Exactly what long car journeys do to your body

Telegraph

15 hours ago

If you spent your childhood in Britain, you likely have memories of many a car journey: the early starts, the packed lunches, the boots full to the brim. Then there are the hours spent playing I Spy and singing, driving through the countryside, to get to the seaside, holiday camps or visit family. Long car journeys are quintessentially British. And such trips came into their heyday in post-war Britain, when car ownership had become more common and trips abroad were unusual.
While the advent of the cheap package holidays to Spain (where good weather is nearly guaranteed) reduced the number of people flooding seaside towns, so-called 'staycations' are in demand for their cost and convenience.
However, it does mean hours in the car and the familiar feelings of tiredness, travel sickness and muscle aches that it brings. So, what's actually happening in our bodies, and what can we do to keep in good health during the journey?
Tiredness
It's common for passengers to nod off on long journeys, but obviously, it is extremely dangerous if the driver succumbs to drowsiness – between 10 and 20 per cent of all crashes are caused by fatigue. 'For the driver, tiredness will eventually kick in,' says Prof Charles Spence, an experimental psychologist at the University of Oxford, who researches car design and how it affects driving.
Studies suggest that, beyond just the mental effort of driving, driving can induce sleepiness within 15 minutes due to the natural vibrations of car seats, while the white noise made by the engine, wheels and passing cars is also thought to play a role.
'Several car companies' idea of success in recent years was to design car interiors such that when commuters got home at the end of day, they would just sit in the driveway because the multisensory environment was so comfortable,' Prof Spence says. 'Ultimate comfort might not be ideal for keeping a driver on a long journey in peak state of arousal or alertness.'
How to prevent it
'Opening a window to get some fresh air can help,' Prof Spence says. 'But ultimately, presumably, the thing to do is take a break.'
Some cars now come with driver drowsiness detection, which makes a loud noise or causes the wheel to vibrate when it senses – by analysing speed, time of day and weather – a driver might be becoming tired. 'Cars can monitor drivers nowadays, but an urgent alert sound may be too unpleasant,' Spence says.
Getting enough sleep the night before a long journey is also key. Research shows that drivers who get less than five hours of sleep are just as likely to crash as if they were over the legal limit for alcohol.
Motion sickness
During a long car journey, around one in three of us will experience the symptoms of motion sickness to some degree, from mild nausea to vomiting that forces us to pull over.
It's thought that motion sickness is a result of a sensory mismatch between the movement the body is experiencing (sensed by the inner ear) and the movement that we're seeing (logged by our eyes), explains John Golding, professor of applied psychology at the University of Westminster, who has previously worked with RAF pilots and sailors in the navy to desensitise them to motion sickness.
Experts believe the resulting unpleasant symptoms occur because the body believes that this sensory mismatch is a sign that it has been poisoned, he explains.
'In response, the brain tells the stomach to stop moving its contents further through the gut (a protective reflex called gastric stasis) because, according to this poison detector theory, that would be preventing any further poison from being absorbed,' he says.
While some people never suffer from queasiness in the car, others reach for a plastic bag on every long car journey. This is a result of an accumulation of risk factors, Prof Golding says.
Women are more susceptible than men, as are people who suffer from migraines, and there is a genetic element as well, with research showing that there are 35 genetic markers that contribute to motion sickness. Age is also a factor, with children between eight and 10 most likely to suffer.
'Drivers hardly ever become sick because the car becomes an extension of their body and they control the motions of the car as they steer into curves or brake or accelerate,' Prof Golding notes. 'But for the poor passenger, they're not in control.'
How to prevent it
'There are three basic approaches,' Prof Golding explains. The first is to expose yourself enough times so you get used to the sensation – an approach used to desensitise RAF pilots, he says. 'However, that's time-consuming, and if you're not frequently making long car journeys, this might not be the best option for you,' he notes.
Another approach is to try behaviours that limit the severity of motion sickness, such as sitting in the front passenger seat and focusing on the road ahead to anticipate the movement, which reduces sensory mismatch, he explains. 'Sitting in the back seat and looking out at flashing scenery as you drive by is no good,' he notes.
Some turn to acupressure travel bands (wrist bands with a plastic button attached, which is placed over the centre of the wrist). 'Trials show that they work as well as a placebo, but the placebo effect can be wonderful, so they really do work for some people,' he says.
Avoiding looking at your phone, reading a book or moving your head around too much, as this will only worsen the sensory mismatch, Prof Golding says.
The third option is anti-sickness drugs. These include hyoscine hydrobromide (sold under brand names including Kwells) and cinnarizine (branded as Stugeron).
