Which exercise to choose at your beginning stage of fitness without enough flexibility, stability or strength? Any other practice you are doing besides running? Here are four exercises for beginners. 

Exercise 1. Flexibility    

Hamstring + calf stretch

Hamstrings are the muscles along the back of your upper leg, they run from the thigh to the knee. They help you to bend your knee and move your hip. These muscles are used when you are running or playing sports

The calf muscles are along the back of your lower leg. They help move your heel during activities such as walking, running, or jumping.

To stretch both muscle groups together:

1. While standing, place your right foot in front of you.

2. Hinge (bend forward) at the waist to lean your torso forward toward the extended right leg, and bend your supporting knee.

3. Slowly flex your right ankle so that your toes are pulling up toward your body.

4. Hold for a cycle of relaxation breathing and then repeat with the left foot.

Exercise 2. Core muscle stability

Crunch

Crunches are a great core-strengthening move. Byraising your upper body,you are working out and strengthening your abdominal muscles.

If you have lower back pain, do crunches with care. Do this exercise more slowly and start with are smaller number of reps.

1. Start by laying your back. Bend your knees and plant your feet on the floor at hip width. Line up your head and spine. Cross your arms across your chest.

2. Tighten your core and relax your neck and shoulders. Tuck in your chin and lift your upper back, keeping your lower back, pelvis, and feet on the floor. Pause.

3. Slowly lower your upper back to return to the starting position.

4. Start with 1 set of 8–12 reps.

Or you can try the Plank.

Plank

The plank is a full-body exercise that targets your core, it also strengthens your arms, shoulders, back, glutes, and legs.

1. Start on all fours, with your hands below your shoulders and your knees below your hips.

2. Straighten your legs behind you, keeping your feet hip-width apart. Tighten your core.

3. Hold for 10–30 seconds.

Tip: to make this exercise easier, place your knees on the floor.

Exercise 3. Upper Body Strength            

Bicep curls to overhead press

Although you can use dumbbells for this exercise, it can be just as effective with household items like a bottle of water. This exercise primarily focuses on your bicepmuscles but also works your deltoids and core.

1. Stand with your feet hip-width apart and your back straight.

2. Hold your householditem or weights in one hand with your palm facing forward and your arm extended down to your side.

3. Keep your elbow close to your body as you curl your bicep — lifting the object to your shoulder in a controlled motion.

4. Then, turn your hand outward so your palm and wrist are pointed toward the ceiling as you press the object upward above your head. Extend your arm all the way to the top.

5. Slowly bring your item back down the same way you came until your hand is at your side in the starting position.

6. Complete 8 reps with one arm then switch.

7. Aim for 3 sets on both sides.

Tips: For better results, gradually increase your reps over time.

Exercise 4. Leg strength           

Squats

The basic squat is one of the best exercises to tone legs. It also sculpts the butt, hips, and abs.

Squats are ideal if you have back problems. Since they're done while standing up and without extra weight, they won't strain the back.

To perform a basic squat using only your own body weight, follow these steps:

1. Stand tall with your feet spread shoulder-width apart. Choose a foot direction that is comfortable for you.

2. Tighten up your core to stabilize yourself, with your chest thrust upward, start to shift your weight back into your heels while pushing your hips behind you as you squat down.

3. Continue to lower yourself until your thighs are almost parallel to the floor. Your feet should remain flat on the ground, and your knees should remain over your second toe.

4. Keep your chest lifted and your feet on the floor, and exhale as you push yourself back up to standing.

5. Do 12-15 reps.

Tips: For balance or extra support, perform your squats while standing alongside a wall or next to a chair or the edge of a table with one hand on the object. Resist the urge to pull on it or push off from it.