Tempo's trainer Sarah doing a HIIT workout

If jump-starting your workouts is your focus for 2022 – HIIT is a great place to begin.

High-intensity interval training, or HIIT, is a form of physical training that intersperses short periods of intense exercise with periods of rest or less intense exercise. The aim is to get your heart rate up quickly, improve blood flow and oxygen to your muscles, and burn more calories. It is an effective way to burn fat and calories in a short period, and the best news… HIIT can easily be modified for people of all fitness levels.


Why is HIIT more effective at burning calories and body fat?

During high-intensity interval training you can burn more calories than more traditional workouts and raise your metabolic rate. One study has shown that high-intensity interval workouts burn 25–30% more calories than other forms of exercise. HIIT also increases your resting metabolic rate, so you can burn more calories once your workout is complete. 

Due to increased oxygen consumption, HIIT may also change your body’s metabolism so that fat is burnt for energy, therefore, lowering your total body fat. A 2019 review in The British Journal of Sports Medicine concluded that people who did HIIT regularly lost 28.5% more fat than people who did moderately-intense steady-state types of exercise, like running. 


What are the other health benefits of HIIT?

We’ve already learnt that high-intensity interval training is great at burning calories and fat, but what else can this type of exercise do for you?

HIIT can improve your mental health

All exercise helps stimulate our happiness hormones – serotonin and endorphins, balancing our mood and well-being, which is one of the reasons you leave a training session feeling great. Vigorous exercise can also increase levels of neurotransmitters, which manage chemical messaging in the brain, and raise BDNF, a protein that helps regulate brain function and mood.

HIIT can keep you young

Levels of HGH (the Human Growth Hormone) are raised during high-intensity exercise. This hormone is produced by the pituitary gland and plays a significant role in growth, body composition, cell repair, and metabolism. A new study from the Mayo Clinic has demonstrated that HIIT can also reverse some types of cellular ageing. 

HIIT can increase your strength and muscle mass

Some workouts can cause you to lose muscle as well as fat. HIIT, however, can maintain your muscle mass by training them to recover and rebuild during short periods of rest, which helps to build strength quickly.

HIIT can increase your anaerobic capacity and aerobic capacity

More traditional forms of exercise may only increase your aerobic capacity. However, vigorous exercise can also increase your anaerobic capacity – which is paramount to your overall health.

HIIT can improve cardiovascular health and lower cholesterol

Bursts of high-intensity activity can optimise your heart health over a shorter period by improving its structure, such as chamber enlargement, which increases the volume of blood the heart can pump to the rest of the body in each heartbeat. A HIIT workout can also incorporate weight training – combining these is one of the most effective ways to optimise fat burn and improve the health of your heart.

HIIT can lower your blood sugar and blood pressure

The short bursts of vigorous activity in high-intensity interval training can be very effective in how the body uses and stores blood sugar, compared to the effectiveness of steady-state workouts. HIIT may also improve insulin resistance, which is hugely important for individuals with Type 2 diabetes.

As we age, our arteries tend to stiffen, which leads to higher blood pressure. HIIT helps the blood vessels relax, which may improve blood pressure.


HIIT improves your stamina

HIIT works on the principle of adaption. The body adapts to the strain it’s put under to improve its ability to cope, and by increasing your heart rate, your lungs and muscles will learn to adapt to the challenge. Exercises will then become more effortless, and you will also be able to maintain speed and exertion during other forms of exercise.

HIIT is the most time-efficient workout

The NHS recommends we do at least ‘150 minutes of moderate-intensity activity a week, or 75 minutes of vigorous-intensity activity a week’. Many may find they are not meeting this due to time constraints. The intensity of HIIT sessions means they can be as short as 20 or 30 minutes but are the same or more beneficial than prolonged periods of moderate-intensity exercise. Maintaining a HIIT regime might be a more manageable option for anyone struggling to find time to exercise. Doing HIIT sessions 2 to 3 times a week is a great routine to build.


How to get the most from your HIIT workout

Here are 6 top tips for turning up the intensity of your training:

  1. Push yourself
  2. Don’t sacrifice form
  3. Fuel your body for more intense workouts
  4. Warm-up well
  5. Stay focused
  6. Find the right schedule for you