It’s no surprise that high-intensity training has ranked as one of the top fitness trends worldwide for the past five years: Known as HIT, high-intensity training is an incredibly powerful tool that gives you back significantly more in terms of health and fitness benefits than the effort required.
Unfortunately, either due to a dislike of exercise, a misunderstanding of what it takes to lose body fat, or a mental block, most people neglect the most valuable tool available: Intensity.
What does it mean to incorporate intensity into your training?
Intensity refers to the workload used during training. In a lab, it is often measured by power output or by rating of perceived exertion in practical settings.
The most effective way to incorporate high-intensity work loads into training is to use an interval format in which you perform heavy bouts of work interspersed with rest.
For weight training, intensity refers to the weight lifted during the exercise. It is expressed as a percentage of your 1 rep max (known as 1RM), which is the maximal amount you can lift for one repetition. For most purposes, higher intensity training (HIT) is anything over 80 percent of maximal.
When it comes to cardio exercise, training at a high-intensity means you are doing intervals in which you exert a near maximal effort for a set period of time alternated with rest. Active rest is recommended because high-intensity efforts produce significant metabolic waste including lactate and hydrogen ions that make your muscles burn, and active recovery helps to remove those byproducts so that you can perform another high-intensity bout.
What about training programs that use moderate intensities (in the 60 to 80 percent range) with little to no rest? Can these be considered HIT?
Technically, this would be called moderate-intensity interval training, however, the limited rest periods rev up the body’s oxygen use and place significant metabolic stress on the muscle tissue—a combination that is effective for elevating metabolism, building muscle, and producing significant strength and performance adaptations. This type of training has a high degree of difficulty and is physically and mentally challenging, so people refer to it as “high-intensity.”
It’s okay to refer to this type of training as HIT, but it’s worth remembering heavier, higher intensity workloads produce greater benefits in terms of strength, fat loss, and muscle, even if longer rest periods are necessary. A common mistake people make when designing HIT workouts is to use rest periods that are too short so that power output and intensity degrade and the workout devolves into an ineffective aerobic workout that produces diminishing returns. We’ll show you how to properly design HIT workouts at the end of this article to ensure you avoid this pitfall.
Ten Benefits Of HIT Training
Over the past ten years, thousands of studies have revealed a slew of health and body composition benefits from HIT. Not only is high-intensity training effective, but it’s fast and varied, yielding results in less time than and with more novelty (less boredom) than conventional modes of exercise. Check it out:
#1: Protect Your Metabolism Against Diabetes & Insulin Resistance
The surging rates of obesity, diabetes, and metabolic health problems have led science to explode with studies into the preventative effects of HIT. Working muscle requires a massive amount of energy, while simultaneously sensitizing tissues to bind with insulin. Training with high-intensities is especially effective because it taps into both the aerobic and anaerobic energy systems, requiring the body to burn both fat (during rest periods) and carbs (during work bouts).
As you get stronger and lean tissue grows larger, insulin receptor sites also increase, and your metabolism improves. This is a game changer for many people who suffer from metabolic inflexibility, or the inability to burn body fat and use insulin effectively, due to the combination of sedentary lifestyles and diets high in refined foods.
#2: Raise Metabolic Rate For Easier Weight Management & Fat Loss
The number one reason for the surge in popularity of HIT over the past decade is due to its utility as a fat loss tool. There are several ways HIT promotes weight management: First, the intense anaerobic efforts used during work bouts put the body in oxygen debt, which raises energy expenditure during the post-workout recovery period so that people burn more calories.
Second, HIT builds lean mass, increasing your body’s resting metabolic rate so that you burn more calories over the course of the day. This is especially important because steady-state aerobic forms of exercise degrade lean tissue, leading to a long-term reduction in calorie needs.
Finally, HIT raises levels of fat burning hormones like growth hormone and testosterone, while helping to reset metabolic health with greater insulin sensitivity and metabolic flexibility.
It should be noted that as helpful as HIT can be for weight management, it will have little effect if you don’t pay careful attention to what and how much you are eating. Its impossible to out-train a bad diet, no matter how intense your workouts are.
#3: Improve Muscle Mass & Bone Strength
If getting toned or putting on muscle are a goal, HIT is the way to go because it stimulates protein synthesis and raises anabolic hormone that promote recovery. Weight training with high intensities is especially effective, targeting higher threshold motor units in the muscle that remain untapped unless you stimulate them with heavy loads. Interval workouts that use resistance, such as a resisted bike, hill or stair sprints, or pushing a weight sled are other ways to maximize muscle and lean tissue benefits.
