Example: Becoming a Better Hiker
The level of hiking you aspire to will obviously affect the fitness demands of the activity. However, no matter what type of hiking you're thinking of, there is certainly stamina that is required.
For improving stamina, you can incorporate cardio into your exercise week. It can be a blend of longer, slower sessions alongside some shorter but more intense sessions that include interval sprints. All of those workouts will certainly help improve your stamina in order to make your hikes more enjoyable and open up the options of hikes that you will be equipped to handle.
You also will want to work on strength, especially in your legs and core. Squats, lunges, deadlifts, hamstring curls, step ups and calf raises all will assist in your leg strength. You can include movements like that a couple of times per week, sprinkling in some upper body lifts for balance.
For fortification of your core, planks, crunches, clamshells, glute bridges, and supermans all will come in handy to help. Improving core strength will help your balance and will really come in handy if you are carrying a heavy pack. These moves can be incorporated 3-5 times per week.
Developing or maintaining flexibility and mobility will be paramount. Depending on where you're at with those issues, you might include some stretching sessions, yoga classes, or time with the foam roller/massage stick/tennis ball to release tight tissues. Some folks can get away with just addressing this once a week, while others need it just about daily for best results. You can choose to spend just 5 minutes on flexibility and mobility at a time if you like - consistency is more valuable than duration of each session. But if you have the time to do a full hour or more, great! More power to you.
All of the above attributes help with balance, something absolutely critical for hiking. When you have good balance, you will be able to stay safe and avoid falls.