In recent years, wearables or wearable devices have become a true craze among the fitness public. What started as a simple step counter has transformed into a sophisticated health laboratory that fits on the wrist, on the finger, or even on clothing. With the arrival of new advanced sensors and features driven by artificial intelligence, wearables are redefining the concept of self-care and crossing the boundaries of preventive medicine.

Projected to reach $70 billion in 2025, according to Statista, the wearable market has become one of the most advantageous, both for brands and users. Research from the University of California has shown that users of this type of device showed up to a 25% reduction in hospital visits due to more effective management of their chronic conditions. In Brazil, 30% of the population already uses some wearable health device, and the trend is for accelerated growth. By 2030, IDC predicts that 70% of adults in developed countries will use wearables.

But, anyone who thinks this technology is extremely recent is mistaken. In this article, you will learn about the history of these devices, find out which are the best wearables of 2025, as well as discover the innovations that are to come. 

The trajectory of wearables

The history of smart wearable devices began decades ago, long before they became part of our daily lives. Although digital watches have existed since the 1970s — with Hewlett-Packard's HP-01 in 1977 being considered the precursor of smartwatches, featuring a calculator and data storage —, it was only in the 21st century that wearable technology gained a real focus on health and fitness.

The turning point occurred in 2007, when James Park and Eric Friedman founded Fitbit Inc. in San Francisco, California. In 2009, the company launched the Fitbit Tracker, the first wearable device focused on monitoring physical activities sold on a mass scale globally. That simple step counter revolutionized the market by popularizing the idea that people could track their daily health metrics.

With Fitbit leading the way, other companies soon realized the potential of this market. In 2012, the Pebble Watch was born through a crowdfunding campaign, considered the first modern smartwatch, laying the groundwork for the creation of more evolved devices. But, it was in 2015 that the wearable market definitively exploded with the launch of the Apple Watch by Apple, which brought elegant design, smartphone integration, and increasingly advanced health features.

From then on, tech giants like Samsung, Google (which acquired Fitbit in 2021), and Garmin entered the race, while innovative startups like Oura began exploring alternative formats, such as smart rings.

From step counter to portable clinic

Steps taken, distance traveled, calories burned, and sleep quality were the main metrics of the first wearables. While useful for the fitness public, this information was relatively limited from a medical standpoint.

The true transformation of these devices began when manufacturers incorporated more sophisticated sensors into their models. Learn about some of them below. 

Continuous heart rate monitoring
Modern smartwatches can measure heart rate 24 hours a day using optical sensors (photoplethysmography). More importantly, devices like the Apple Watch introduced electrocardiogram (ECG) functionality in 2018, allowing users to detect cardiac arrhythmias, especially atrial fibrillation — a condition that affects more than 20 million Brazilians, according to the Brazilian Society of Cardiac Arrhythmias (Sobrac) and can lead to sudden death if undiagnosed.

Pulse oximetry (SpO2)
Oxygen saturation measurement in the blood has become standard in many wearables, being crucial for identifying respiratory problems and conditions like sleep apnea. The Galaxy Watch 7, for example, received approval from Anvisa in 2025 for detecting sleep apnea, an innovation that can transform the lives of millions of people who suffer from this disorder without even knowing it.

Body temperature
Integrated temperature sensors allow tracking variations that can indicate anything from the onset of an infection to hormonal changes in the menstrual cycle. The Oura Ring smart ring stood out in this area, managing to detect even early signs of COVID-19 before symptoms manifested.

Glucose monitoring
One of the most promising frontiers is non-invasive glucose monitoring. Startups like Quantum Operation have already developed prototypes of wearables with spectrometers that measure blood sugar levels through the skin, without the need for finger pricks — something revolutionary for the more than 12% of the Brazilian population living with diabetes.

