Your body will continually adapt to what you do, all the time. Moving will allow your body to adapt to what it's supposed to do, which is move. Not to mention all of the other benefits, which are stronger bones, muscles, heart, lungs, and overall resiliency.
No matter who you are, there is something innate within you that enjoys moving. The trick is to find what you enjoy and pursue improvement in that thing. Being goal oriented is good, but that is not the correct foundation if your goal is lifelong health.
Of course, enjoying what you do does not guarantee a healthy body. The good news is that most activities people enjoy provide improvement in the direction of health with some blind spots. So, some extra goals to keep in mind are developing cardiovascular fitness, strength and bone density, and mobility. A strong foundation in these will give you an incredibly able and resilient body.
As always, seek out information and strive for improvement. It doesn't matter how you develop these attributes, as long as you do. Movement is not a recipe, but a journey of learning and growth. Do activities that make you want to continue doing those activties and everything else will follow if you are striving for improvement.
Move around and get your heart rate up. Breathe heavy, get your blood flowing, and feel the endorphins you get from pushing your blood around. Cardio should feel good! It doesn't have to be hard. Go on a walk, bike ride, swim, play some pickleball, or whatever else gets your blood moving.
Cardio can be difficult, and it should be if you are trying to improve as fast as possible. However, consistency is much more important than difficulty when it comes to cardiovascular health. Get into the habit of doing some easy activity that moves your blood 3+ days per week, preferably something that you enjoy and makes you feel good.
Strength is important for resiliency. Being strong means your bones are strong and muscles can output a lot of force. The most efficient way to develop this is through resistance training, which I recommend to everybody. I realize that not everyone enjoys resistance training, though.
Most activities make you stronger in a specific way, but there will be areas that will be underdeveloped. For example, running greatly improves leg strength and bone density, but the upper body doesn't get much stimulus. If you don't like resistance training, I would just ask that you recognize your weaknesses and do what you can to address them.
Mobility should be a constant. If you are not exploring your range of motion to its fullest extent, you're going to lose it. This is why you should find ways to use your full range of motion in your daily life. Picking something up? Drop into a deep squat or stretch your hamstrings to reach the ground. Watching TV? Explore ranges of motion and get to know what your body can do. Be creative and appreciate the mobility that you have.
I love working out. Movement has become one of my deepest intellectual pursits. I've probably put more effort into improving my movement than I have into anything else. Through this journey, I have developed a lot of ideas on how to level up. Here is my ever-evolving collection of thoughts about training to progress beyond the basics.
Increasing the frequency that you do a movement allows you to learn the movement much more efficiently. It allows for more opportunities to practice in a given time which leads to more practice overall.
High frequency also allows for fast physiologic changes. It sends a message to the body that it should always be ready to do this specific movement so the body spends more time in a state that is ready for that movement. This allows for less required warm up time and pushes the body to move towards that state as a homeostasis.
In order for high frequency training to be effective, each session should be light enough so that you don't feel fatigued for the next session. Or, if that's unavoidable, the fatigue should not affect how you do the movement.
Intensity is necessary for making big physiologic changes. Intensity is a large stimulus that takes a long time to recover from but sends a powerful signal to the body for change. This is best used after a high frequency period of a similar movement because the body is ready for that high intensity and primed to make a big change.
It's important to make sure you recover from high intensity sessions and still incorporate low intensity sessions in the training. High intensity does nothing but damage if recovery needs aren't met such as nutrition, sleep, and low intesity sessions.
Tendons exponentially multiply the amount of power you are able to output. Think of muscles as the activation energy required to produce force with tendons. The stronger and bouncier your tendons are, the better you will perform in almost any activity.
This is not to downplay the importance of muscles. Tendons are attatched to muscles, so if the muscle isn't strong enough to withstand the force of the tendon, the energy will dissipate into the muscle and no external force will be created. Tendons and muscles work together, but muscles are much easier to improve. This is why most training is focused on muscles.
There are ways that people train tendons, though. Tendons respond very well to high frequency training, dynamic training, and nutrition. Moving in a dynamic way frequently will train the tendons and muscles to work together to create a bouncier system. Supplying the nutrients like collagen will also encourage tendon development, although this still happens much more slowly than muscle development. Drinking bone broth and eating cartilage/connective tissue will provide the most complete nutrition for tendon development.
Building off of the importance of tendons, the next level up is the importance of cyclic motion. Think of a bunjee jump. Jumping off puts energy into the system, and that energy is conserved and reapplied every time the jumper bounces up and down. If we apply this to the higher-dimensional space of the human body, cyclic motion will take the energy that we apply and conserve it within the body for repeated application.
Running is a very good model for this. If you observe an efficient runner, their upper body is dynamically moving in a cyclic way to conserve and repeatedly apply energy into the ground. The more efficient this is, the less energy they have to expend to propell themselves forward.
Strength is a function of muscle size and the amount of the signal to contract. So if you are able to send more signal to your muscles, you can be stronger without making any physical muscle gains. The importance of neural output is commonly downplayed in favor of hypertrophy, but being aware of this mechanism for strength can make a big difference.
An easy way to train your nervous system is to frequently work up to high output, being careful to balance fatigue and soreness. You don't want to go too hard such that your neural output suffers for the next session, but you do want to slightly overload your nervous system.
Nutrition makes a world of difference in optimal performance and recovery. See Principles of Nutrition to understand more about my ideas for nutrition in general. In terms of performance, the trick is to listen to your body and try new things. Typically, 100 calories of easily digested food per hour of cardio works well. However, knowing what makes you feel best takes experimentation. Being able to tell when you are in need of some more fuel, water, electrolytes, or are just tired is an invaluable skill to maintain good performance.
Training sessions in the gym will level up performance no matter what kind of athlete you are. To get the most out of a gym session I usually format like this:
This allows for the best performance in the things that need the most coordination and neural output and saves the less consequential movements for the end. Of course, there are so many ways to structure a gym session that work, but in general know what the goal is and structure according to that.
With enough intention and effort, you are able to change your physiology. Feet can become more arched, joints can move better, and muscle can change types. It's all about what your body thinks it wants to do. Physiology ties in with perception and the signals your brain sends, so in order to change what your physical attributes are the brain has to start sending different messages. Again, this is different for everybody but it is possible.