Speaking at the Australian Corporate Lawyers Association (ACLA) Corporate Counsel Day held in Brisbane on 8 March, McDonald said lawyers must get moving if they want to get the most out of their cognitive functions, cope with stress and reduce the effects of mental illness.

“When you’re fit, everything feels a little bit easier,” he said. “It’s thriving instead of just surviving. Sometimes you need to know that exercise is going to directly influence your work performance. If you’re fit, you’ll definitely give yourself a better shot.”

McDonald said the most important part of a lawyer’s brain is the hippocampus, which controls executive function and allows us to focus on and comprehend ideas; think laterally; manage emotions; and use rationale and working memory.

He said that recent studies have shown direct links between regular exercise and an improvement in a person’s executive function.

“Exercise releases ‘brain fertilizer’ from our muscles,” he said. “It enters the brain tissue and targets the hippocampus. Of all the areas of the brain to benefit, the hippocampus is that area, which is pretty exciting.”

McDonald said lawyers already have an advantage in that they exercise their brain on a daily basis, so adding exercise to the mix can have fantastic results for cognitive function.

“I call it the ‘lawyer advantage’, because you are training that part of your brain,” he said. “You need fertilizer, but you also need the plant. Whenever you use your brain, you provide the sun for brain cells … It provides direction for those nerve cells to grow. So the seeds are there; you just need to provide fertilizer.”

This “fertilizer” is also essential if lawyers – who suffer from the highest rates of depression and anxiety of any profession – are to stay mentally healthy.

“Exercise controls blood sugar better than anything else. It builds resilience in brain cells so they don’t respond as acutely to stress,” said McDonald. “Your emotional stability is better and you can handle high stress. It’s an immunization to stress.”

McDonald said lawyers should aim to exercise, at moderate intensity, for at least 30 minutes, three times a week, and said it will have both short and long-term benefits.

“The survival muscle has changed,” he said. “If you can keep your brain active, and with a high level of function, then you’ll be able to put in your best performance. There is a big difference between surviving work and feeling good all week long.”