The Polar RS400 and RS-400SD were made for goal oriented runners who want to prepare for their first running event or who want to enhance their running experience.

Features of both the RS-400 and the RS-400SD Heart Rate Monitors:

• Polar sport zones that help you train at the right intensity. Polar sport zones provides an easy way to select and monitor the intensity of your training and to follow Polar’s sport zones based training programs. The training is divided into five zones based on percentages of your maximum heart rate: very light (50-60%HRmax), light (60-70% HRmax), moderate (70-80%HRmax), hard (80-90% HRmax) and maximum (90-100% HRmax).
• Interval trainer (HR, pace, distance) guided workouts -- Create your personal multizone workouts with heart rate/speed/
  distance and timing guidance. Polar Interval trainer allows you to create and name your own favorite workouts based on time, heart rate, speed/pace or distance guidance with up to three linked timers or distances and up to three target zones.
• Event Countdown Timer that lets you set your goal and stay motivated. The event countdown timer keeps your motivation high by showing how many days are left before your next running event (e.g. Boston 23 days).
• Wireless ECG accurate heart rate displayed as beats per minute and percentage of max heart rate
• Polar Fitness Test with OwnIndex
• Polar OwnCode
• Polar OwnCal
• 3 heart rate based Target Zones with audible and visual alarm
• Polar Fitness Test based maximum heart rate
• Interval Timers
• Maximum, Minimum and Average heart rate of total exercise
• Average and Maximum heart rate of each lap
• 99 laps
• Exercise Date
• Alternating / repeating countdown timers
• Interval Trainer (heart rate, pace, distance) guided workouts
• ZonePointer with ZoneLock
• Calorie Expenditure (exercise / weekly / total fat percentage) recorded
• Transfer exercise data from wrist unit to polarpersonaltrainer.com via Polar WebLink (SonicLink / Infrared)
• Compatible with Polar ProTrainer 5 software
• 99 exercise files with summaries
• Exercise file info page with date and time
• Total exercise time, time in target zone, target zone limits, average heart rate, lap info, plus last OwnIndex recorded
• Backlight
• Oversized display with easy start
• KeyLock
• HeartTouch allows button-free operation of wrist unit
• Alternating / repeating countdown timers
• Water resistant to 50 meters
• Records exercise time and average heart rate of exercise session
• Watch with time of day, dual time zones, date and weekday indicator
• Low battery indicator
• Lap info
• Memory left indication
• Stopwatch
• Easy start with oversized display
• Event countdown timer
• Display zone
• Graphical target zone indicator
• Displays text in English, German, French and Spanish
• Comes with Polar WearLink 31 coded transmitter with user-changeable battery (compatible with T31 coded transmitters)
• 2 year Polar Warranty

Additional features of the Polar RS400-SD:

• Running Index - based on heart rate and speed data measured during the running exercise. It gives daily information about the runner’s performance level, both aerobic fitness and running economy. Improvement in running efficiency indicates improved economy of running performance
• Speed/Pace and Distance - motivate your training sessions with accurate distance, speed (min/km or min/mile) and pace (km/h or miles/h).
• Auto lapping - Set your running computer to automatically take laps at preset distancies. With this feature you can set your running computer to take laps based on distance, every 1 km, for example
• Interval trainer (HR, pace, distance) guided workouts - Create your personal multizone workouts with heart rate/speed/ distance and timing guidance. Allows you to create and name your own favorite workouts based on time, heart rate, speed/pace or distance guidance with up to three linked timers or distances and up to three target zones.