Intervals.icu

Intervals.icu analyzes your rides, runs, swims and other activities (with and without power). It provides basic and advanced analytics and planning in an easy to use web interface with support for desktops, phones and tablets. Follow your friends and help them progress, track your FTP without doing tests, coach other athletes, communicate with the built in chat, build a workout library (for outdoor, Zwift and others) and plan your training!

Intervals.icu is free but please consider supporting the project with a $4/month subscription if it is working well for you. You can do this from the settings page in the app. The monthly hosting costs are substantial as is the time required to keep everything running. Supporter feature requests move up the todo list!

Track Your Progress

Fitness, Fatigue and Form Chart

• Fitness, freshness and form chart with annotations that shows future impact of your training plan
• Complete history downloaded from Strava, Garmin Connect and Suunto
• Download new activities from Polar
• Download fit, tcx and gpx files from Dropbox
• Upload your own fit, tcx and gpx files
• Automatic FTP estimation (eFTP) from a single maximal effort, no need for tests!
• Training load estimated from activities with power (standard Coggan formula), heart rate or pace data and swims
• Form as an absolute number or a percentage of fitness

Multisport

• Separate training zones and other settings for each sport
• Use built in zones or define your own
• Elevation correction and gradient adjusted pace supported for runs
• Calculate training load from power, heart rate and/or pace data
• Choose to perform planned workouts on power, heart rate or pace

Power Curve Chart

• Power curve with comparison to previous seasons, watts, watts/kg and MAP calculation (Pinot & Grappe 2014)
• Power modelling using Intervals.icu's own algorithm (eFTP, predefined curves and Mortons 3P), Morton's 3 parameter CP model or Monod & Scherrer's 2 parameter CP model
• Show sub-maximal efforts
• Define your own curve points
• Separate power curves for each sport (cycling, running with Stryd, rowing etc.)

Power Rankings

• Compare yourself to other Intervals.icu athletes in the same age group and see what kind of rider you are
• Charts and rankings in watts/kg and watts (for the big guys!)

Activity Totals

• Totals page with totals by sport and combined time in zones for any date range
• Classifications from FastFitness.Tips

Wellness Integration

• Capture weight, sleep, sleep score, sleep quality, average sleeping HR, resting HR, HRV rMSSD, HRV SDNN, readiness, kCal consumed, blood glucose, menstrual cycle (including future prediction), soreness, fatigue, stress, mood, motivation, hydration, hydration (L), SpO2 and blood pressure
• View them on the calendar and plot them over time on the fitness page to get a more complete picture of your training status and recovery
• Automatically download wellness data from Garmin Connect, Polar Flow, Oura ring, Google Fit and from Apple Health via the HealthFit app
• Download weight from Strava
• Build your own integrations using the Intervals.icu API

Build Your Own Charts

• Create custom time charts from more than 70 different plots with 10 different aggregates and filtering
• Heartrate recovery, power / HR, power / HR in Z2, cadence in Z2, efficiency, intensity, RPE, work done, work above FTP (WAR), time in power zones, time in HR zones, training load, fitness, fatigue, form, ramp rate, calories burned, distance, moving time, climbing, estimated FTP, W prime, weight
• All the wellness parameters (sleep, weight, HRV etc.)

Compare Time Periods and Athletes

• Compare different time periods and athletes
• Plot power vs heart rate to track fitness without any tests
• Build your own comparison charts

Manage Your Activities

• List activities on a grid with 70+ columns to choose from
• Click on the headers to sort
• Apply operations (e.g. adjusting power) to multiple activities at once

Analyze Your Activities

Activity Timeline Chart

• Activity analysis with all the Coggan metrics and others only found on Intervals.icu
• Automatic interval detection, no need to use the lap button!
• Automatic power and heart rate spike detection and fix
• Power, matches burned, heart rate, cadence, torque, W'bal, speed, pace, work done, altitude, temperature and gradient charts
• More than 50 different metrics for each interval and zoomed portion of the chart
• Season achievements for FTP and power with email notifications
• Each activity has its own chat for comments from others following you on Intervals.icu
• Customizable power and heart rate training zones based on Joe Friel's 7 zone model
• Zones are often combined into 3 for followers of Dr Stephen Seiler
• Adjust power data by applying a scale and offset to account for power meter differences
• Fix power and heart rate drop outs

Activity Power Charts

• Ride power with time in zones, power curve vs season, last 42 days etc., power histogram and best efforts

Decoupling Chart

• Decoupling chart to track aerobic fitness, as you get fitter you produce more power at a given HR and experience reduced cardiac drift
• Power / HR Z2 tracks your watts over HR for the parts of the ride done in heart rate zone 2 and is a useful measure of aerobic fitness

Dr Seiler Inspired Decoupling Chart

• This chart inspired by a Dr Stephen Seiler video shows a 60s moving average of power as a percentage of eFTP and heart rate as percentage of HR reserve and is another way of visualising decoupling (HR and power traces diverging)

Activity Heart Rate Charts

• Ride time in heart rate zones and heart rate duration curve

Cumulative Heart Rate Time Chart

• Cumulative time at or above a given heart rate, useful to check that your VO2 max intervals are working!

Ride Intervals Table

• Activity interval data is available in table format with CSV download
• Most fields in the UI have popup help when clicked or touched (HRRc shown here)

Interval Search Page

• Search for similar intervals and compare power, torque etc.

Plan Your Training

Training Calendar

• Import calendars from other services to see future fitness
• Build your own workout library and plan your training
• Drag and drop workouts to/from the library and on the calendar
• Upload planned workouts to Garmin and Suunto
• Create training plans
• Share workouts and plans with your friends and coached athletes on Intervals.icu
• Track weekly totals and plan compliance

Workout Builder

• Design your own workouts with the workout builder
• Specify steps with power, heart rate, pace and cadence targets and athletes can choose to perform the workout by power, HR or pace
• Power as percentage of FTP, absolute watts or percentage of the athletes modelled mean maximal power for a given duration
• Heart rate as percentage of max HR or threshold HR
• Import and download workouts in Zwift (ZWO), MRC and ERG format
• Upload to Garmin Connect to synchronize workouts to Garmin devices
• Upload to Suunto to synchronize workouts to Suunto devices

Training Plan Editor

• Drag and drop to create re-usable plans
• Drag a plan onto an athlete's calendar to apply on an ad-hoc basis
• Link any number of athletes to the same plan and apply changes to all of their calendars with one click
• Create one plan and athletes can choose to perform workouts using power, heart rate or pace

Communicate

Share Workouts And Chat

• Chat with other athletes, share rides and workouts, post photos and screenshots
• Create a group for your team, club, riding buddies or coaching business

Ask A Coach For Help

• Use the 'Ask a coach' button on most pages to chat with your coach or one of the Intervals.icu coaches

Keep Track of Your Athletes

• Follow and coach other athletes on Intervals.icu
• Tag athletes to organize them into groups
• Add your coach and they will show up first in the 'ask a coach' list