Trainer’s Tips: HIIT It Hard

BY REGGIE EDWARDS | DIRECTOR OF FITNESS

Chances are you’ve heard the hype surrounding HIIT workouts. If you’re not familiar, HIIT stands for High Intensity Interval Training. These workouts are extremely intense and intended to push you to your limits, so the workouts themselves are short only ten to thirty minutes with thirty minutes being on the much longer end of the spectrum. When thinking about HIIT, think sprinting and plyometrics or jumping.

During HIIT, you do twenty to thirty seconds of activity followed by thirty seconds to a minute of rest for the full length of your workout. It’s crucial that you don’t allow your body to rest longer than the prescribed amount of time. A HIIT workout is meant to rapidly elevate the heart rate with only short periods of rest between sets. The up and down spikes your metabolism and results in significantly higher post-exercise oxygen consumption, or afterburn, than a standard steady state workout. That’s a fancy way of saying you continue to burn calories for up to two hours following a HIIT workout because your body takes longer to recover.

A steady state workout is one you can do for up to an hour or so. The intensity level isn’t that high and it remains fairly consistent for the length of your workout. Where HIIT is sprints, steady state is running a few miles at a comfortable pace. With steady state, you’re likely to stay in the fat-burning zone burning calories for the majority of your workout. However, since you’re not pushing yourself to exertion, there’s a faster recovery period and your body doesn’t continue to burn calories for very long after your workout. Since you aren’t pushing yourself as hard, you can do a steady state workout more often than a HIIT workout without risking injury and burnout.

As is true for a lot of things, but especially in the world of fitness, variety is the spice of life. HIIT is not better than steady state nor vice versa. Both offer pros and cons, and both should be implemented if and when your body is ready. How you implement them depends on your goals and level of physical fitness. You’re going to see the most results if you mix them up.

HIIT training is uncomfortable. The workouts are tough and not for beginners; high intensity exercises carry a significant risk of injury if your body isn’t trained properly. You need a cardio background before you dive into a HIIT workout. It’s not a matter of doing steady state or HIIT, but rather training your body to get where you want to be. After all, doing ten squats in a row is very different from doing ten squat jumps.

If you don’t exercise regularly, steady state is the place to start. These exercises put less stress on the cardiorespiratory system while offering increased endurance and stamina and a faster recovery. If you’re doing forty minutes of steady state cardio, you’re likely to spend a solid thirty of those minutes in the fat burning zone while also increasing your slow-twitch muscle fibers. Slow-twitch muscle fibers let us go for a long time, think long-distance or cross country runners, whereas fast-twitch muscle fibers, the kind developed in a HIIT workout, are for explosive movements.

Plateaus are common in steady state exercise routines because people get comfortable and don’t continue to create challenges for themselves. Once you’ve done six to eight weeks of a steady state routine, you’re probably ready to incorporate a ten minute HIIT workout once a week. If you’re hitting a plateau with your steady state exercise, then you’re definitely ready to try incorporating HIIT.

Adding in a short HIIT workout will help prevent boredom and increase your overall physical fitness. Once you’re ready to incorporate HIIT workouts into your routine, experts recommend limiting them to one or two HIIT sessions a week. Pay attention to how long your sessions are, and keep them on the shorter side if you plan to incorporate multiple HIIT workouts each week. Most importantly, pay attention to your body. Some people can do more HIIT sessions than others, and it’s important to be honest with yourself. If you push yourself to more HIIT sessions when you aren’t ready, you run the risk of hurting yourself or setting yourself back due to overexertion.

While steady state exercise taxes the aerobic system, HIIT stimulates both the aerobic and anaerobic systems which means your body has more stamina and performs better in all your workouts no matter what they are. With aerobic workouts, we’re in our fat-burning zone and we can sustain that for a long period of time. Once you go above 85% of your maximum output, your V02 Max, you get to an anaerobic state you can’t breathe, you’re huffing and puffing, you have to stop and slow down. That need to slow down, the thirty second breaks in a HIIT workout, allows you to catch your breath and recover a bit, but it also gets your muscle to a level where your glycogen is depleted.

Glycogen is stored glucose. When you’ve depleted your glycogen, your body is in oxygen-debt and you enter anaerobic metabolism. Anaerobic metabolism can only use glucose and glycogen while aerobic metabolism can also break down fat and protein.

During a HIIT workout, you totally deplete your glycogen levels, meaning you’re completely wiping out your muscles. When you lose glycogen, your blood sugar goes down, and you feel exhausted. So, why is depleting glycogen good? It is only when glycogen is in a depleted state that fat can be mobilized out of storage and used as a primary fuel source. Draining glycogen out of the largest glycogen pools your skeletal muscles is a signal to the body to burn excess fat. For a lot of people, excess fat is stored in the belly which is why HIIT is believed to be more effective at burning abdominal fat than a standard, steady-state workout.

Looking to incorporate a HIIT workout into your routine but not sure where to start? Try this simple cardio interval workout on the treadmill: sprint for 20 seconds, then rest for 40 seconds, alternating for a full ten minutes. When I do this, I set the incline and speed at a fast, challenging pace, then stand on the edges of the treadmill during my rest periods. Another simple HIIT workout is one involving body weight exercises which is great because it can be done almost anywhere. Start with a cycle of push ups and squats. Do 30 seconds of continuous push ups, rest for 30 seconds, then do 30 seconds of continuous squats followed by 30 seconds of rest. Do three sets. Next, do 30 seconds of jump rope or jumping jacks followed by thirty seconds of rest. Repeat four times. That’s ten minutes and you’re done!

If you’re unsure about how to up your workout game, make an appointment with a personal trainer at the Fitness Center. If you haven’t gotten your complimentary fitness assessment, start there so you gain a better understanding of where you’re at on your fitness journey and will be able to safely use the machines in the gym. If you’ve already got a fitness background and you’re looking to take it to the next level, purchasing a training package either solo or small group is a great way to push yourself.

Remember, when you train, you want to fail. When a muscle fails is when it really succeeds. That is, you’re pushing your body to its limits until, eventually, those limits move.