COLMI P81 Smart Watch Review: The 12-Day Battery Sports Watch That Does It All

The COLMI P81 Smart Watch is built for one type of buyer above all others: the active person who wants comprehensive fitness tracking, doesn't want to charge their watch more than once a week, and needs a watch that can keep up with a varied, demanding exercise routine without compromise. At approximately £40, the P81 delivers 100+ sports modes, 12 days of battery life, continuous health monitoring, and a purpose-built sporty design that communicates its fitness focus from the first glance.

In this full review we cover everything from the P81's sports mode depth and heart rate accuracy to battery performance under heavy fitness use, design, build quality, and how it compares to the closely related COLMI P80 and the GPS-equipped P82 to help you make the right choice.

Design: Purposefully Sporty

The P81 has a clean, athletic design that makes no pretence at being anything other than a fitness-focused smartwatch. The case is well-proportioned, with a comfortable weight and a profile that sits flat on the wrist without protruding awkwardly during dynamic movement. Side buttons are well-positioned and responsive, and the overall construction quality is solid — the watch doesn't feel fragile or hollow when held, reflecting COLMI's improving manufacturing standards.

Available in multiple colour options with silicone straps, the P81 suits both male and female buyers with active lifestyles. The silicone straps are soft, durable, and quick-drying after sweaty sessions or rain exposure. The 20mm strap attachment is standard, allowing aftermarket bands to be fitted if you want to change the aesthetic for different occasions.

Compared to the P80, the P81's design is more uniformly sporty. The P80 offers a stainless steel strap variant that makes it suitable for professional settings as well as the gym. The P81 doesn't offer this — it's designed for active use rather than versatility between sport and office contexts. If gym-to-boardroom versatility matters to you, choose the P80. If sport-focused functionality and aesthetics are your priority, the P81 is the better fit.

IP68 water resistance is standard and covers all daily active use scenarios: sweaty gym sessions, running in rain, muddy trail runs, and post-workout showers (with care — strong shower jets directly on the watch are worth avoiding with IP68 rather than ATM-rated devices).

The 12-Day Battery: What It Actually Means in Practice

Battery life is the P81's headline specification alongside its sports mode breadth, and it genuinely delivers. Under typical conditions — health monitoring active, notifications enabled, always-on display disabled, without GPS — most P81 users report between 10 and 14 days between charges. The manufacturer's 12-day claim is accurate for moderate use and slightly conservative for lighter users.

What does 12-day battery life mean in practice for a fitness-focused user?

• If you train 5 days per week with 45 to 60-minute sessions, the battery handles this comfortably and still lasts 10 to 12 days before needing a charge
• You can travel for a week-long holiday or business trip without packing the charger
• You never experience the "dead watch day" where you forget to charge and spend a day without your health tracker
• Overnight sleep tracking is never interrupted by a flat battery requiring an emergency charge

Compare this to the Apple Watch (18 hours), Samsung Galaxy Watch 6 (3 to 4 days), or even the Garmin Forerunner 55 (7 days) and the P81's battery performance becomes a genuine category-defining advantage at its price point. A fitness watch that lasts twice as long as a Garmin entry-level GPS watch is a compelling proposition for the many users who don't need GPS and do want to stop thinking about charging.

100+ Sports Modes: What's Actually There

The "100+ sports modes" specification appears across many COLMI watches, but it's worth unpacking what this actually means for the P81 specifically. The modes cover:

Outdoor Cardio Modes

Running, cycling, hiking, trail running, walking, Nordic walking, orienteering, roller skating, and others. Each mode uses GPS (phone-connected) to track route, distance, and pace alongside heart rate data. For outdoor training, selecting the appropriate mode before starting ensures the tracking parameters are optimised for your activity.

Indoor Cardio Modes

Treadmill running, indoor cycling, elliptical, rowing machine, stair climbing, jump rope, and others. These modes use accelerometer data and heart rate to estimate calories and effort without GPS. For gym cardio sessions on equipment, these modes provide meaningful calorie and effort data.

Strength and Cross-Training Modes

Weight training, HIIT, CrossFit, circuit training, and others. These modes track session duration, heart rate, and calorie burn during resistance and functional training. While they don't count reps (that's beyond current optical sensor capability), they provide useful session-level data about your training intensity and volume.

Sport-Specific Modes

Football, basketball, badminton, tennis, volleyball, golf, cricket, hockey, rugby, and many others. For team sports and racket sports, these modes track heart rate and session data. They won't provide ball speed or serve speed data, but they capture the physiological demand of your sport effectively.

Mind-Body Modes

Yoga, Pilates, stretching, breathing, meditation, and others. These modes focus on session duration, heart rate, and calorie estimation during lower-intensity, mindfulness-oriented activities.

Water Sports Modes

Swimming, water aerobics, kayaking, rowing, surfing, and others (within IP68 water resistance limits). Casual pool swimming and open water swimming can be tracked, though dedicated swim analytics like stroke counting are not available.

The practical value of 100+ modes is that regardless of how varied your fitness routine is, the P81 has a specific mode for your activity that produces more appropriate tracking data than a generic "other activity" catch-all. For multi-sport athletes who mix running, cycling, strength training, yoga, and swimming across a typical week, the P81's breadth is genuinely useful.

