We’ve all seen those guys at the gym who hit the free weights of hours and the people who get on a treadmill every day for 45 – 60 minutes at the same pace day in and day out. Neither of those options appeal to me every day. Don’t get me wrong, strength training and cardio are important, in fact, steady state cardio for me being a runner is VERY important some days, but if you want to get the biggest bang for your buck, burn some fat, and get your heart rate elevated you have to HIIT it! The Tabata workouts I’ve talked about frequently fall into this category. Check out my Tabata intro post and my Treadmill Tabata post for more on that version of HIIT.
What is HIIT?
HIIT stands for High Intensity Interval Training. The basic principle of HIIT is working your body hard and fast for a short burst, then giving it a bit of a rest with an active recovery period. For instance, sprinting for 30 seconds then jogging or walking for 1 minute would be a standard rep set. That example would give you a 1:2 ration of work to rest ratio while Tabata, by comparison, is a 2:1 work to rest ratio. You would repeat this process a number of times to get the best workout.
Benefits of HIIT
HIIT training offers many important benefits. Your legs will be worked hard with a HIIT workout. Unless you want bulging leg muscles, you shouldn't need to do strength training for your legs if you perform HIIT training a few times a week. And HIIT increases your body's fat burning potential. Doing the intense intervals causes fatty acids to be released into the bloodstream. HIIT training also increases the level of HGH in your system. HGH is a hormone that promotes fat burning yet preserves muscle. To top it off, HIIT training creates an after-burn effect (EPOC) which lets your body burn more calories for hours after you have finished exercising.
Weaknesses of HIIT
HIIT is not a perfect system. A big disadvantage is that this cannot be done every day. It is easy to over train your body if you're doing strength training for your leg muscles in addition to HIIT. If you have worn your muscles out the day before, you should engage in a slower, steady state cardio workout instead.
Sprint Interval Length
You can vary some of the stages of your HIIT training routine for a more effective workout. First - change the length of your sprint intervals. Doing shorter intervals of between 15 and 30 seconds gives you more of a chance to exert yourself while sprinting. This increased exertion will help release more HGH into your system. And a shorter sprint interval releases more fatty acids into your bloodstream as well.
Example: I did a variable HIIT session where I ran a steady state cardio in one minute increments and alternated sprint speeds from 20 – 45 seconds throughout the 20 total minutes on the track. I then ran another 25 minutes of steady state cardio followed by 5 one minute wind sprints with 15 seconds rest in between.
Working harder for longer than 30 seconds requires more effort. The longer intervals will burn more calories. And exerting yourself for a longer period depletes the level of glycogen (carbohydrates) in your system, encouraging your body to burn more fat after you have finished your workout.
The length of your recovery period is also important in HIIT training. This is the lower exertion part, walking or jogging, of your workout that gives your muscles a moment to recoup. You spend a certain amount of recovery time relative to the amount of sprint time. If your sprint interval is 30 seconds and your recovery interval is also 30 seconds, you have a 1:1 ratio. If instead, your sprint interval is 15 seconds and your recovery interval is 45 seconds you have a 3:1 ratio.
The more time you give your body to recover compared to your sprint intervals (a ratio of 2 or 3:1) the more effort you will be able to give in the next sprint. The more exertion, the more HGH your body can release. And giving yourself a longer recovery interval will reduce the risk of over-training your muscles.
Using a shorter ratio of sprint to recovery results in glycogen depletion, lactic acid buildup and a more efficient after-burn effect. The risk of over-training is increased though. Tabata falls into this category.
Best Cardio For Weight Loss
I think that the best cardio for weight loss combines various HIIT training routines to give you all of the benefits, a strong HGH release, fatty acid release, calorie burning and glycogen depletion. Your workout should start with the short sprint and long recovery ratio part of the HIIT routine.
Another Example: A sprint of 15 seconds and then recovery period (walking or jogging) of 45 seconds is appropriate. This is the method that will release fatty acids and increase the level of HGH into your system. Take 2 minutes to warm up, then perform this HIIT routine 8 times, for a total of 10 minutes. Similar to the above example you use the second part of your workout to recover and burn off fatty acids in your system. The second part of my workout is 25 minutes of steady state cardio (an exercise bike, treadmill, elliptical, or light paced jogging). The final portion of your workout is doing long interval HIIT with short recovery intervals. This depletes the glycogen in your body, which then means you will burn more fat once you have finished your exercise. I combine 1 minute of sprinting intervals with one minute of jogging or walking. You won't want to exert yourself so much for the sprint intervals here as your muscles will already be tired. This final portion should be about 10 minutes as well.
Nutrition Note: Because of the amount of glycogen your body will be burning off, make sure you eat a combination of protein and carbohydrates before you workout to make sure you have the energy (carbohydrates) and the muscle protecting nutrition (protein) in your system before you get started. I have a Whey protein scoop after I workout to make sure I get about 25 grams of protein in my system within 30 minutes of finishing!