Type of climbing should be noted: rolling, steep, endless, elevation gain, grade. Heavy climbs require stronger legs, glutes, and core as well as greater stamina. If hills are incorporated too early in the season injury is higher.
2. Monitor your time and have a plan.
Decide on an out and back route or a loop route and stick to scheduled time. It is easy to get distracted and lose time when you are running trails. Don't get caught in the "just over the next hill," scenario.
3. Create a communication detail.
A fishing license will provide you with free search and rescue if you injure yourself in the backcountry. Run with a buddy when you can. Always let someone know where you are running and time you plan to be back. Cell phones don't always work on the trails. Carry a whistle, if you get lost or separated then send out short quick whistle blows.
4. Carry plenty of water and fuel.
Studies have shown that a camelback makes hydration more successful. Endurance gels taken consistently provide muscles with the fuel needed for long runs. Hydration and nutrition are key principles in endurance training programs.
Great advice, especially for those just starting out using hiking as a way to get in shape.
Monitoring your time can also be a really great way to see improvement in your fitness. It's such a satisfying feeling when one makes it to a further point in the same amount of time as the fitness level increases just by staying with a plan.