How often should I do this core workout?

Two to three sessions per week, performing the exercises as a circuit with minimal rest for 2-3 rounds.

Do I need any equipment for this core programme?

No. The programme consists only of bodyweight exercises and can be performed at home, outdoors or at the gym. A weight plate, dumbbell or medicine ball is optional for the Russian twist.

Is the programme suitable for beginners?

Yes, the article states the programme is suitable for both beginners and advanced trainees.

How do I make the exercises harder without adding weight?

Take longer to lower the upper body and hold the contraction for a couple of seconds at the top in sit-ups, perform the exercises more slowly, or increase the time under tension once you can complete three rounds with good technique.

What is the abdominal vacuum used for?

It is used to gain better control over the abdominal wall and activates, among other things, the transversus abdominis. It is not a strength exercise in the same way as sit-ups or planks, and it does not reduce fat around the stomach.

How is the Plank to Hip Raise performed?

Hold a forearm plank with the body in a straight line for 15 seconds, then lift the hips upwards and lower them back to the plank position 15 times, and finish with a further 15 seconds of plank.

What should I do if my lower back lifts off the floor during Alternate Straight Leg Lower?

Stop earlier in the movement. The lower back should stay against the ground throughout.

15-Minute Workout Program for a Stronger Core | Hardworkout Magazine

Key takeaways

- A complete core workout can be done in about 15 minutes using bodyweight only, with no equipment and no gym.

- The core includes the rectus abdominis, the internal and external obliques, the transversus abdominis, the erector spinae, the diaphragm and the pelvic floor muscles, which together stabilise the spine and transfer force between the upper and lower body.

- The programme is performed as a circuit of five exercises for 2-3 rounds, two to three times a week.

- The abdominal vacuum trains control of the abdominal wall and activates the transversus abdominis, but it does not reduce abdominal fat or make the waist itself narrower.

- Visible abdominal muscles require core training to be combined with regular strength training and a diet tailored to your goals.

A strong core is about much more than visible abs. The muscles in the abdomen, back, and hips contribute to better stability, power transfer, and control in both strength training, running, and everyday movements. You also don't need a gym or advanced equipment to train your core effectively.

What does this 15-minute core workout involve?

This 15-minute program consists only of bodyweight exercises and can be performed at home, outdoors, or at the gym.

About the program

- Goal: Strengthen the core muscles and improve stability and body control.

- Level: Suitable for both beginners and advanced.

- Duration: Approximately 15 minutes.

- Equipment: None.

- Frequency: 2-3 sessions per week.

- Execution: Perform the exercises as a circuit training with minimal rest between each exercise. Complete 2–3 rounds.

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Why train the entire core?

The core consists of several muscles in and around the abdomen, back, and pelvis. Together, they help control movement, stabilize the spine, and transfer force between the upper and lower body.

The main muscles have different functions:

- Rectus abdominis (the straight abdominal muscle): Bends the upper body forward and helps control the position of the pelvis.

- Obliquus externus and internus (external and internal oblique muscles): Assist in rotation and lateral bending of the upper body.

- Transversus abdominis (the deep abdominal muscle): Lies beneath the other abdominal muscles and helps stabilize the abdomen and back.

- Erector spinae (the back extensors): Extends the back and helps keep the spine in the desired position.

- Diaphragm and pelvic floor muscles: Help regulate abdominal pressure, providing support around the spine when you lift and move.

The core therefore has different tasks depending on what you are doing. In sit-ups, the abdominal muscles create movement in the upper body, while in the plank, they primarily prevent the pelvis and lower back from changing position.

In squats and deadlifts, the core helps keep the upper body stable while force is developed through the legs and hips. During running, it helps control the pelvis and upper body from step to step.

Training Program

Exercise 1: Situps

Repetitions: 15

- Lie on your back with your knees bent and feet flat on the floor.

- Tighten your stomach and lift your upper body controlled towards your knees.

- Keep your feet on the floor throughout the movement.

- Lower your upper body back to the starting position in a controlled manner.

- Avoid using momentum to come up.

If you want to make the exercise more challenging without extra weight, you can take longer to lower your upper body and hold the contraction for a couple of seconds at the top.

![](https://hardworkout.no/wp-content/uploads/2026/09/ChatGPT-bilde-30.-sep.-2026-111229.png)

Exercise 2: Alternate Straight Leg Lower

Repetitions: 15 per leg

- Lie on your back with both legs straight and lifted towards the ceiling.

- Keep one leg still while you lower the other controlled towards the floor.

- Stop just before the leg touches the floor and bring it back to the starting position.

- Keep your lower back against the ground throughout the movement.

- Stop earlier if your lower back starts to lift off the floor.

You can switch legs for each repetition or perform 15 repetitions with one leg before switching.

![](https://hardworkout.no/wp-content/uploads/2026/09/ChatGPT-bilde-30.-sep.-2026-111351.png)

Exercise 3A: Side Plank with Hip Dip

Repetitions: 15 per side

- Place your forearm on the floor with your elbow under your shoulder and extend your legs out.

- Lift your body so that you are in a side plank with your body in a straight line.

- Lower your hip controlled towards the floor.

- Lift your hip back up until your body is back in the starting position.

- Keep your upper body stable and avoid rotating forward or backward.

Complete 15 repetitions before switching sides.

![](https://hardworkout.no/wp-content/uploads/2026/09/ChatGPT-bilde-30.-sep.-2026-111432.png)

Exercise 3B: Russian Twist

Repetitions: 15 per side

- Sit on the floor with your knees bent and lean your upper body slightly backward.

- Lift your feet off the floor and keep your legs together.