Health Monitoring Features

Continuous Heart Rate Monitoring and Zone Tracking

24/7 optical heart rate monitoring provides resting and active heart rate data continuously. During sports mode sessions, real-time heart rate display on the watch face enables zone-based training — one of the most evidence-based approaches to improving fitness efficiently. Configure your heart rate zones in the Da Fit app based on your estimated or tested maximum heart rate, and the P81 guides you to stay in the right zone during each session.

Accuracy during steady-state cardio (running, cycling) is good — typically within 3 to 7 bpm of chest strap references. During high-intensity intervals or activities with significant rapid arm movement, accuracy can degrade, which is a universal limitation of wrist-based optical sensors. For the vast majority of recreational fitness use, the accuracy is entirely adequate.

Blood Oxygen (SpO2) Monitoring

On-demand SpO2 measurements are available at any time. For fitness-focused users, SpO2 monitoring during exercise recovery provides useful context around how efficiently your body is restoring oxygen saturation after intense efforts. Post-exercise SpO2 recovery speed is a proxy for cardiovascular efficiency that improves with fitness over time.

Sleep Stage Tracking

Automatic overnight sleep detection tracks light, deep, and REM stages. For athletes, sleep quality data is essential recovery information. Monitoring whether your training load is supported by adequate deep sleep, and whether high-intensity weeks correlate with disrupted sleep, gives you the data to manage your training intelligently. The 12-day battery ensures the P81 never dies mid-sleep-cycle, which is a practical advantage over shorter-battery alternatives for consistent overnight data collection.

Recovery Monitoring via HRV

HRV-based stress monitoring provides morning recovery status data. For active users training frequently, checking morning HRV before deciding on training intensity is the most practical daily use of this feature. A low morning stress score (high HRV) indicates physiological readiness for a hard session. A high stress score (low HRV) suggests rest or light activity is smarter than pushing through fatigue.

GPS: Phone-Connected vs Built-In

The P81 uses phone-connected GPS rather than built-in GPS. This means outdoor route tracking works when your phone is within Bluetooth range during your workout. For gym sessions, treadmill runs, indoor cycling, and activities where you carry your phone, this is entirely adequate.

For runners and cyclists who want to leave their phone at home during outdoor sessions, the phone-connected GPS limitation is the primary reason to consider upgrading to the COLMI P82 (built-in GPS, £10 more) or V76 GPS (£22 more). If you always carry your phone during outdoor workouts and don't need phone-free GPS, the P81's phone-connected GPS works seamlessly and saves you the cost premium.

Da Fit App for Training Analysis

Post-workout data syncs to the Da Fit app via Bluetooth, providing session summaries including duration, heart rate average and maximum, calorie burn estimate, and (for GPS sessions) route map and pace chart. Weekly and monthly training summaries show your activity volume and intensity trends over time.

The app stores data indefinitely with no subscription required. For users who want to track their fitness progress over months — watching their resting heart rate decline as fitness improves, or their weekly step count increase as activity habits develop — the Da Fit app provides the longitudinal view that makes this progress visible and motivating.

P81 vs P80: Which P-Series Should You Choose?

The P80 and P81 share the same price point and very similar core specifications. The meaningful difference is design versatility:

• P80 with stainless steel strap: The most versatile watch in the COLMI P-series. Works for gym, sport, office, and professional settings. The steel strap genuinely elevates the look for non-sports contexts.
• P81: Pure sports focus. No steel strap option, but equivalent health and fitness tracking performance in a design that's optimised for active use without concern for professional versatility.

If your life includes professional settings where you want your watch to look appropriate, choose the P80 (steel strap). If you primarily wear your watch for fitness and casual daily use without professional context concerns, choose the P81 and save the small price difference the steel strap option commands.

P81 vs P82: Sports Tracking vs GPS

The P82 adds built-in GPS, a massive 2.13-inch AMOLED display, and Bluetooth calling at a £10 premium over the P81. The P81 wins on battery life (12 days vs 7 to 10 for the P82 in non-GPS use).

The decision point: do you need phone-free GPS tracking for outdoor workouts? If yes, the P82's additional cost is justified. If you're satisfied with phone-connected GPS or primarily train indoors, the P81 delivers equivalent sports tracking at a lower price with longer battery life.

Who Should Buy the COLMI P81?

• Multi-sport athletes who want a single watch covering all their training activities
• Fitness enthusiasts who want 12-day battery life above almost any other specification
• Gym-focused users who don't need standalone GPS but want comprehensive workout tracking
• Active users who travel frequently and want a watch that lasts the whole trip on one charge
• Those who value variety of sports modes for a diverse training routine
• Buyers who want the P80's performance without paying for the steel strap option

Verdict

The COLMI P81 is an outstanding fitness smartwatch that delivers exactly what its target audience needs: comprehensive sports tracking across 100+ modes, exceptional 12-day battery life, continuous health monitoring, and a purposeful sporty design at a genuinely accessible price. It's not the flashiest watch in the range — the P86's curved AMOLED and the P82's GPS both offer more visual drama — but for the active user who primarily wants reliability, feature breadth, and long battery life, the P81 is one of the best-value fitness watches available anywhere under £40 in 2026.

Rating: 4.4 / 5 — The best pure fitness watch in the COLMI lineup. Outstanding breadth of sports modes, exceptional battery life, and solid health monitoring make it a compelling choice for active users who train consistently and variously.