Figure out what matters to you personally and frame exercise in terms of a means to achieving or aiding you in that matter. For example, if family is important

Figure out what matters to you personally and frame exercise in terms of a means to achieving or aiding you in that matter. For example, if family is important to you, being strong and fit makes it easier to take care of a young family. If you're a woman I assume pregnancy goes easier if you're physically robust beforehand. Good health ensures longevity and gives you more and better quality time with your family. If your career or work is important then you can note that being in better health puts you in a better position to achieve your professional goals - lower chances of RSI or lengthy hospital stays, easier to put in long hours without getting tired. And of course physically fit people are more attractive and, on average, attractive people do better professionally - they get paid more, are perceived as more competent etc. If you care about the environment, becoming fitter makes it more likely you'll walk or bike instead of driving. You'll also require less healthcare in your old age, which means fewer resources are expended on you. I could keep going - practically any personal goal could get a bit of a boost from better health.