add muscle that he would have to haul around and would have the same impact as wearing a backpack with a 10 or 15-pound plate in it. Needless to say by the time he got to his mid-thirties he started experiencing the usual repetitive motion injuries ? knee arthroscopic surgery, ankle ligament damage, eternal shin-splints. He eventually had to give up running altogether.
My third example is a former national level powerlifter; a man who set regional records and grew gargantuan. Eventually he weighed 350 and was able to squat over 900-pounds. He ate everything in sight and had to quit lifting altogether when he developed terrible circulatory problems.
Each individual I referenced took one particular leg of the fitness triad and because of overemphasis turned the pursuit of their specialty into something opposite of fitness & health. Better to practice a little of each leg of the triad instead of emphasizing one aspect to the exclusion of the other two. It makes perfect sense when we are presented with extreme and obvious examples.
Marty Gallagher is a former fitness chat columnist for washingtonpost.com. He is also a former world champion powerlifting coach. Marty has written for publications such as Muscle Media, Muscle & Fitness, and Powerlifting USA. His website, http://www.martygallagher.com, assimilates years of accumulated knowledge from the athletic elite and makes them accessible to the common person. The "Purposeful Primitive" way has been proven effective time after time after time for weight loss, building muscle, increasing strength, and improving health.