This is a follow-up post to a blog post on HIIT (High-Intensity Interval Training) I recently wrote for my friends at bevegt (direct link here). Since the original was in German and herbiwarrior is a bilingual blog I’m giving a short recap before diving into the details, so you can skip ahead if you read the article over at their page.
Part I – Advantages and method of HIIT
HIIT is a training method that makes it possible to achieve big results with very little input. The principle behind it are short,very intense training sessions, approximately 20 minutes in length. In recent years the method has been studied in detail and proven by sports medicine. Athletes from all disciplines, from weight lifters to runners, can profit from doing HIIT
The advantages of HIIT
If you ever asked yourself why Olympic runners are that buff, the answer is: growth hormones. Every form of training is an impulse for the body to adapt and grow stronger in order to better withstand the demands of training. Sprints shock the bodily system way more than moderate running, which ups the excretion of hormones responsible for growth (according to a study from 2002 by up to 450 percent). Convenient side effect: This process not only increases the muscles used during sprinting, but all other ones as well.
People trying to lose weight often hear the advice “Fat burning only starts after 30 minutes of training”. For this reason, cardio training was long seen as the way to get in shape. In reality interval training at high intensity is an even bigger fat killer.
Due to the level of intensity, a lot of calories are already burned during training. In the 24 hours after the workout, your fat-burning furnace is still ramped up and to a higher degree than after moderate training. Growing muscles additionally contribute to the level of calories burned in daily life.
Long-distance runners can also profit from HIIT. Contrary to what you would expect, this method is very suitable to improve your endurance. This is probably due to the improved ability to break down lactic acid build-up within your muscles and use fat depots for fuel. The effect: you can run longer and faster before fatigue and pain set in. According to studies, two weeks of interval training can improve aerobic capacity (the ability to run with sufficient oxygen) as much as six to eight weeks of normal training. In a study from 2008,2.5 hours of sprint training produced similar physical changes as 10.5 hours of classic cardio.
Including HIIT in your training schedule
A session of HIIT consists of several short intervals at high intensity, alternated with longer rest periods. The goal of the training intervals is to get into the anaerobic zone (when your muscles are slowly running our of oxygen). The rest periods are used for complete recovery before the next sprint.
The length of the sprints and breaks as well as the number of intervals are dependent on your level of motivation, energy and training. Therefore sessions will be different for individual. It’s important to experiment and rely on your intuition.
An example session would look like the following:
5 minutes warm-up (light jogging or jumping jacks)
6-8 sprint intervals of 15 seconds (slowly increase the speed)
1 minute rest in between each
5 minutes cool-down
Time altogether: about 20 minutes
You can adjust the times to your level as needed. If you feel like you can handle more, run longer and/or more often. For beginners three to four intervals is enough. Sprint sessions of this kind can be done every seven to ten days. Us the same rule as during single sessions: pay attention to your own level of motivation and capabilities and make sure you recover properly in between workouts. HIIT should not be underestimated and your body needs to regenerate.
Part II – The finer points of HIIT
HIIT is not only super effective, it’s also a lot of fun. I for one have been a convert ever since my first session. However, correct sprint training is more than putting on your shoes and starting to run. Paying attention to some details can help you really unlock the potential of HIIT.
Sprints are an art in themselves and call for a different technique than jogging. Proper form is important not only to run faster and further, but also to avoid injury.
Hold your body upright – The upper body should always be oriented forward. Avoid sideways movements of the hips or shoulder belt. You back remains straight, your gaze forward.
Swing your arms straight – Don’t let your arms cross in front of your body but swing them back and forth on the side of your body parallel with the opposite leg. The movement is generated in your shoulders, the elbows remain in an angle of about 90 degrees.
Relax – Try to relax all muscles that are not needed to propel yourself forward. This saves energy and allows you to run faster and longer. Arms, hands, face and jaw muscles should all stay loose. Look at pictures or videos of Olympic runners during a race and you will see how soft and relaxed their hands and face muscles are.
Use your legs correctly – Pay attention to make your strides short and fast instead of long to avoid injury. The leg movement should be similar to that riding a bike. Hips stay straight, knees are pulled upwards, and your heels should almost touch your behind.
Run on the balls of your feet – Striking the ground with your heels is not even a good idea while jogging and should therefore be especially avoided during sprint training. Take care to use the balls of your feet. That way the impact force impact is absorbed by all the muscles in your feet instead of your knees.
Breathe – Running this fast your body needs a lot of oxygen, which is why breathing right is imperative. Don’t give in to the temptation of shallow breathing or holding your breath. Inhale deeply and powerfully and concentrate on a forceful exhalation.
Fill up your muscle tanks beforehand: HIIT is very very energy-consuming and you need to make sure your body gets enough calories. If you are livin’ la vida low carb and attempt your first sprints, you might find yourself out of breath and energy very quickly (unless you are incredibly adapted to using fat as energy, which very few people are). So make sure to fill up your muscles tanks with enough fuel.
Does that mean stuffing your face with candy bars, toast bread and other simple sugars? No, your friends are bananas, brown rice, and quinoa. If you fail to fuel up, you not only risk not finishing the workout but losing some of your precious muscle.
Increase your energy intake post-workout: Be ready to eat a lot more in the days following HIIT sessions. When I do HIT with weights (note the missing I? no intervals here, just heavy-duty lifting), I need to eat like it’s a hobby in the following three days. Seriously. Don’t underestimate your body’s fuel needs with this kind of workout.
Do you know what you need to do after training hard? Rest harder. Your body needs to regenerate. Muscles, joints, ligaments – everything needs a break to repair the damage. The same is true for the central nervous system. Training at this intensity is a shock that it needs to deal with first. Have you ever gone through a rough workout one day and weren’t able to lift a thing on the following day even though you were training a different muscle group? Fatigue of the nervous system in action.
So rest, rest, rest. It’s very important to be honest with yourself and respect your body’s needs. When motivation and energy have returned, it’s time for the next session. In the meanwhile don’t be too hard on yourself if the couch is your best friend for a while.
People who have cardiovascular problems, are untrained, or have other conditions that don’t allow training at high intensity should avoid HIIT. When in doubt, always talk to a doctor first.
To make the training less demanding, beginners can start off by running uphill or do interval training on an exercise bike. Soft, even ground helps reduce the danger of injuries. Short-cut grass or sand are ideal. Avoid obstacles, including rabbit holes.
Timer – Of course during a workout that is time based, it makes sense to have a means to measure the length of your intervals. There is a number of apps out there for that (for iOS, Android, and both). I also hear good things about this device called gymboss. If you are not into that newfangled technology, and old-school stop watch will work too.
Protocols – If you are the type of person who likes to adhere to a given plan instead of experimenting for themselves, there are a few proven protocols for HIIT out there that you can try. These can also be used as a basis to develop your own plan. Also check out this great HIIT infographic over at greatist.com
HIIT can take your training to the next level. Whether you are an endurance runner or weight lifter, every kind of athlete can profit from this approach. While it is demanding and therefore not for everyone, it’s well worth trying out. And remember: It’s not about speed or covering a lot of distance. What’s important is to give it your all, to test your own boundaries, and last but not least, have fun.
Have you tried HIIT and can share your experience? Did it improve your training? Tell us about it in the comments.