Train like an athlete- You should be training for enhanced performance and your strength work and conditioning/ cardio should be hard, heavy and fast. None of the light weight, slow motion nonsense, and no medium intensity, steady state cardio that drowns your fast twich fibers in lactic acid, making them take on the characteristics of slow twitch fibers.
Use big, full body exercises and add in some throws, jumps or strongman training whenever appropriate. Always strive to increase your performance from one workout to the next by lifting more weight, doing more reps, jumping higher, running faster or getting done in less time. Everybody wants to look like Georges St. Pierre or Gabrielle Reece so why not start training like them?
Use exercises that allow you to move your body through space- When you move your own bodyweight (or bodyweight plus resistance) like you do in a chin up, pushup, squat, etc. you activate more muscle fibers, thus you will get bigger, stronger and leaner a whole lot faster. As far as conditioning and cardio goes, you have to realize that the human body wasn’t designed for repetitive steady state activity but rather short bursts with a wide variety of different movements. This is exactly what you do when you play most sports. When you pump away on a machine for 30 minutes you are fighting evolution.
So focus on bodyweight and free weight exercises like chins, dips and sprints, play as many sports as possible, and avoid all strength or cardio machines like the plague.
Less is more- When training for size, strength and speed, quality is always more important than quantity. If you undertrain you will make some progress, albeit slowly. If you overtrain you will make zero progress. When in doubt, do less.
Eat only organic, anti inflammatory, plant based whole foods- If a caveman couldn’t eat it you shouldn’t eat it. Nothing that comes in a box or plastic wrapper or that contains any artificial ingredients whatsoever should ever touch your lips. Focus on getting the majority of your calories from vegetables, fruits, nuts, seeds and legumes. Add in extra protein where you need it and drink nothing but pure water. Also, try to avoid dairy, corn, wheat, sugar and saturated fat as these cause inflammation throughout the body leading to pain and disease.
Sleep- Getting 8-10 hours per day of high quality sleep is simply the best thing you can do for recovery, building lean muscle, burning bodyfat, improving insulin sensitivity, enhancing immune system function, repairing damaged tissues/injuries, improving brain function, etc, etc, etc. If you are not sleeping you have a major problem and it needs to be addressed with high priority.