Fitness & Wellness Wearables in 2025: Current Capabilities & Market Gaps

Tyler Brown
Jul 31
3 min read

Introduction

Wearable fitness and wellness trackers have exploded in popularity, evolving from simple step-counters to sophisticated health monitors. In 2025, over 450 million people worldwide use smartwatches – a market worth around $50 billion – and 92% of users rely on these devices to track and improve their health and fitness [1]. From smartwatches by Apple, Samsung, Garmin, and Google (Fitbit), to dedicated fitness bands like WHOOP, smart rings like Oura, and even continuous glucose monitors (CGMs) repurposed for everyday wellness, consumers have no shortage of options. These wearables continuously collect data on our bodies — heart rate, sleep quality, activity levels, and more — providing unprecedented insight into personal health.

In this deep dive, we’ll explore what data today’s leading wearables collect, how different devices specialize in various metrics, and importantly what gaps remain in the market (e.g. hydration and nutrition tracking). Investors, health professionals, startup founders, and tech enthusiasts will gain a comprehensive overview of the current wearable landscape and opportunities for innovation.

1. Key Health Metrics Tracked by Modern Wearables

Heart Rate & ECG: Apple, Garmin, Fitbit, and others offer 24/7 heart rate monitoring, with ECG apps now FDA-cleared for on-demand rhythm checks [2][6]. WHOOP and Apple include heart rate variability (HRV) for recovery insights [3].
Activity & Training Load: Garmin and Apple lead in GPS accuracy and detailed workout tracking. WHOOP and Garmin also quantify “strain” or “training load” metrics [3].
Sleep & Recovery: WHOOP and Oura dominate here with detailed sleep staging and composite recovery scores. Garmin uses “Body Battery,” Apple integrates sleep with health metrics, and Fitbit provides a “Sleep Score” [3][4][16].
Stress & Mood: Fitbit includes an electrodermal activity (EDA) sensor, while Garmin and WHOOP use HRV-based stress models [5][16][17].
SpO₂ & Respiration: Most devices now include oxygen saturation sensors and respiration tracking during sleep [16].
Temperature & Female Health: Oura and Apple Watch Series 8+ track overnight skin temperature for illness detection and cycle tracking [4][14].
Glucose: CGMs like Dexcom and Abbott (via NutriSense and Levels) allow wellness-focused real-time glucose tracking [7][8].
Body Composition: Samsung, Fitbit, and Withings offer body fat estimates via bioimpedance. Lumen offers breath-based metabolism insights [4].

2. Who Measures What

Metric	Apple Watch	Garmin	WHOOP	Oura Ring	Fitbit	CGMs (Dexcom, etc.)
Heart Rate / ECG	✅ [2]	✅ [6]	✅ [3]	✅	✅	—
Sleep & Recovery	✅	✅ [16]	✅ [3]	✅ [4]	✅	—
Stress / EDA Sensor	⚪	✅ [16]	✅ [17]	⚪	✅ [5]	—
Skin Temp / Cycle Tracking	✅ [14]	⚪	✅	✅ [4][14]	✅	—
Glucose	⚪	⚪	⚪	⚪	⚪	✅ [7][8]
Hydration / Electrolytes	❌	❌	❌	❌	❌	⚪ [9][10]

3. Market Gaps and Opportunities

Hydration Tracking: No major smartwatch tracks hydration directly. Sweat-sensing patches like Gatorade Gx and Nix Biosensors show promise but aren’t mainstream yet [9][10].
Nutrient / Protein Feedback: Devices can’t yet detect amino acids or protein status. A 2023 prototype called “NutriTrek” tracked multiple nutrients via sweat [11].
Lactate, Cortisol, Ketones: Still in early R&D. These would unlock real-time stress, fueling, and metabolic insights [11][12].
Medical-Grade Accuracy: Current wearables can be imprecise under motion. Ultrasound patches and next-gen biosensors aim to close this gap [12].
Actionable Coaching: WHOOP and Garmin provide some real-time training guidance, but full-body, AI-driven insights remain rare [3][16][17].

4. Culture Meets Tech

Biohacking culture has propelled wearables into the spotlight. The Oura Ring has become popular among longevity enthusiasts and founders. WHOOP leads among athletes. CGMs (via Levels or NutriSense) have birthed a metabolic optimization movement [7][8][13].

5. Competitive & Investment Landscape

Big Players: Apple, Google, Samsung innovate around UI/UX and safety. Abbott and Dexcom expand CGMs into wellness.
Startups:
- NutriSense and Levels = CGMs for non-diabetics [7][8]
- Nix Biosensors = hydration biosensor [10]
- Epicore (Gatorade Gx) = sweat patch [9]
- Lumen = breath-based metabolism tool [4]
- NutriTrek / Labs = nutrient tracking in sweat [11]

Bottom Line / Outlook

Wearables have redefined self-monitoring — but they’re far from finished. Expect innovation in:

Real-time hydration and nutrition sensing
Multi-device integration
AI health coaching
Wearable chemistry — glucose, amino acids, hormones

The next frontier? A 24/7 wellness coach on your wrist? Perhaps.