By: Colin Bullen

This is part of The BRATLAB ‘Behavioral Prescription’ Series

It may be hard to admit, but COVID-19 is going to be a problem for a while.  To stabilize the spread of the disease to levels manageable within the US (or any) health system, we will need what’s known as ‘herd immunity’. Herd immunity is defined as “a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through previous infections or vaccination, thereby providing a measure of protection for individuals who are not immune.”[1] (see fig.1).

Crowd Immunity

Although suggested required levels of infections for herd immunity to occur vary, studies of past epidemics lead us to conclude that somewhere between 50% and 90% of the population must be infected and recovered before community immunity sets in[2]. As this is a highly infectious disease, similar to measles, the level of herd immunity required to moderate the spread of COVID-19 to stable levels is likely to be towards the upper-bound of that range – measles herd immunity occurs at 90% immunized levels.

With the vaccine unlikely until well into 2021, we’re looking at a lot of people getting infected before things can get back to ‘normal’, or more likely a new normal.

The Virus Is Not the Only Problem

To save human lives by managing the strain on the health systems, governments have had to put countries into ‘lockdown’. This means that as contact between human beings is stopped, the virus spread is significantly slowed or stopped.  From a virus control point of view, this makes absolute sense. However, the impact on human beings of isolation is problematic.

On March 27, Hans Kluge, the European Director of WHO, noted “Isolation, physical distancing, the closure of schools and workplaces are challenges that affect us, and it is natural to feel stress, anxiety, fear and loneliness at this time”[3]. A 2019 study led by Kassandra Alcaraz, PhD[4] suggests that “social isolation was associated with (an increase in) all-cause mortality in all subgroups” by gender and race. The American Psychological Association[5] notes “Loneliness, it seems, can lead to long-term “fight-or-flight” stress signaling, which negatively affects immune system functioning. Simply put, people who feel lonely have less immunity and more inflammation than people who don’t.” Ironically, keeping us apart negatively impacts our immune systems at a time when we need them to be strong.

Behaviors That Lower Your Stress, Anxiety and Help Manage Depression During Lockdown

As the impact of lost jobs, business failures, and financial ruin are added to the load of people grieving for those who have passed prematurely, charities and paid professionals in the psychological care space are being overloaded by requests for help. In the light of emergencies like this, it’s very easy to panic, but there are simple things we can do to stay mentally healthy.

Helpfully, keeping physically fit is the best way to stay mentally fit. The Behavioral Research and Applied Technology Laboratory research suggests that among a wide range of behavioral changes that can reduce stress, anxiety and depression, exercise stands out as the most effective. Research indicates that exercise, in the form of 30 minutes of moderate-intensity activity taken five days per week, can reduce anxiety by 65% and depression by 50%[6].

Curiously enough, the second most powerful impact on mental health is healthy eating. As always, the prescription of healthy eating is difficult to dissect, but there are strong associations between a healthy diet containing the right level of nutrients such as omega-3 fatty acids, zinc, folates and magnesium and reduced levels of anxiety and depression. Research suggests that a diet rich in these nutrients while avoiding inflammatory food such as processed food and excess salt and sugar can lower rates of depression by as much as 50%.

Methods to Manage Those Pesky Temptations

When we enter unfamiliar circumstances and old routines are discarded, it’s natural to take the easy options. “So, the gym’s shutdown and I have to socially isolate? How can I exercise in these circumstances? I’ll just take a few weeks off.” There will be a tendency for people to reach for the easy-option convenience food when they can get to the shops. Nothing could be easier right now than to slip into bad habits regarding eating and exercise, and nothing could be worse for your mental health.

It takes careful planning to set up your new environment to influence you to do the right things, and not be tempted by bad habits.

It’s time to help yourself, and help those around you, by setting up the contexts of your lives to influence the right behavior. You could tune into a virtual exercise routine provider like John Godoy or any of the many hundreds that are out there. Before you set off to the store, write the list of things you need to ensure that you’re eating healthy, and don’t be tempted to walk down the convenience food aisle! Reward yourself if you achieve that goal with a healthy treat.

If you want to know more about how to set up your new environments for healthy influence, to make it easier to adopt the healthy options, consider taking our training course ‘Become a Change Agent’ – available at a discount to NWI members.

Stay safe and stay well. If you have thoughts on this article, please contact us at

Colin BullenColin Bullen is the founder and director of Change Craft, a global business established to help organisations execute effective and successful well-being change. In business, he’s the technician, evaluator, and strategist. A true road-less-traveled devotee, he qualified as an actuary in 1992 in the UK before spending 13 years in South Africa where he met Chicago-based business partner Hanlie van Wyk. During this time, he has steadily broadened his métier into health, well-being, leadership, strategy, assessment, and data.

Colin has a deep passion for helping companies find their human touch, whilst accelerating their performance and focusing their vision. Colin is also one of the creators of the behavioral research database that is BRATLAB and has been a driving force behind early successes in Change Craft.








[6] Osei-Tutu, K.B. and Campagna, P.D. (2005). The effects of short- vs. long-bout exercise on mood, VO2max., and percent body fat. Preventive Medicine 40: 92–98