HIIT, an acronymic for High Intensity Interval Training, has been around for decades, it is at an all-time peak of popularity. And for good reason, it’s the best way for the vast majority of people to exercise. It’s time efficient and works. Boutique fitness facilities, globo gyms, and everything in between have popped up on every corner, each with “their” own style of HIIT. In CrossFit, we typically call this portion of our training “conditioning.”
You might feel like you are getting an incredible workout as you are drenched with sweat and tired. For most, this will yield initial results. Unfortunately, some problems can arise in these workouts that can lead to a plateau because of lack of variety in duration, light loads, and doing too many movements in one class.
Lack of Variety in Duration
When you are only training in one energy system, such as a consistent pace for 30 minutes to an hour, you are only training the body metabolically one way. Your energy systems and body easily adapt to this time frame and intensity, thus becoming super-efficient. If we are looking for changes in our fitness or body composition, this isn’t a good – it means less calories burned, adapted muscles, and fewer results.
The Solution: ensure your workouts vary in duration and intensity. Some workouts should be at a moderate heart rate (50-70%) for long durations (30 minutes to an hour). Other workouts however should be short and extremely intense (working at 90%+ for 3-8 minutes) and others with moderate duration and intensity (70-90% effort and 8-25 minutes in length).
The Catch: A three-minute workout should completely suck. If you aren’t giving an all-out effort, your results are going to be extremely subpar.
Not enough load to make muscular change
Muscles need to be loaded to make change. Light weight for huge volumes don’t always cut it. The body needs to be challenged via relatively high loads. Muscles should be tired after a workout and need recovery in order to make change. Strength specific days are also vital to get stronger and improve muscular definition. This will enable you to burn more calories daily, prevent muscle land bone density loss over time, and improve physique.
The Solution: Challenge yourself not only via repetitions, but also through load. Sore muscles aren’t necessary after every workout, but if you are never sore, the muscles probably aren’t making any change.
The Catch: Gradually increase the load over time and don’t always stick to the same weights. If you’ve been swinging a 25-lb KB for 6 months now, it might be time to step it up to the next weight.
Too little purposeful movements, too many fillers
In order to make change, we need quality over quantity. Too often we see HIIT classes with tons of movements and lack of emphasis on a certain lift, muscle group, or metabolic demand. You can’t do everything in an hour workout, results come through the process of exercising, not one workout. Focus needs to be achieved on particular movements, muscular recruitment, and energy systems. Moving from station to station often forces the coach to throw exercises in there, trying to do too much in one workout to be able to see long term results. Full body workouts are great, but shouldn’t be happening daily.
The Solution: Most workouts should be focusing on 1-3 movements/body parts and one energy system.
The Catch: One hard workout a week doesn’t get you results. You need to be consistent with your exercise.
Hormonal Stress on the Body
As with any exercise program, how our body responds to the increase in physical stress is vital. We need to be considerate of the load the endocrine system is taking. The body responds to mental and physical stress in the same way – an increase in the catabolic hormone cortisol. This fight or flight hormone elevates when we are stressed and tells the body to preserve fat and not build muscle. Ancestrally, it helped us conserve as we ran from predators. Currently, it blocks out ability to burn fat and build lean muscle.
Your exercise program needs to ensure that you are recovering properly to keep cortisol levels low. Too many 60-minute interval classes per week put a huge level of unwanted stress on the body.
The Solution: Have variety in your workouts, especially in length, intensity, and load. Some days should be long while others quick. Some will focus on high heart rate and others on low heart rate. And some days should be hard and others easy.
The Catch: For most individual’s goals, 2-4 strength biased (weightlifting low heart rate and rest) workouts and 2-4 conditioning biased (HIIT) workouts per week are all they need.
Below is a typical 5 Day (Monday-Friday) Schedule at Aspire, featuring two strength bias days and 3 conditioning biased days, in addition to an array of physical and metabolic demands.
Monday – Strength + 12-minute conditioning
Tuesday – 20-minute conditioning
Wednesday – Strength + 16-minute conditioning
Thursday – 8-minute conditioning
Friday – 25-minute conditioning
In closing, don’t get fooled by the “more is vital” approach when it comes to your HIIT training. It often leads to quick results, then the body plateaus as it adjusts to the duration, light loads, and filler movements as it creates a huge hormonal load on the body. Fix these issues, pay attention to your body and its progress, and you’ll be on your road to results once again.
Sean Spire is the Owner and Head Coach of Aspire. Athletically, he enjoys lifting heavy shit, running in the middle of the day, and tough MetCons. Personally, he likes spending time with his amazing wife, Erika, and dog, Reef.