It’s that age-old Texan wisdom. Use it to your advantage.
“If you always do what you’ve always done, you’ll always get what you’ve always got.” — Anon
Remaining healthy involves developing a proactive attitude towards life, the self and others. This attitude can be the driver for, and indeed the result of maintaining sustainable healthy habits over a period of time.
One of the key ingredients is consistency. There are many helpful habits listed here in this thread relating to nutrition, sleep and regular exercise, and all of these are tremendously important features of what many call a healthy life. You have asked about ‘remaining’ healthy and fit, and the key to this is consistency.
Accountability and self-honesty facilitate consistency when it comes to setting goals and designing personal healthy habits.
For example, if you would like to put into practice some of these salubrious behaviours, such as maintaining a predictable sleep schedule, or exercising on a regular basis, then make yourself accountable to somebody else. Conscript a friend to train alongside you, and to keep you honest to the promises you make to yourself. However ultimately, this drive and determination to be consistent must come from within. And it will in time, if you practice discipline and self-honesty.
Trite though it might be, keep in mind that you will have off days. And these are okay. As long as you are able to pick yourself up and go again when next you have the opportunity to prove the point to yourself.
Also consider why you want to be fit and healthy. Is it for you, or is it because you want to be able to play with your kids, and even meet your grandkids one day? These broader reasons will help feed your ambition and keep you on task when the going gets tough.
At the end of the day, success begets success. Establish for yourself what it is you need to do in order to be able to achieve the goals you seek (in this case, it might be as simple as setting an early alarm, or getting to bed earlier), and hold yourself to that.
Encourage friends to join you in your pursuits, and remember that good health isn’t a destination, it’s the journey that counts.