Before you start any outdoor fitness activity, it's important to warm up your body. A dynamic stretch is a great way to do this. Lift your knees toward your chest and continue until you feel warm and start to sweat. It's also important to make sure the warm-up is specific to the range of motion you'll need for the workout.
For example, if you're about to go for a run or do some intervals, you should prepare your hips and ankles and activate your glutes. If you're currently inactive or feel that your fitness level is low, it's highly recommended that you consult a health or exercise professional before beginning the activity. Warming up and stretching your muscles can help prevent injuries, so make sure to take the time to do it properly.