How to improve flexibility is a question that training programs should address. Flexibility is enhanced by muscle strength and endurance, making these relevant concerns to a training program. Flexibility refers to the range of movement that your body performs. Having muscles that are flexible helps prevent injuries and soreness after physical exertion. Muscle endurance is the ability of muscles to perform continuous physical exertion over an extended period of time. The development of slow twitch muscles affects muscle endurance. Slow twitch muscles do not expend large amounts of force, but they can sustain activity for long periods. Developing theses muscles increases the length of time an activity can be sustained.

Stretching exercises increase flexibility. Warm up before stretching by going for a 10 minute walk. Stretch muscles slowly and gradually progress into the stretching position. Stretch until you feel tension, but at no stage should you feel any pain. Hold each stretch for at least 10 seconds. To improve flexibility, make sure that you are performing stretches correctly and that you are stretching the muscles that are your point of focus. Ensure that you stretch both sides of your body.

• Hamstring Stretch - Sit on the floor with your back straight. Extend one leg forward while the other leg is bent, so that your foot touches your thigh. Reach forward, lengthening your back, to touch the toe of your extended foot. Hold for 10 seconds and then release. Repeat, stretching both sides of your body.
• Neck Stretch - Touch your left ear to your left shoulder. Touch your right ear to your right shoulder. Touch your chin to your chest. Repeat.
• Quadriceps Stretch - Stand up straight. Bend your left leg up behind you, using your left hand to grab your ankle and pull your leg towards your buttocks. Hold for 10 seconds and then repeat using the right leg.
• Arm Stretch - Extend your left arm. Place your right hand on your left elbow and pull your left arm towards your chest. Hold for 10 seconds, then release and repeat.
• Thigh Stretch - Sit down on the floor with the soles of your feet touching each other. Gently lean forward until you can feel tension in your thighs.
• Knee Lift - Lie with your back flat on the floor. Lift your knees chest. Use your arms to pull your legs toward your chest.

Muscle endurance can be improved by engaging in cardiovascular activity. Begin by walking to build up fitness levels. Progress to running 20 minutes at least three times a week. As your fitness increases, extend the distance that you run and the pace of running. To improve endurance, incorporate hills into your running route to help increase muscle strength.

Muscle endurance is increased by progressively overloading muscles. If you're weight lifting to improve muscle endurance, decrease the weights you are lifting but increase the number of repetitions that you perform. You can also increase the number of sets that you perform and decrease rest periods in between sets. Depending on experience and ability, aim to perform 15 to 20 repetitions with sets of 3.