#4: Increase Mood, Self-Confidence & Well Being
Overcoming physical challenges is a fantastic way to build self-confidence and it also pays off by raising mood and sense of well-being by improving brain chemistry.
High-intensity efforts raise body temperature, which has a surpassing mood boosting effect, but they also improve release of feel-good, endorphins that convey a sense of euphoria and overall well-being. The body’s stress response is also enhanced, allowing for the adrenal glands that release cortisol to become more responsive when your fight or flight system is revved up.
#5: Increase Strength & Coordination
An important principle of exercise science is that muscles have motor units that are recruited sequentially, depending on the degree of overload they experience. If you only train low intensities, lifting light weights or doing slow cardio, you never tap into the higher threshold parts of the muscle, and over time, your strength and coordination deteriorate.
HIT is the perfect solution, overloading those harder to reach motor units so that maintain your ability to move quickly and reactively. The cool thing about HIT, is that intensity is relative. Therefore, even if you are a complete novice, you can reap the benefits by training high intensities that are relative to your abilities. And although it’s worth incorporating intensities of 80 percent or greater, studies show that moderate intensities trained to failure are also effective for stimulating higher threshold motor units and building muscle.
#6: Improve Blood Pressure & Heart Function
It was previously believed that low-intensity aerobic exercise was necessary to protect the heart (hence the term cardio for modes like cycling or jogging), but more recent research shows HIT is often more effective.
For example, one study in overweight women showed increased stroke volume (the amount of blood pumped from the heart with each beat) and lower training and resting heart rate after 4 weeks of sprint cycle training compared to low-intensity exercise. A similar 2008 study showed greater flexibility of the blood vessels and less chronic inflammation that damages heart function from HIT compared to aerobic training.
#7: Improve Hormone Balance For Better Libido & Reproductive Health
Most people associate the boost in testosterone that comes from HIT with muscle mass, but studies show that this small exercise-associated increase in testosterone has minimal impact on how buff you are but a more powerful impact on libido and reproductive health. In addition, HIT lowers inflammation that affects reproductive organs, improving the health of male sperm and the female egg. HIT has also been shown to help balance female hormones, resulting in fewer symptoms of PMS and menopause.
#8: Improved Cognitive Function & Less Chance of Brain Disorders Like Alzheimer’s
Most people are surprised to learn that HIT has powerful benefits for the brain. Higher training intensities lead to greater improvements in neuromuscular function, strengthening the connection between the brain and the muscle. HIT also lowers inflammation in the brain and raises levels of a protein called brain-derived neurotropic factor (BDNF) that helps protect the brain from plaques and the related degeneration that leads to Alzheimer’s.
#9: Improve Athleticism & Work Capacity
While long training runs are necessary if you’re going to run a marathon, most of us don’t require that degree of endurance. Fortunately, we can get equal or greater endurance benefits from HIT exercise that typically takes half the time of long, slow, steady state workouts. This is because repeated intervals at a high intensity lead to the following adaptions:
The stimulate improvements in mitochondria—the energy powerhouses that keep us invigorated and help slow the aging process.
They require the body to use energy more efficiently by tapping into body fat, thereby preserving glycogen (that your muscles burn for energy) and prolonging work capacity.
They produce a more responsive central nervous system so that you feel more energized in everyday life and during exercise.
They increase the body’s ability to remove waste products during exercise, leading to a 50 percent increase in what is called the muscle buffering capacity.
#10: Save Time While Building Mental Toughness
The number one excuse most people have for not exercising is lack of time. It’s true that when training at lower intensities, you have to devote considerable time to get measurable results.
The beauty of HIT is that best results come from a short total training time. You can’t keep up the level of effort necessary for much longer than 20 minutes even when active rest periods are included. Of course HIT is physically challenging but this shouldn’t deter you. Studies show that people tend to enjoy HIT as much or more than lower intensity workouts, likely due to the fact that they know their efforts will pay off.
Additionally, the fact that they are setting a challenge and then vigorously working towards increases feelings of satisfaction and fulfillment. You accomplish something not many other people can do, while shaping a body you enjoy and protecting your health and well-being for years to come.
How To Get Started:
Getting started with HIT takes some planning. You need to perfect technique on whatever exercises you choose to perform and it’s important to design workouts correctly so that you overload the body with intensity and recover effectively. Therefore, we have written several articles to get you started.
This article provides five tips for designing successful HIT workouts for fat loss.
And this article provides an overview of factors to consider when designing HIT workouts as well as a sample of popular workouts from studies.