Updated: Apr 7, 2020
According to the World Health Organisation, 50% of women and 40% of men in Europe and the USA are insufficiently active. One of the doctors I follow, Dr Chatterjee, has stated that in Manchester alone around half a million pounds a week of NHS funding goes towards conditions related to inactivity.
The benefits of exercise go far beyond just physical improvements. Research is now looking into exercise and its effect on our brains, not only in terms of decreasing stress but also in terms of helping prevent the likelihood of depression and even Alzheimer’s.
So here’s a list of my top, most exciting research findings on how exercise may affect the brain:
Mild to moderate intensity exercise, such as a short walk, can decrease cortisol (our stress hormone) to buffer our stress levels throughout the day.
Exercise (even for 8-12 weeks) has been shown to increase the production of BDNF (brain-derived neurotrophic factor) which increases the size of our hippocampus, a part of the brain responsible for memory and learning.
Two 10-15 minute HIIT (high intensity interval training) sessions per week has been shown to decrease aging at a cellular level and increase brain cells (Mayo Clinic, 2017). One study brought in three walks per week and found a decreased physiological brain age in subjects, with scores decreasing from 72 years old to 68 years old in psychological tests.
Walking prior to a task has been shown to help us create twice as many new ideas. This was shown to be irrelevant of age, so people in their 70’s who walked prior to a creative task will generate twice as many new ideas as a sedentary 20 year old attempting a task without walking before.
A large randomised controlled trial (of 900 people, followed over 12 months in 2016) compared CBT (cognitive behavioural therapy) and exercise and found comparable results in treating depression (both were effective).
Doing the recommended government guideline of 30 minutes exercise 5 times per week showed a 30% decreased odds of developing depression (comparison of 46 studies, 26,000 people, over 7 ½ years). Another study of 100,000 people found that, even in those who are genetically predisposed, exercise can reduce the risk of depression.
Exercise has been shown to decrease anxiety in some studies.
Exercise has also been shown to decrease inflammation in our bodies. There is emerging research on the link between inflammation and depression. One study found that those with higher levels of inflammation were less likely to respond to anti-depressant drugs.
Regular walking and strength training have been shown to help prevent Alzheimer’s.
How about the other benefits of exercise on the body:
Improves immune function by increasing natural killer cell activity.
Improves ability to make energy by improving mitochondrial biogenesis.
Improves blood pressure and circulatory/lymphatic flow, decreases heart attacks and strokes.
Changes the composition of our gut microbiome.
Decreases the risk of type 2 diabetes and cancer.
Decreases the risk of osteoporosis (strength training in particular).
Decreases visceral fat (fat stored around our internal organs) and aids weight loss.
Helps regulate hormone function.
Overall, the benefits of exercise on so many bodily functions are fascinating. BDNF (brain-derived neurotrophic factor) can literally increase the amount of brain cells and connections! There is no drug that can replicate these effects!
So exercise is clearly important. But does an hour gym session after sitting still at an office chair all day have the same effect as getting up and moving regularly through the day? A study in 2017 showed that breaking up sitting with light activity throughout the day had much greater improvements than just one exercise session after work (especially in glucose levels/insulin sensitivity in those with type 2 diabetes). That’s definitely not to say don’t do an hour workout before or after work… just try and move around a bit during the day as well!
NHS guidelines recommend 150 minutes of moderate intensity exercise per week (or 75 minutes of vigorous activity per week). Moderate intensity exercise is classed as a level at which you can just about hold a conversation. Vigorous exercise is classed as a level at which you are panting and can’t hold a conversation!
My best tips would be to find something that you enjoy, whether that’s walking outdoors, dancing around the house to a few upbeat tracks that get your heart rate up each day or lifting weights at the gym. There’s so much variety out there and it’s all about finding what works for you and what fits in to your lifestyle. Why not even just start with trying to hit 10,000 steps a day (most phones or smart watches will monitor this nowadays)?
One thing I would also add is that variety of exercise is also great within your own week. How about doing one form of aerobic and/or high intensity exercise, one form of resistance training and one form of flexibility based work (like yoga)? Personally I split my week into: Netball (aerobic/high intensity exercise), gym sessions (resistance based exercise and yoga/stretching at the end) and indoor climbing (a newer, fun challenge I’ve got in to recently!).
For more information:
Read ‘The Four Pillar Plan’ by Dr Rangan Chatterjee
Listen to the ‘Feel Better, Live More’ podcast by Dr Rangan Chatterjee and various guests, numbers 46, 90 and 97 (where most of my statistics have come from).