Get fit quick with high intensity training

Inactivity is the world's fourth-biggest killer and two-thirds of people are not physical enough for good health. If you're one of the quarter of Brits who only walks for an average of nine minutes a day, it's time to get active.

High intensity exercise

Pic: Corbis

While walking is the best form of exercise, especially for those who aren't used to fitness, interval training which involves short bursts of high intensity activity, will help you get fit quick.

Whatever your preferred method of cardio exercise, running, cycling, or swimming, interval training not only varies your routine but also saves time and helps you push your fitness to the next level.

What is interval training?
Simply put, it involves short bursts of high-intensity cardio followed by gentler 'recovery' periods. Professional athletes and trainers regularly use interval training because of its effectiveness but it provides a great workout whether you're relatively new to exercise or desperate or play competitive sport.

How does it work?
Short bursts of intense exercise push your heart and lungs to work harder, which ultimately improves your cardiovascular fitness. As you increase the length of the high-intensity intervals your muscles will gradually become more tolerant to the tell-tale lactic acid burn, thereby improving your stamina and enabling you to train harder for longer.

What are the benefits?
The benefits of interval training are numerous. The body's ability to use oxygen during exercise is significantly increased. Your heart will also benefit. As it becomes stronger with interval training, its efficiency, the amount of blood your heart pumps with each beat, increases, bringing down your resting pulse rate.

There's a good chance you will burn fat faster too. Carbohydrate reserves (glycogen) within the muscles are quickly depleted with high-intensity exercise. When these reserves are exhausted, the body calls upon a replacement - fat. That means that even after your workout, your body will continue to burn fat as it replaces the glycogen.

Interval training also means you can reach peak fitness without spending hours at the gym. Research at the McMaster University of Hamilton in Ontario Canada found that participants who embarked on an interval training regime for one and a half hours a week achieved the same results as those doing regular cardio for five hours a week.

What do I do?
You don't have to be a professional athlete to benefit from interval training but if you are a beginner it is essential not to push yourself too hard.

For example, if running is your chosen cardio exercise, you may want to start with three minutes of jogging followed by one minute or even 30 seconds of high intensity running. The low and high intensity intervals can then be repeated three times. In the early stages it is advisable to take a rest day in between sessions.

As you build endurance and cardio fitness, you will find you are able to increase the length of the high intensity work and reduce the low intensity jog. As with any exercise, a five minute warm-up is essential if you are to avoid damaging your body, and a five-minute cool down will gradually bring your heart rate down to its normal level.

For the already fit interval training fan, Tabata, founded by Izumi Tabata in Japan, is a high intensity interval training method for which you will need to be physically fit. Though it lasts just four minutes, the Tabata method involves bursts of extremely high intensity exercise, including barbell squats, push-ups, chin-ups and sprinting.

Whatever your fitness level or reason for trying interval training, it is recommended that you seek professional advice from a personal trainer who will be able to set a regime to suit you.