These work by preventing symptoms and typically need to be taken an hour before you get in the car, Prof Golding notes. 'There's no point in taking it once you start to feel even slightly queasy, as at this point, gastric stasis has already occurred, so you won't be able to absorb it,' he notes.
Some companies are developing devices that they hope will target motion sickness. One example is Apple's 'vehicle motion cues', which allows iPhone users to have six static dots on their screen, which, once a person is in a moving car, shift in the direction of travel in a bid to reduce motion sickness.
'It does not provide any anticipation of the motion – it is not a 'warning cue',' Prof Golding notes. 'I would have doubts about the usefulness of this phone software. Especially because it is making the passenger concentrate on looking at the screen. We know that reading, looking down at mobile device screens, tends to exacerbate motion sickness.' It might help some people but will likely make things worse for most, he adds.
Gut discomfort
Long journeys in the car disrupt our usual routines, throwing our activity levels and eating habits out of whack, which has a knock-on effect on how our gut is feeling.
'People often drink less water when travelling, snack at odd times and disrupt their normal bathroom habits,' notes Dr Emily Leeming, a microbiome scientist and dietitian. This isn't helped by the food available at petrol stations and motorway services, which is often ultra-processed convenience food.
Additionally, sitting for long periods of time can slow down gut motility for some people, which are the wave-like muscle contractions that move food and waste through your gut, she notes. Each of these factors contributes to sluggishness and can lead to bloating, wind and constipation, Dr Leeming notes.
How to prevent it
'Try getting out of the car for regular breaks, go for a short walk or do some stretches every few hours to help stimulate your digestion,' she suggests. 'Take a water bottle with you to stay hydrated.'
Dr Leeming also recommends trying to eat your meals at the same time you would if you're not travelling. If you want snacks for the car, nuts and fruit like bananas and apples are great choices, she says. 'They'll keep you feeling full and also provide plenty of fibre and other nutrients.'
Tight-fitting clothes, like jeans, dresses and skirts, can put extra pressure on the abdomen, which traps gas and slows digestion, which makes any bloating feel even more uncomfortable. 'So, wear loose-fitting bottoms when you're travelling instead, that have some give around your stomach,' she says.
Muscle stiffness
Tense shoulders, tight calves and back pain are common grumbles from drivers and passengers during long stints in the car.
This is a consequence of remaining in a seated position for too long, though, for drivers, the small adjustments in the neck, shoulders, arms, lower back and lower limbs that our bodies make while behind the wheel is also a factor, explains Prof Lee Smith, a professor of public health at Anglia Ruskin University, who has expertise in sedentary behaviour.
'Sitting for too long, particularly in a position that is not aligned with the natural curves of our spine, can contribute to a number of musculoskeletal problems,' he adds.
These include lower back pain and stiffness, neck tension, shoulder strain and lower limb fatigue and stiffness from operating pedals, as well as sciatica-like symptoms from poor hip positioning.
How to prevent it
Prof Smith recommends scheduling a break in your drive every two hours, giving yourself and your passengers enough time to stretch and have a short walk. Passengers can also stretch out their neck, arms and legs while in the car.
Additionally, the Royal Automobile Club recommends checking your driving set-up to prevent muscle stiffness, aches and pains. You can do this by making sure the seat is upright at around a 100-degree angle; ensuring your head is centred in the middle of your headrest; adjusting wing and rear-view mirrors so you don't need to twist to see out of them; and making sure your back and shoulders touch the backrest when your hands are on the steering wheel.
Poor blood flow
Beyond our muscles, sitting for too long can also lead to problems with blood flow, says Prof Smith. 'It can contribute to the prevention of effective circulation of blood through our bodies, and this can cause blood to pool in the veins of the legs,' he says.
'Sitting uninterrupted for long periods of time can ultimately cause deep vein thrombosis (DVT), a type of blood clot that forms in a vein,' he says.
Normally, blood flows through the veins, helped by movement in your muscles. However, if you are seated for too long (typically four hours or more), the flow of blood can slow down and pool in the veins, causing a clot to form, which either partially or completely blocks a vein. Common symptoms include swelling and pain but there may be no signs of a clot.
'The clot can break free and travel to the lungs, causing a sudden blockage of arteries in the lung, known as a pulmonary embolism,' Prof Smith explains. 'Although serious, these types of blood clots are rare.'
How to prevent it
When in the car for three hours or more, the NHS recommends taking breaks where possible to walk around, as well as wearing loose-fitting clothing that doesn't prevent blood flow, drinking plenty of water and avoiding alcohol. While typically associated with long-haul flights, compression socks can be worn on long car journeys to encourage blood circulation.
'If a passenger in the vehicle, exercise your calf muscles and exercise your legs while sitting,' Prof Smith recommends. 'For example, you could raise and lower your heels while keeping your toes on the floor, raise and lower your toes while keeping your heels on the floor, and tighten and release your leg muscles.'