Fitness and Workouts

3 Mistakes You’re Making During HIIT

Ahh, HIIT. The best thing to happen to fitness since running shoes. A workout that promises all the benefits of steady state cardio, but in half the time (or less!). We live fast-paced lives and a workout that claims to cut down on the time we need to spend in the gym will definitely draw some attention.

HIIT, or High Intensity Interval Training, gained popularity a few years ago, and unlike many fitness fads, has continued to be a go-to training method for many of us. It was even ranked one of the Top 3 Fitness Trends for 2017 by the American College of Sports Medicine. And for a good reason, because unlike so many of those fads that eventually wind up on the heap of ‘crap that didn’t work’ (I’m looking at you Shake Weight), HIIT actually has some decent science to back it up. Researchers have been studying the benefits of Interval Training for awhile now, and this type of workout does show it’s superiority over the same amount of steady-state cardio when it comes to improving aerobic and anaerobic fitness, as well as other metabolic markers such as blood sugar levels and cholesterol. Which is fairly logical considering the harder you work, the more demands you put on your body, leading to adaptations to meet those demands. It is also reasonable that in some studies, HIIT led to more fat loss vs Steady State Cardio, perhaps due to increased energy demands during and after the workout (called the Afterburn, or EPOC effect. You can read more about that here). For runners, Interval Training is also a fantastic method for improving speed and endurance when training for a race.

So, we know interval training is good, and can be a great way to get a good quality workout done in a short period of time. But, it is also easy to do interval training incorrectly. There is a multitude of variations in the way a person can do an interval training workout (for example with sprints, on a bike or rowing machine, or with strength-based exercises), but the key feature is that during the workout you’re alternating between work and rest periods; getting your heart rate up then recovering. Seems simple, right? But how long are the intervals? How high does your heart rate need to go? How long should the rest breaks be?

Today I’m sharing with you the 3 biggest mistakes I see people making in their Interval Training, and how you can fit HIIT into your training schedule to get the most benefit.

1. Rest breaks are too short

If the benefit of HIIT is that you’re running REALLY fast compared to doing steady-state cardio, doing more running REALLY fast running should be even better right?


A lot of people think that during a HIIT workout the idea is to go as hard as you can as fast as you can for as much of the workout as you can. In reality though, those recovery breaks are important for getting your muscles and brain ready to go again on the next interval. If you do an all-out sprint, take ten seconds to catch your breath, then try to do another sprint at the same speed, its likely that you’re just going to fizzle out and be unable to keep the pace. Each rest period should be at LEAST as long as the work period, but often times it should be even longer. If your heart rate is completely recovered within a minute of completing the interval, maybe it’s time to push yourself a bit harder during the next work period.

2. Intervals are too long

There are styles of interval training that work within the 1:1 work:rest ratio that include intervals that are 3-5 minutes long. These workouts definitely serve a purpose, but for most people who are short on time and want the best bang for their buck at the gym, a shorter, more intense interval is the way to go. You should be getting your heart rate up to about 80% of your maximum heart rate (or up to a level where you find yourself unable to speak). Since this level of intensity is far too high for us to maintain for any length of time, a shorter work period (1-2 minutes max) is the best use of your time. If you are new to exercising, 80% of your max heart rate can feel very uncomfortable. It is important to start slow and work your way up to intervals like this one.

3. Doing HIIT too often

This is a biggie. We love that all-or-nothing mindset, where if Interval Training is good for us, it’s the only workout we need. But, intense exercise like this is a stress on the body, and just like anything other intense workout we need to alternate it with easier ones for the best results. That means doing a HIIT workout once or twice per week, but the rest of the time doing strength focused workouts, and some light or moderate cardio for balance (You can read more about how much exercise you really need here). Doing HIIT and only HIIT can actually slow down your progress. You might lose muscle mass, feel fatigued all the time, and even increase your risk of injuries. Leave a few days between HIIT sessions to ensure a proper recovery.

Personally, I like to use HIIT as my ‘warm-up’ on leg day. It takes me 20-30 minutes depending on how much time I have. I simply throw some sprints into my treadmill warm-up, picking up the speed with each work period. When I reach my peak I’m running at a pace that I can really only keep up for about one minute, before my legs, heart, and lungs tell me to stop. On days when I’m focusing on my upper body my warm up is less intense, but that’s just my personal preference.

So, at the end of the day, HIIT is a great method for improving your fitness, shaving time off your race PR’s and can be done in less time than a 5-mile run. But, too much of a good thing can be, well, too much, especially if you’re new to exercising and don’t have the same work capacity of someone more advanced.

If you’re a beginner and want to try some interval training, that’s great! These types of workouts can be modified for all fitness levels. You might find that you are unable to get your heart rate up very high before it feels uncomfortable. If that’s the case, use the talk test to gauge how hard you are working. During your rest periods you should be able to have a conversation. During your work periods you should be breathing hard enough that talking is more difficult. Work just slightly above your comfort zone. Your rest periods should be at least as long as your work periods, but take all the time you need in between intervals to feel recovered. As you get more fit you’ll be more comfortable working harder. In total, the workout should take you 20-30 minutes. Remember, always work out at the fitness level you’re at, not the level you WANT to be at!

If you’re a more experienced exerciser, try to keep your work intervals to under 2 minutes, and focus on increasing the intensity of your intervals within that time frame. Your rest breaks should also be at least the same length as your work periods. The more intense the interval, the longer recovery period you’ll need. Each interval should feel as good as the one before it. If you’re losing steam and can’t keep the same pace, increase the recovery period for the next interval. It’s about having good quality intervals, not a bunch of half-assed ones. In total, the workout should still take you 20-30 minutes.

Happy Training Everyone!

Questions? Comments? Want to start training but don’t know where to begin? Contact me today!

*If you are not currently exercising, or have health concerns always check with your doctor before starting a fitness program*