We have all experienced a feeling of ‘the walls closing in’ during 2020.

It may be stress. It may be fear. It may be solitude.

The unmistakable trend we have seen in clinic since re-opening in June is a substantial uptick in people reporting feelings of anxiety, panic disorders, and depressive symptomatology.

I’m certain waiting lists for mental health professionals are at an all time high.

Layer on top of that the closing of most gyms across Ontario and folks that typically use exercise as an outlet are really struggling.

We’ve been coaching people to get outside (safely). Exercise does not require a gym.

For years research has shown efficacy of physical activity on the effects of anxiety disorders. Typically aerobic exercise is the intervention studied. I can think of dozens of folks we see who manage their stress and anxiety with cardio.

So I got to thinking…..what is THE BEST type of exercise for anxiety?

If we knew this answer, we could pass a simple message on to our clients to help manage their stress through what is promising to be a long winter.

Past research has shown that aerobic exercise has a medium effect on General Anxiety Disorder (GAD), social anxiety disorder, panic disorders, and specific phobias. In fact, there has been so much research that recently it has been summarized in meta-analyses, which have shown that the effects are repeatable and robust.

That said, they almost always focus on one specific type of exercise…..low to moderate intensity cardio. A moderate cardio routine would be up to 70% of one’s maximal heart rate for 30 minute sessions.

Now as we would all expect, the anti-anxiety effects of this type of moderate intensity exercise are shown as superior when compared to a control group that does not exercise.

Yet an under appreciated, but just as interesting finding is that in the studies that also include a lower physical strain subgroup, the moderate exercise group has better outcomes against anxiety symptoms!

In fact a recent meta analysis showed that ‘higher intensity’ was superior to ‘low intensity exercise’ for reducing disorder specific anxiety with at least a small effect size.

Eureka!!

A research group decided to take this one step further. They decided to look at even higher intensity exercise as an intervention in the form of HIIT (High Intensity Interval Training) and evaluate the effects on General Anxiety Disorders. The study was published just this month in The Journal of Anxiety Disorders.

HIIT training has previously been shown to be better then moderate intensity exercise on depressive symptoms.

Despite this, HIIT training has never been studied for anxiety.

The current study was from Germany and enrolled 33 patients with General Anxiety Disorder. The patients could be taking pharmaceuticals for their anxiety provided the dose was stable for at least 4 weeks prior to the beginning of the trial and through the study period. They were randomized to either a HIIT group or a low intensity training group.

The HIIT group performed exercise every second day for just 12 days using a cycle ergometer (essentially a stationary bike) and did 20 minutes with alternating bouts of 60 seconds ‘on’ at 77-95% of their maximal heart rate, and then 60 seconds ‘off’ at 70% or below.

The control group just did low level aerobic exercise, never going above 70% of their maximal heart rate.

Prior to the study, both groups scored as ‘high worriers’ on a scale called the PSWQ-D that measures a person’s amount of worry. After the exercise intervention, both the HIIT group and low intensity group saw a reduction in worrying, however it was significantly larger in the HIIT group.

On other anxiety symptoms there was a medium decrease in symptom severity in the HIIT group, but no difference in the Low Intensity group. This included a stronger reduction in unspecific anxiety and depression where there was a medium to very large effect seen on all clinical measures in the HIIT group.

One of the key improvements was in an individuals perceived control over their symptoms. This was absent in the lower intensity group. Somehow the higher intensity seems to trigger a sense of control over one’s feelings of anxiety that is just not there with low levels of exercise.

One very interesting finding is that the impact on symptoms with was already taking place DURING THE INTERVENTION. That means as soon as they started a 12 day exercise intervention the people already felt better. The effect was still there 18 days after the end of the active period, when people were no longer exercising. That means the effects were near immediate and they were lasting (at least in the short term).

This was such an important finding that the authors commented that medication and psychotherapy achieve small and medium to large effects within several weeks or months in General Anxiety Disorder. Yet HIIT training showed not only a comparable, or even higher efficacy specific to anxiety, but it was with a substantially faster onset of action then medication and psychotherapy.

Another important finding is that the HIIT training was VERY well tolerated. A 2019 study showed that HIIT training is well tolerated even with people that are previously sedentary. In this study, there was no difference in adherence between the HIIT exercise group and the low intensity group. When compared to other forms of therapy, the HIIT group had a substantially lower cancellation rate compared to CBT and antidepressants which see a cancellation rate of up to 24% for anxiety disorders.

An important message that should not be lost in all of these unbelievable findings is that the low intensity training group also had a significant impact on worrying, unspecific anxiety and depression. Any form of exercise is way better then not exercising. By no means are we saying if you can’t do HIIT training then it is not worth it.

That said, this study seems to suggest the best way to ‘work out your worries’ is with some intensity.

Need help designing a simple HIIT program? Just ask any of us the next time you are in. We love to help.