The Fundamentals of HIIT Training
The idea of “intervals” in high intensity interval training (HIIT) comes from the fact that we are oscillatory beings: we need periods of intensity followed by periods of rest.
Yesterday I took a class at Switch Playground, a fitness experience that bills itself as a HIIT workout. Except there was no recovery time built in. It was a HIT class: high-intensity training without intervals.
Every 30 seconds we switched exercises. Every two minutes we switched stations.
The entire class was intense, from the opening yoga flow that went straight into chaturanga to the 60-seconds of stretching at the end. Breaks were just long enough to move to the next station.
The hour was packed full with activity, but wasn’t very productive. And by “productive” I mean that it wasn’t effective in reaching an outcome. Unless that outcome was to sweat a lot.
By the end of the class I was exhausted, but not because I worked my muscles to their limits. My fatigue was in my head; my mental energy was drained from the constant switching of exercises.
In fact, my body still had more to give. This was evidenced by the fact that I was able to reenergize for trampoline class within the hour.
Busy-ness and Multi-Tasking
Life is about patterns, and this is the dominant pattern in our culture, reflected in everything from fitness classes to work to how we schedule leisure time for ourselves and our kids (if you have kids). The accepted norm is to pack your day with many activities, many “stations,” and minimal recovery time.
Busy has become a badge of honor. Employers seek applicants who have proven their mastery in the “skill” of “multi-tasking.”
The problem with this is that it’s not aligned with how our systems are meant to work.
Multi-tasking is a myth. From the perspective of the brain, multi-tasking doesn’t even exist. It is simply very quick task-switching. Studies show that each time you shift your focus, it takes more time to recover and get back on track.
The premium on busy and multi-tasking leaves many people swimming in shallow work.
It’s the opposite of what Cal Newport calls Deep Work — focused periods that allow us to immerse in our work to produce real value.
Shallow work is the work equivalent of empty calories: you feel full in the moment, but you’re hungry again in an hour.
The Switch Playground class was the fitness version of shallow work.
When you engage in shallow work, you feel like you got a lot done, and you’re tired at the end of the day, but you didn’t really make progress on what matters.
Constant task-switching prevents you from immersing in the work for long enough to make meaningful progress. Each time you return, you have to get back up to speed on where you were.
This behavior is fueled by the belief that our productivity is measured by how much we can pack into an hour, a day, or a week. We live in a culture that prizes “getting things done” over creating sustainable results.
The dominant view is that if you’re not sweating or hustling, you’re not working hard enough.
The constant switching from one thing to the next, without any time to settle in or immerse, drains our mental energy and puts our bodies in constant fight-or-flight mode. The result is that we live in a constant state of stress. We don’t slow down, let alone stop.
The Stress Addiction
Here’s the problem: even if you know this, it’s hard to break the cycle.
This pattern of behavior is addictive.
What’s really happening when we overpack our lives is that we put our bodies into stress response. Our bodies produce adrenaline and other hormones, which are highly addictive.
Like most addictive substances, these stress hormones can feel energizing in the short term. Over time, however, they create toxins that build up within us.
As Tony Schwartz and Jim Loehr explain in The Power of Full Engagement, these toxins produce emotional symptoms including hyperactivity, aggressiveness, impatience, irritability, anger, self-absorption, and insensitivity to others. They also lead to physical symptoms like headaches, back pain, migraines, and gastrointestinal disorders. The toxins drain our mental focus, deplete our attention and eventually leave us feeling disconnected from our purpose.
Not quite the recipe for productivity.
And yet instead of stopping to recover or changing our patterns to focus more on deep work, we continue the pattern of shallow work and busyness. We ramp up the intensity when we should be paring it down. We fall in line with the command to hustle and work harder.
The body will find a way to get the rest and recovery it needs. Eventually, we stop only when we are sidelined by injury, illness, or burnout, if not death.
The Cycle of Growth
It’s important to understand that stress, in itself, is not “bad.”
In the body, we grow a muscle by using stress, in the form of weights, to break down the muscles. But the muscles grow during the rest and recovery phase. The same process applies to our mental, emotional, and spiritual systems.
Without rest, we get only the breakdown in our bodies, minds, and spirits, but not the benefits of growth.
We may check a lot of boxes and “get things done,” but we don’t create anything of substance.
Slowing down, resting, and engaging in recovery are not the opposite of “hard work.” They are essential to the process. Without the rest phase, you will sweat a lot, but you won’t see progress.