Blue Monday: How to boost your mood when you're running on empty

How energetic we feel at any one time is affected by many things. Photo / 123RF

It's early January and like everyone else, I'm shattered. Two cups of tea have barely made a dent in my morning malaise, so I'm forcing down a fizzy ginseng, guarana and green tea drink that promises a "natural boost" to help me make it through the day. Now I feel sick and tired.

The quest for more energy, more zest, more vim and vigour sustains a multimillion-pound wellness industry, which thrives on selling the promise of boundless energy to the worried well. Most of it is anything but evidence-based, and after a tough couple of years and with no immediate end to the pandemic in sight, now seems like a good time to seek out energy-boosting strategies that actually work.

Like so many things in science, there are no simple answers. How energetic we feel at any one time is affected by many things – some physical, such as sleep, diet and whether we are fighting off a cold or other infection, and others, such as motivation, which are more psychological. Caffeine, many people's go-to for a boost, works across both levels, cheating the brain by blocking a sleep-promoting chemical to provide a mood boost and dose of alertness when we would otherwise be nodding off.

Chemical cheats aside, the obvious place to start with any attempt to boost energy is in the metabolism: the process by which chemical energy is harnessed from our food and used to power everything from the basic functions of our cells to our every movement and thought. This happens in the mitochondria, which as anyone who did biology at school will know, are the "powerhouses of the cells", creating ATP, the chemical that powers everything our cells do.

We don't fully understand how the workings of our mitochondria affect how energetic we feel, but we do know that people who have rare disorders of the mitochondria feel pretty lousy. "Tiredness and fatigue is their number one symptom," says Martin Picard, who studies the links between mitochondria and mood at the University of Columbia in New York. Mitochondria problems have also been seen in people with depression and chronic fatigue.

Which suggests that we can feel it when our bodies are running on empty. Even so, boosting your energy levels can't be as simple as just adding more fuel to the furnace, says Herman Pontzer, who studies energetics and metabolism at Duke University in North Carolina and is the author of Burn: The Misunderstood Science of Metabolism. "If you're starving you're likely to feel lethargic, but it's definitely not the case that eating more calories or having a faster metabolism means you'll feel more energetic," he says. "If it were like that, people with obesity would be the most energetic. I don't think that's the case."

Picard agrees, and also points out that there are signs that too much fuel actually backfires, making us feel worse. "If you overfeed people you would think – oh, more energy, they are going to feel better. But no, it actually taxes the body… physiologically the body becomes less efficient," he says. So, strangely, less fuel may equal more power. In particular, avoiding refined sugars, which studies suggest disrupt the mitochondria, making them less efficient. "Not eating too much is probably the best, most concrete thing we know that can promote mitochondrial health at this point," says Picard.

Another is reducing stress. Picard's research shows that the stress response puts a huge strain on our mitochondria, which not only need to provide energy for the raised heart rate and other physical responses to stress, but also produce and pump out the stress hormones that keep the response going. For reasons that aren't fully understood, stress makes cells age faster, perhaps because they are being forced to work harder than they should.

Nevertheless, Pontzer remains unconvinced that "boosting" the activity of our mitochondria to get more energy out of them is possible. His research suggests that our bodies adjust the rate at which the mitochondria burn calories to keep the total within a narrow range. If we exercise more, for example, the body adjusts the overall metabolic rate to spend less energy on other things, such as the stress response or inflammation. So, any attempt to tinker with your mitochondria is likely to be pointless, and "wouldn't necessarily increase vitality", says Pontzer.

So, what is vitality if not the feeling of supercharged mitochondria? Part of the answer may come down to mindset. Psychologists used to believe that mental energy was a limited resource: that we run it down by working hard – physically or mentally – and that this leaves us feeling depleted. More recent research, however, suggests that this is only true if you think it is. People who considered work to be energising had the reverse effect: they felt boosted, not depleted, by their efforts. This, of course, depends what it is that you are doing – it's easier to feel energised when the work you are doing has meaning, less so when it's a tedious means to an end.

There is good news, however, for anyone who blames their low energy levels on simply getting old. Research by Brian Cardini at the University of Zurich suggests that while it is true that older people run out of perceived energy more quickly, they also recharge more quickly than younger folk. Which suggests that taking regular rests (naps, even) to recharge could be the secret to increased staying power overall.

It goes without saying that, nap or no nap, getting the recommended seven to nine hours a night is a good idea for anyone who feels depleted. As is turning off screens or wearing blue light-blocking glasses in the evening. Studies have shown that two hours of screen time in the evening blocks the hormone melatonin, which is needed for good quality sleep. When bright light hits our eyes, especially at the blue end of the spectrum, it stimulates a part of the brain called the suprachiasmatic nucleus, which controls not only the sleep/wake cycle of but also alertness throughout the day.

So while too much light close to bedtime will scupper sleep, during the day it could be the key to more energy. "Light affects areas of the brain controlling alertness directly – it literally wakes us up," says Linda Geddes, author of Chasing the Sun: The New Science of Sunlight and How it Shapes Our Bodies and Minds.

Studies suggest that an hour of exposure to blue-spectrum light boosted people's reaction time by more than if they had consumed two cups of coffee, says Geddes. She suggests getting outdoors little and often throughout the day, or using a Seasonal Affective Disorder light "to provide an extra energy shot" in the winter.

Of all the way to get more energy, though, exercise tops the list. It stimulates the suprachiasmatic nucleus, helping us to feel more alert, floods the brain with feel-good chemicals to boost motivation and reduce stress while also encouraging the production of new mitochondria in the muscles.

So, forget the fancy supplements. If there's one weird trick that actually works to provide more energy you can feel, exercise is it: especially when done outside on a bright day. If that sounds too exhausting, maybe start with a nice, restorative nap.