High Intensity Interval Training: How Much is Too Much?
What is HIIT?
High Intensity Interval Training (HIIT) is the workout of the moment and has been growing in popularity for the last few years. Not only is it an efficient way to exercise, taking anywhere from 15 to 45 minutes per session, but it also involves mixing strength and cardiovascular training in one intense session. HIIT involves pushing your body to its limit in any given exercise for a short period of time, for example 45 seconds, followed by an even shorter period of rest, such as 15 seconds. The interval sequence is repeated with the same or different exercises for the set period of your workout.
Why is it so popular? The Benefits of HIIT
When you push your body to its limit during HIIT’s short intense bursts of exercise, not only do you use a huge amount of energy, but you increase your metabolic rate for up to 24 hours afterwards due to the fact your body’s repair mechanisms are in overdrive. The high intensity of the workout increases the need for oxygen in the body and this requirement for oxygen continues once the workout has ended. This means that your body creates an after-‐burn effect or “excess post-‐exercise oxygen consumption”, which means your body continues to burn fat and calories at a high rate even though the workout is over. This in turn speeds up your metabolic rate making HIIT one of the most effect exercise structures for weight loss.
HIIT is also an extremely efficient way to increase your anaerobic capacity, as short bursts of intense exercise, followed by only brief rest, keeps your heart racing. These improvements to your metabolism, aerobic fitness and strength can all be achieved in a short amount of time, which makes HIIT a great form of
exercise when you are short of time and want a big energy boost! Some studies even claim that HIIT is anti-‐aging because increased oxygenation can have benefits at a cellular level!
HIIT is not only great for weight loss but it is also a great way to keep exercise interesting and fun and the endorphin hit can become seriously addictive! You can also keep this form of training interesting by incorporating a different piece of equipment each session, such as intervals based solely on the use of kettle bells or resistance bands.
But How Much HIIT is Too Much?
HIIT workouts sound intense – and they are! In a time when health experts are constantly saying that most people are not getting enough exercise and are constantly being encouraged to move more, can this be a bad thing? The effectiveness of HIIT workouts is in the fact your body is placed under significant stress for a short period of time and therefore must adapt by increasing your fitness or building your strength.
However, recent research suggests that pushing the body too far too puts people at risk of developing serious health issues, beyond just fatigue from overtraining and the subsequent risk of injury. When the body is being pushed very hard in the “working” periods of HIIT, it is under significant stress. Placing the body in this state of stress too frequently or for too long can lead to imbalances in cortisol and other hormone levels, potentially leading to conditions such as hypothyroidism or aggressive immune responses as a result of excess stress.
Warning signs that your are HIITing it too hard
Overtraining of any sort can lead to a general feeling of fatigue and sluggishness, indicating that the nervous system is exhausted. Difficulty in maintaining form and control when carrying out movements is indicative of this, and can lead to serious injury, setting your training back significantly.
Experiencing gut health issues or weight gain is also indicative that you may be hitting the HIIT sessions too hard as high levels of cortisol can lead to permeation in the gut lining, which is only one cell thick. This in turn can lead to inflammation in the body due to toxins getting into the blood stream from the gut, which can lead to food sensitivities and poor mental health. Difficulty sleeping is also indicative that you are training too hard, as a solid HIIT session should encourage a deep, restful night’s sleep.
Get the Balance Right
So what is the best way to approach a training regime involving HIIT? If your goal is to gain muscle mass, HIIT is only necessary one to two times a week depending on your goals, as overdoing it can lead to muscle atrophy and the intensity with which the working periods are meant to be approached means that any weights used will not be as heavy as when training for mass gain.
For most people, it is recommended by the American College of Sports Medicine that two to three HIIT sessions a week is enough to get the maximum benefits of the sessions, but to avoid injury, fatigue and too much stress on the body. These sessions should not be taken consecutively with a day of rest or training in a different way in between. HIIT training a couple of times a week, in combination with weight training and some lower intensity sessions such as yoga, is the best way to get the most out of your training program to reduce fat, improve fitness and strength, and still maintain your overall health. Ensure that you are getting enough rest between sessions, and you will see fantastic results!