Your fitness program should always be based around longevity, sustainability, and movement. The only exception to this would be if you're an athlete who gets paid extremely well to perform at the highest level of your sport. I'm going to go on a limb and say that the majority of you reading this aren't professional athletes, which means this post is for you!
Your fitness program should be designed to enhance the quality of your life. Fitness is about improving your life and building a healthy/functional body and mind. Stop focusing on aesthetics, achieving the "perfect body", or maintaining single digit body fat. When you focus on those things too much, you start making your life about achieving those goals ... rather than using fitness to enhance your life. Your life and body are temporary things, they wont last forever. But, the time you do have should be spent enjoying life with a body that allows you to do what you please. How can you be living your life to the fullest if you're always in the gym spending hours on your physique? How can you experience all life has to offer if you're avoiding social events because of extreme nutritional restrictions? How can you remain active if you're always placing aesthetics over function and improved movement/mobility? You can't!
Health is not just physical, it's mental and social as well. SO WHAT if you're physique is amazing?! If you're obsessing and only thinking about workouts/nutrition and missing out on social events because of your fitness program ... guess what? You're not healthy at all! Fitness should fit into your life, your life shouldn't have to fit into your fitness program.
What's a healthy fitness program based around? Three things. Longevity, sustainability, and movement.
Longevity: Your program should be based around improving your body and keeping it that way forever! It should focus on improving mobility, flexibility, and functional strength. It should be designed with the future in mind. This means your program should be designed to keep you moving well and in great shape at the age of 50, and not just looking great at the moment. Make sure your workouts are loaded with a quality warm up, lots of mobility work, and exercises that are designed in a way that builds your body up, not break it down. The same goes for your nutrition! Your diet shouldn't be about bulking, cutting, carb loading, or any other bull shit like that. Those are all short sighted and not about longevity. You nutrition should be something that can be done for the long haul. Base your nutrition around real foods and avoiding made made junk. No one ever got fat from eating lots of veggies, fruit, meat, and healthy fats/nuts.
(Coach Steve Maxwell in his 20's and now in his 60's has always based his programs around longevity, sustainability, and movement. He says he was never concerned with building a beautiful body. But he certainly achieved one none the less.)
Sustainability: Fitness programs should be sustainable. Programs that have you always pushing to lift heavier, move faster, or beat records are not sustainable. Those programs are great for athletes, but not for the average person looking for real health. Your workout should be based around movements that you can do forever at almost any place at any time. Your program should also take frequency into account. A program that has you training twice a day, or working out every single day for multiple hours is not a sustainable program. Programs like this eventually lead to burn out or over training, something certainly not desirable when looking at training for actual fitness. Your body needs time to rest, recover, and deal with the stress of regular life. Training a little less will sometimes yield much better results than training too often.
(An 80 year old woman in China who has always trained for life, movement, and continued strength. Sustainability is key!)
Movement: Your training should always be based around improved movement, or maintaining your bodies ability to move with ease and efficiency. This means learning how to push, pull, lunge, squat, crawl, invert, bridge, run, and more. This also means you should focus on improving these movement patterns and the flexibility, strength, and mobility that comes with each. Avoid machines, learn how to move your own body weight, and then venture into other forms of fitness such as barbell training or kettlebells if you desire. But always, always, base your workouts around movement. If you don't move, you lose your ability to move. Life is about movement, not doing endless curls at the gym.
If you follow this method, your body will thank you with long term mobility, strength, and ease of movement. Also, the sexy/lean body is just a bi-product of a healthy life style! When you train for longevity, sustainability, and movement your success is guaranteed ... without all the unhealthy obsession.