WHAT IS HIIT EXERCISE

I speak as a fitness trainer with over 25 years of experience in high-intensity interval training (HIIT). I first discovered this style of training when I joined the Army. At that time, I was quite unfit; I didn’t participate in sports during school and lacked confidence. This was one of the reasons I decided to join in my 20s—I wanted to become a strong and fit individual.

Our daily training sessions included a significant emphasis on fitness, particularly HIIT-based workouts. Remarkably, within weeks, I was fit enough to keep up with all the workouts, and that is when I became a fan of HIIT training.  Throughout my 25 years in the fitness industry, I have consistently used this training style. While it may seem new to some, HIIT has actually been around for a long time. It’s only recently that the fitness industry has officially named and branded it, leading to a growing interest in becoming “HIIT FIT.”

WHAT IS HIIT TRAINING

HIIT, or High-Intensity Interval Training, is a workout method that involves alternating between short bursts of intense exercise and brief periods of rest or lower-intensity activity. For instance, you might perform a challenging movement for 20 to 50 seconds (a short enough duration to push yourself to work hard), then followed by a 10 to 20-second recovery period. And you simply keep repeating this sequence. 

The beauty of HIIT is that it doesn’t need to be high-impact, like burpees. You can incorporate safer and more effective movements that minimise the risk of injuries. Additionally, you can easily adapt the HIIT approach to walking by alternating between intervals of faster walking and slower-paced walking. It really is that straightforward: just short bursts of hard work followed by brief recovery times. One of the best aspects of HIIT workouts is their flexibility in duration, ranging from just 4-20 minutes (& everything in between)

This is my one HIIT home workout, which is featured in The Telegraph as one of the top home workouts. 

NO BOREDOM WITH HIIT EXERCISE

So one of the biggest reasons people give up on exercise is boredom. Whether it’s jogging on a treadmill or following a long workout video, it can quickly feel dull and unmotivating. That’s where HIIT (High-Intensity Interval Training) comes in. It breaks the monotony by offering fast-paced, ever-changing workouts that challenge your body and keep your mind engaged. Because you alternate between bursts of intense effort and short rests, you’re constantly moving through different exercises, which keeps things fresh and exciting.

QUICK HIIT EXERCISE

HIIT also fits well into a busy lifestyle, which adds to its appeal. Most HIIT workouts are short—typically 4 to 20 minutes—but highly effective, and my 7 Minute Workouts have been the most popular with over 160 million views (because we can all find 7 minutes a day to exercise). That means you don’t have time to get bored, and you still walk away feeling like you’ve accomplished something meaningful. This short, intense format naturally appeals to people who struggle to stay motivated or find long workouts mentally exhausting.

HIIT FOR RESULTS

Perhaps most importantly, HIIT offers quick results, which can be a huge motivator. Seeing improvements in strength, endurance, or fat loss makes it easier to stick with the routine. When you feel progress and stay mentally stimulated, working out becomes less of a chore and more of a challenge to look forward to. In short, HIIT makes it easier to stay consistent—and consistency is key to long-term fitness success.

HIIT FOR MENTAL HEALTH

HIIT  also has powerful effects on mood and emotional well-being. The high intensity triggers a strong release of endorphins, dopamine, and serotonin, which can quickly lift mood and reduce symptoms of stress, anxiety, and depression. Over time, HIIT also helps regulate cortisol (the stress hormone) and trains the nervous system to recover faster after stress, making you feel calmer and more emotionally balanced in everyday life. Many people notice an immediate post-workout boost in energy, motivation, and emotional release.

HIIT FOR COGNITIVE HEALTH

HIIT also supports brain health and mental performance. It increases blood flow to the brain and boosts brain-derived neurotrophic factor (BDNF), which helps with brain cell growth, focus, memory, and emotional regulation. This often shows up as sharper concentration, clearer thinking, and improved sleep quality—especially when workouts are done earlier in the day. Better sleep then feeds back into improved mood, resilience, and stress management.

MAIN PHYSICAL BENEFITS OF  HIIT EXERCISE

• Burns more calories in less time – Great for busy people.
• Boosts metabolism – You keep burning calories even after the workout is over.
• Improves heart health – Makes your heart and lungs stronger.
• Helps burn fat – Especially belly fat.
• Builds endurance and strength –  with bodyweight exercises.
• No equipment needed – You can do it anywhere
• Improves insulin sensitivity – Good for blood sugar control.
• Keeps workouts interesting – Fast pace, short duration, and always changing.

SUMMARY: HIIT training involves performing short bursts of exercise lasting between 20 and 50 seconds, where you exert maximum effort. Following this, you have a recovery period of 10 to 20 seconds to catch your breath. That’s the core concept of HIT training.  I  have lots of free HIIT  workouts on my YouTube channel, so feel free to try one now at home with me.