If your goal is "increase useful lifespan" the list of of fitness goals is nearly inexhaustible. You're optimizing too early, and your target goal is too abstr

If your goal is "increase useful lifespan" the list of of fitness goals is nearly inexhaustible. You're optimizing too early, and your target goal is too abstract. Consider grabbing some more near-term goals (ones that will also contribute to "increase useful lifespan") and pursue those. To share a personal example: signing up for a long race gave me concrete goals with a deadline, I could measure my progress in distance and time, and by the time I completed the race I began to enjoy running for the sake of running. Now I have an enjoyable hobby that also contributes to "increased useful lifespan".