Sprint, rest and repeat. Maybe the simplest training routine you’re likely to hear, but science shows it could also be the most effective. High Intensity Interval Training typically involves exercising at a high intensity for 50 to 90 seconds followed by a period of low intensity training or complete rest which lasts 50 to 120 seconds. You then repeat this for a total of 10 to 20 minutes on your weapon of choice whether that’s a bike, a treadmill or just on your lonesome up and down a hill.
Why? Well we’ve five reasons…
#1. Lose Fat in Less Time!
Firstly, as a training concept, HIIT arguably shot to fame in 1994 when scientists from Laval University in Québec, Canada compared a 15-week high-intensity interval-training program to a 20-week endurance-training programme. After taking muscle biopsies and body fat measurements what they found was the HIIT program increased the body’s metabolism which resulted in greater fat loss. Concluding, “The metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favour the process of fat loss.”
Put more simply, HIIT burns more fat in less time.
#2. Get a FREE Diet Pass!
If you complete a brutal HIIT workout you can eat what you want. No seriously! Research published in the Journal of Applied Physiology found your body’s ability to absorb, store and assimilate carbohydrates — even sugar-ridden ones — is vastly improved after a HIIT workout.
Making you less prone to storing them as fat.
This all because it improves the efficiency your GLUT-4 glucose transporter. A protein that helps the transportation of sugar and glucose around the body. Again, put simply HIIT now, eat later.
#3. Bigger and Quicker Muscles!
Sports science teaches us that within the human body there are two type of muscles fibres. These can be classified as fast twitch muscle fibres and slow twitch muscle fibres. In short, slow twitch muscle fibres are smaller in size and great for endurance-based events. Fast twitch muscle fibres are much larger and needed for strength, speed and power events.
But sporting benefits aside, know a greater proportion of the latter will help you fill a t-shirt better and tends to look better on the beach. So how do you get them? Yes, you guess it: HIIT. That’s because researchers at the Department of Clinical Physiology in Stockholm, Sweden, found, “It is possible to achieve a fibre type transformation with high-intensity training.”
#4. Raise Testosterone!
Chop those lengthy morning runs in favour of a short, sharp HIIT workout. That’s according to a study published in the Journal of the American Medical Association that showed male long distance runners had, “significantly lower” testosterone when compared to other male test subjects. All of which spells bad news for your sex drive, muscle recovery and overall energy levels.
Worth stating is there are of course many benefits to any and all forms of cardio and when devising any routine you have to consider all the physiological adaptations. But specifically regarding your testosterone, twig and two berries — and based on the previously mentioned study — it might be best to bust out some HIIT rather than a daily, mini marathon.
#5. You Become Fitter!
This last one sounds so simple, but hear me out. In very basic terms, exercise can be classed as aerobic and anaerobic. Aerobic actually means, “With oxygen” and relates to exercises where we must breathe to do them. As an example imagine trying to complete a 10km run or 800m swim without oxygen. Impossible! Hence why these are aerobic exercises. Anaerobic exercise relates to those shorter, quicker activities that don’t need oxygen like a 50m sprint, squat or bicep curl. All of which can be done without breathing. Hence why these are anaerobic exercises.
Now “fitness” can be a very broad term with many different components. But for a good level of “fitness” it’s safe to say you need both a good aerobic and anaerobic capacity. Which is why scientists at the Department of Physiology and Biomechanics wanted to test the, “Effects of moderate-intensity endurance and high-intensity intermittent training on aerobic fitness and anaerobic fitness.”
The result? Well contrary to popular belief they found, “That moderate-intensity aerobic training that improves aerobic fitness does not change anaerobic capacity and that adequate high-intensity intermittent training may improve both anaerobic and aerobic energy supplying systems significantly.” In simple terms what this means is a steady, 1-mile jog will improve your aerobic fitness, but not your anaerobic fitness. But a HIIT workout — sprinting up and down hills — could potentially improve both.
Of course if you just enjoy a slow, steady, Sunday jog who am I to argue? But to specifically improve both your aerobic and anaerobic capacity studies show it might be better to HIIT.