From digital insoles that correct your gait to bracelets that track your fertility, wearable health technology is a booming industry.
But are these gadgets – which can be incredibly expensive – an accurate way of checking our health?
“Fitness trackers can help motivate us to exercise and make us more aware of our well-being,” says Professor Ian Swaine, a sports and exercise scientist at the University of Greenwich.
“However, novelty often wanes, and while there have been significant advances in recent decades, the technology involves sensors that are not always reliable, combined with computer estimation and algorithms that turn the numbers into results – and research has shown this.” may be subject to inaccuracies.’
dr Nisa Aslam, a London-based GP, adds that while some of this technology can help monitor conditions like diabetes, “initial health assessments and annual check-ups still need to be conducted in person by a doctor.”
We have Professor Swaine and Dr. Asked Aslam for her opinion on some of the latest gadgets; We then rated them.

From digital insoles that correct your gait to bracelets that track your fertility, wearable health technology is a booming industry
activity and heart clock
Fitbit Charge 5, £129.99, fitbit.com
Claim: The “most advanced” Fitbit, which monitors activity, heart rate and sleep patterns, checks for “irregular heart rhythms” with an EKG, and measures stress with an electrodermal activity sensor (EDA), the manufacturer says. A daily “readiness assessment” advises exercise or rest.
Expert verdict: “This reflects the trend towards home healthcare management, fueled in part by the difficulties of seeing GPs face-to-face,” says Professor Swaine. “But a wrist monitor should never replace a doctor when it comes to heart health because wrist sensors can’t measure irregular heart rhythms very accurately.”
“It claims to identify stress levels through an EDA sensor – by measuring skin sweating – but we sweat for many reasons.
“The ‘Readiness Score’ could help raise your awareness of the need to rest sometimes, but overall there isn’t much science to back up the new features.”
5/10
Patches for monitoring blood sugar levels

FreeStyle Libre 2, £96.58
FreeStyle Libre 2, £96.58, freestylelibre.co.uk
Claim: This stick-on sensor connects to an app and can be used to “check your glucose levels anytime, anywhere with just a scan of your smartphone.” An alarm on your phone will sound if the levels are too high or too low.
Expert verdict: “This clinically accurate device is a game changer for people with type 1 and type 2 diabetes and is available to some in the NHS,” says Dr. Aslam.
“The small, discreet sensor, worn for 14 days, monitors glucose levels in interstitial fluid — the clear fluid that sits just under the skin — relieving patients of the hassle and pain of fingerstick blood glucose testing.
“The readings show whether the glucose trend is up or down. An alarm alerts patients when their glucose levels are too low or too high. That saves a lot of trouble and offers security.”
9/10
Bracelet that monitors fertility
Ava Fertility Tracker, £249, avawomen.com

Ava Fertility Tracker, £249
Claim: This bracelet helps women track their monthly cycle by monitoring nine “biomarkers,” including skin temperature, respiration, heart rate, and blood flow. Worn overnight, it tells you every morning if it’s a good day to try with a baby. The manufacturer says it can identify an average of “five fertile days per cycle with an accuracy of 89 percent.”
Expert Verdict: “Studies show that temperature and heart rate change throughout a woman’s menstrual cycle and increase around the days of ovulation, when an egg is being released from the fallopian tubes and a woman is at her most fertile,” says Dr. Aslam.
“Tracking these factors can indicate when ovulation occurs with a fairly high degree of accuracy.
“There is solid research behind this, but this bracelet is very expensive. I suggest that patients keep a journal of cheap, pharmacy-bought ovulation tests. That’s enough for most.’
7/10
Sleep tracker that you put in your pocket
WHOOP 4.0, £264, whoop.com
Claim: Worn on the wrist or tucked into the inside pockets of sports bras and pajamas to “monitor heart rate, breathing rate, blood oxygen levels, and skin temperature, it also tracks sleep and breathing patterns,” the manufacturer says.
Expert verdict: “Monitoring heart rate and physical movement during sleep provides little information, but measuring overall sleep quality requires a polysomnogram — a brain scan in which electrodes measure brain waves, muscle movements, respiration and heart rate,” Professor says Swaine.
“Using these types of trackers can make people obsess over how many hours of sleep they’re getting. A better test is how you feel about your everyday activities.”
4/10

Worn on the wrist or tucked into the inside pockets of sports bras and pajamas to “monitor heart rate, breathing rate, blood oxygen levels and skin temperature, it also tracks sleep and breathing patterns,” the manufacturer says. A file photo is used above
Heart rate earplugs
Amazfit PowerBuds Pro, £59, amazon.co.uk

Amazfit PowerBuds Pro, £59
Claim: These wireless earbuds “measure your heart rate while you exercise” and give “posture reminders” if you sit too long.
Expert verdict: “Measuring heart rate during exercise can theoretically help you regulate your exertion during exercise – and gauge how hard you’ve been working,” says Professor Swaine.
“This works well for aerobic exercise like running or cycling, but it’s not as useful for resistance exercise like weights or Pilates, where you can work your muscles hard.
“Ear monitors measure heart rate by changes in reflected light as it penetrates the skin in the ear – but chest monitors are more accurate because they’re closer to the heart.
“The ‘posture reminder’ is based on the idea that when you sit more, you are less active.
“However, research shows that you derive health benefits from certain periods of exercise, so the jury is out on how beneficial this is.”
7/10
Bracelet against snoring
Viatom sleep pulse oximeter, £134.99, stressnomore.co.uk
Claim: A wrist monitor that measures blood oxygen levels to “help Covid patients spot deterioration”. It also functions as a “sleep apnea monitor,” the manufacturer says.
Expert verdict: “Sleep apnea is a condition in which breathing stops temporarily during sleep, leading to snoring and a drop in oxygen levels,” says Dr. Aslam.
“This bracelet and finger sensor monitors oxygen levels while you sleep and vibrates when it drops to a preset low level. It could be useful for people with sleep apnea, Covid-19, pneumonia and COPD [chronic obstructive pulmonary disease, a term for conditions which cause breathing problems]warning the wearer to seek medical help early.
“A far cheaper alternative is a pulse oximeter you clip to your finger, which costs around £10 and is very accurate.”
8/10
Watch to check hydration
Mifo Walkabout Watch 2, £69.99, mifo.co.uk
Claim: “A waterproof smartwatch that measures heart rate, blood oxygen, hydration, sleep patterns and stress levels,” says the manufacturer.
Expert Verdict: “Hydration is predicted based on how much exercise you’ve been doing and how much water you’re likely to have lost [about one litre per hour during exercise] – it can’t really measure the water level in our cells,” says Professor Swaine.
“Most people know that they should avoid exercising without water. You should use feelings of thirst to determine how much water you are drinking.
“It also claims to measure stress through ‘heart rate variability.’ However, these fluctuations are notoriously difficult to measure and accurately interpret.
“However, it’s a budget-friendly general fitness tracker.”
6/10
Insoles to improve your gait
Digitsole, £89.99, decathlon.co.uk
Claim: Digital insoles that promise to measure “ten aspects of your walking or running technique,” says the manufacturer, “to improve your stride and efficiency.”
Expert verdict: “These contain embedded sensors that measure changes in pressure as you walk or run,” says Tim Veysey-Smith, a sports podiatrist at Active Podiatry in Goudhurst, Kent.
“This helps measure stride length, foot strike pattern, and rate of pronation and supination [rolling in and out of the foot, respectively].
“But knowing what to do with the data can be difficult. You must work with a qualified expert for it to be properly interpreted.’
7/10
