Doctors have warned that Ugandans balancing late-night commitments for work, study, or family may harm their physical health, mental focus, and emotional well-being, urging them to reset their body clocks for better sleep quality.
Doctors say irregular bedtimes, sleeping in on weekends, and exposure to bright screens at night can disrupt the body’s circadian rhythm, the roughly 24-hour cycle that regulates sleep and wakefulness.
At about 5pm, the day is far from over for several Ugandans, with some workers moving from their main jobs to side businesses, evening shifts, and other income-generating activities, with the growing pressure to earn extra income.
Others use the evening to tutor, study, and complete housework. By the time they finish, it may be close to midnight or later, yet the following morning often comes early.
Dr Justus Atuhaire, a physician at Mulago National Referral Hospital, says: ‘The circadian rhythm is a natural physical and mental loop that runs on an approximately 24-hour cycle that tells the body when it is time to feel awake and alert, and when it is time to feel sleepy.’
The body clock also influences body temperature, digestion, and hormone levels, with light and darkness serving as major signals that regulate the cycle.
When the clock gets out of step
Daylight tells the brain that it is daytime, while darkness promotes the release of melatonin, a hormone associated with preparing the body for sleep. Bright artificial light late in the evening can interfere with this process and make it harder to fall asleep.
‘Late-night work, device screens, tasks, and problem-solving keep your brain alert and active when it should be winding down. People who use strong lights at night delay natural sleep since they stop your body from sensing true darkness,’ Dr Atuhaire explains.
Constantly changing sleep times can also prevent the body from settling into a predictable rhythm.
‘Shifting your schedule constantly forces your internal clock to reset every single day, which prevents the body from ever locking into a healthy, predictable pattern. It removes the predictable cues your body relies on,’ he adds.
Dr Joel Mirembe Nsubuga, a physician and former secretary general of the Uganda Medical Association, says an occasional short night should not become a routine.
‘If you have had a short night, you can use measures such as a brief nap to temporarily improve your alertness, but you still need to recover the lost sleep. The National Institutes of Health (NIH) recommends that adults keep naps to about 20 minutes to avoid feeling groggy.’
Resetting the body clock
The National Heart, Lung and Blood Institute recommends going to bed and waking up at the same time each day, including weekends, because sleeping in can disrupt the body’s sleep-wake rhythm.
‘The human body clock generally takes one day per hour of time shift to fully adjust. When adjusting your sleep schedule, shifting your bedtime back gradually is highly recommended over trying to change it all at once,’ Dr Mirembe says.
He recommends moving bedtime and wake-up time by 15 to 30 minutes every two to three days. ‘If your current bedtime is 1am, aim for 12.45am for a couple of nights, then 12.30am and so on. Progress is gradual, so holding your new times steady on weekends is what makes the change stick.’
Dr Atuhaire recommends exposure to daylight during the day, saying light is one of the body’s strongest signals for regulating the sleep-wake cycle.
‘The body’s internal clock, or circadian rhythm, responds strongly to light. Exposure to daylight during the day helps regulate the sleep-wake cycle and can promote alertness,’ he says.
At night, Mr Davis Amanya, a wellness coach, advises people to reduce activities that keep them stimulated when they should be preparing for sleep.
‘If you only have a limited window in which you can sleep, don’t spend part of that time on your phone or doing things that can wait. Create a routine that tells your body it is time to wind down,’
Mr Amanya says, calling for reduction of bright light and screen exposure before bed and keeping the bedroom dark, quiet and comfortable.
Coffee and energy drinks are a quick response to tiredness for several people, but Dr Atuhaire says international health guidelines generally recommend limiting caffeine to 400mg per day or less for most adults.
‘Caffeine makes you feel more awake because it blocks some of the signals in the brain that make you feel sleepy. However, it can remain in the body for several hours and, when taken too late in the day, may interfere with the next night’s sleep, which can create a cycle,’ he said.
Mr Amanya also advises people to maintain a balanced diet, stay hydrated and engage in light physical activity to support energy levels and overall wellbeing. However, he cautioned that exercise cannot replace adequate sleep.
Utility
How much sleep is needed?
According to the World Health Organisation (WHO), sleep requirements vary with age.
Newborns aged zero to three months need 14 to 17 hours of sleep a day, while infants aged four to 12 months require 12 to 16 hours, including naps. Toddlers aged one to two years need 11 to 14 hours, while children aged three to five years require 10 to 13 hours.
School-age children between six and 12 years should get nine to 12 hours, while teenagers aged 13 to 17 years need eight to 10 hours.
Adults aged 18 and above need seven to nine hours
Dr Justus Atuhaire, a physician at Mulago hospital, says people should not mistake their ability to stay awake for evidence that they have adapted to needing less sleep.
‘You can train yourself to tolerate the feeling of tiredness, but you cannot train the body to stop needing sleep. The fact that someone says, ‘I only sleep five hours, and I am fine,’ does not necessarily mean that their brain and body are functioning at their best.’