It’s probably no surprise to you that exercise, nutrition, and caffeine can have a significant impact on your brain health. You’ve probably read many articles giving you advice on how they can help your mind. You might even have adopted a habit or two.
But while certain practices seem productive in theory, they’re more likely to hamper your brain function rather than boost it. Here are 5 of those common habits, and what you can do instead:
Urban jogging or city cycling
Whenever I see joggers on city pavements, I want to stop them and tell them to stay away from the roadside and head to the gym. This is because although cardiovascular exercise is a great way to boost alertness, mood, and learning, inhaling polluted air means you may cancel out much of the benefit. Particulate matter from car exhaust is terrible for the brain–it can lead to neuroinflammation and cognitive decline.
When you inhale polluted air, it reduces levels of BDNF in the brain. BDNF is a protein that enhances brain plasticity–which improves cognition and memory performance. One study looked at BDNF levels among cyclists who rode in heavy traffic and found that the exercise led to no increase in BDNF at all.
The best alternative for urban dwellers is to head to an indoor gym–but if you don’t want to give up your outdoor run, download an air-quality app and check your route before a ride or a run. There are lots to choose from, including Air Matters, Air Visual App, and Breezometer. You can also just avoid major roads altogether, and jog on woodland trails or in park interiors instead, away from traffic and fumes.
Grazing on “healthy” food
We have become habitual grazers. People in the U.S. consume 25% of calories in snack form and rarely go for more than a few hours without something to eat. Our parents’ generation believed in the importance of working up an appetite and were cautious about “spoiling” dinner by overdoing the snacks, but we fill our work bags with nuts, fruit, and protein shakes, like explorers off on a hike.
The science on satiation and brain function is contradictory. Yes, extreme hunger can negatively impact concentration, mood, and unconscious bias, but if you’ve maintained a healthy balanced diet for some time, practicing intermittent fasting can help you build mental resilience. Look at it as a form of stress-inoculation, where you learn to withstand hunger and manage your own recovery.
We all tend to overestimate the healthiness of our diets–so in addition to fasting, you can also benefit from noting down everything that passes your lips. Keep a note too of your mental energy throughout the day, and take a look at the relationship between the two.
It’s easy to assume that if you build up a sleep deficit during a period of burning the candle, you can catch up with a few strategic lie-ins. But messing with your wake-up time can have a negative impact on your circadian rhythm. A study by researchers at University of Arizona in Tucson found that “social jet lag”–losing sleep and sleeping and waking at random times–can lead to poor mood and fatigue.
Aim to sleep 7 to 9 hours per night plus nap for a full sleep cycle a few days a week. If you have to take a nap, make sure not to do it later in the day–that can disrupt your sleep. Be mindful of how long your naps are too. Short naps (20-40 minutes) can make you feel groggy. However, if you can manage to get 90 minutes of sleep (equivalent to a full sleep-cycle), your brain moves through all the different phases of sleep–including the most restorative NREM or stage 3 “dreamless” sleep– your mind gets a chance to embed new learning and memories, and make new connections that lead to creative insights.
Cutting caffeine completely
From a thorough assessment of the evidence, I’m convinced that when it comes to caffeine, for most people, little is probably better than none. I’d particularly advise against a radical change in your habits, like going cold turkey if you’re a four- or five-a-day drinker, for example. Moderate caffeine can yield health benefits. It’s a potent source of antioxidants, and it stimulates the nervous system, which makes you alert. It also sharpens your memory, and researchers at Johns Hopkins University found that it can improve long-term memory recall.
Ideally, opt for no more than a cup or two a day, and time them to deliver the maximum brain benefit. Drink it in the morning, and after lunch (but not after 2 p.m., to avoid the long half-life keeping you up at night!). Remember, the alertness boost is most intense for the first 45 minutes after you drink it.
Although exercise is undoubtedly good for your brain, timing is essential. Intensive training too close to bedtime can interfere with sleep, although this isn’t universal. In general, the evidence shows that those who exercise at any time of day sleep better than those who are inactive.
If you can fit it in, it’s best to exercise early in the morning, as we are 15% more productive on days where we do 30 minutes of aerobic exercise in the morning. And who doesn’t want that? Whenever you do work out, make sure you refuel with protein and rehydrate with plenty of water. Otherwise, the effects of muscle repair and dehydration will negatively impact on your body and brain function.
When it comes to our health, we don’t always think about nurturing our brains the way we nourish our bodies. But to be our most productive self, that’s precisely what we need to do. Start by adopting one or two of these alternatives. Your mind will thank you.
Dr. Tara Swart is a neuroscientist, leadership coach, author, and medical doctor. Follow her on Twitter at @TaraSwart. She is the author of the upcoming book, The Source: Open Your Mind, Change Your Life.