Running has a reputation for causing injuries, but is safe for joints as long as you have strength and flexibility around the hips, knees and ankles.
Do the following exercises three to four times a week.
Single leg glute bridge Lie on your back with one knee bent and one leg raised. Keeping your shoulders and your standing foot on the ground, raise your bum, pushing the sole of your raised foot towards the ceiling. Do between 10 and 25 reps for three or four sets on each side.
Reverse lunge off a step Standing on a low-level step, step back with one leg, bringing that leg down to a lunge position so that both knees are at 90 degrees. Spring back up to the start position. Do three or four sets of between 10 and 20 reps on each side.
Deadlifts Hold a weight of between 10-60kg in your hands, with feet just past shoulder-width apart. Keeping your back straight, bend the body from your hips and reach your arms to the floor. Tense your bum as you pull back up, engaging hamstrings. Do three or four sets of 15 to 20 reps.