The best wearables of 2024-2025

The current market offers an impressive diversity of wearables, each with its specialties. Check out some of them, starting with the Apple Watch:

Apple Watch Series 10
Continues to be the benchmark in integration with the iOS ecosystem, offering comprehensive health monitoring with ECG, SpO2, fall and arrhythmia detection, in addition to communication features and various apps. The S10 chip uses artificial intelligence to predict fall risks in the elderly.

Apple Watch Ultra 2
Robust and premium version with extended battery, larger screen, and advanced features for athletes and adventurers. 

Samsung Galaxy Watch 7
Android device with Wear OS that now includes certified sleep apnea detection, as well as heart rate monitoring, SpO2, and GPS. Offers excellent integration with Samsung smartphones.

Samsung Galaxy Watch Ultra
Samsung's first foray into the rugged smartwatch market, competing directly with the Apple Watch Ultra.

Fitbit Charge 6
For those looking for something more focused on fitness without giving up health, this tracker offers 7 days of battery life, heart rate monitoring, SpO2, and sleep analysis. It is a more affordable option than full smartwatches.

Google Pixel Watch 3
Arrived in 2024 with a 45mm model, offering improved battery life and native integration with Google services, including Fitbit Premium.

WHOOP 4.0
Aimed at serious athletes, it continuously monitors strain, recovery, and sleep, providing personalized recommendations on when to train or rest. Discreet design for 24/7 wear.

Xiaomi Smart Band 9
It is the most economical option for those who want to start in the world of wearables without spending much, while keeping essential features like heart rate and sleep monitoring.

Smart rings and clothing: the new frontier

While watches gain more sophistication and customization through bands, accessories, and endless color choices, smart rings emerge with the promise of offering discreet and comfortable monitoring, especially during sleep. 

Oura Ring 4
Launched in 2024, this model is considered a benchmark among smart rings. Available in six finishes (including gold and rose gold) and 12 sizes (from 4 to 15), it monitors heart rate, heart rate variability (HRV), body temperature, sleep, and even the menstrual cycle. It costs between $349 and $499, requiring a monthly subscription of $5.99 for full access to insights. Compatible with iOS and Android.

Samsung Galaxy Ring
Launched in July 2024, it is Samsung's response to the Oura Ring. Thinner (7mm vs 7.9mm) and lighter (2.3g vs 3.3g), it offers monitoring of sleep, heart rate, physical activities, and even device control by gestures (pinching fingers). Available in three colors and sizes from 5 to 13, it costs $399 with no monthly subscription required. Limitation: works only with Android smartphones, especially Samsung.

RingConn Gen 2 Air
This is a more affordable alternative to the Oura Ring, with long battery life and similar features at a lower cost.

Smart clothing
In 2025, clothing with sensors integrated into the fibers already measures heartbeat, posture, calories, and muscular fatigue, connecting to health apps in real time. Professional athletes and functional training enthusiasts are adopting these items to prevent injuries.

The future promises even more

Despite impressive advances, wearables still face challenges, and data accuracy is the main one. This is because sensors can have a margin of error between 5 and 10% in metrics, a percentage that positions them as complementary tools, not replacements for proper medical follow-up. Other challenges include cost, accessibility, battery life, and data privacy.

Even with all the challenges, innovations do not stop. The market already predicts the launch of:

• Fully non-invasive glucose sensors integrated into smartwatches.

• Early detection of more diseases, including some types of cancer through biomarkers.

• Deeper integration with telemedicine systems, allowing doctors to monitor patients remotely in real time.

• Solid-state battery in smart rings, further increasing battery life.

• Expansion of augmented reality with smart glasses focused on health.

• More affordable smart clothing for the general public.

With the expansion of 5G and the advancement of artificial intelligence, wearables are increasingly becoming essential in the digital health journey. By putting users as protagonists of their own care, these devices democratize access to health information and promise to transform preventive medicine.

The wearable revolution is not about replacing doctors or specialized care, but rather empowering people with knowledge about their own bodies, allowing for faster interventions and more effective treatments. In a world where prevention is increasingly valued, these small devices can make a huge difference between detecting a problem in time or too late.