Fartlek, which means "speed play" in Swedish, is a form of interval training that uses the body's energy systems at different intensities and time periods, varying and alternating frequently. This puts the bodys energy systems under acyclic stress, better mimicking sports specific energy demands. The qFartlek, a reduced version of our FartlekDrill App, allows you to quickly train selecting a drill based on an intensity level and sport. Also, you can customize the drill time distribution scheme to better suit your training needs.The qFartlek App runs in the random mode, in which the engine generates the number of stages, intensities and times based on a sport or your own time distribution (percentages) scheme, and a given intensity.Using the In-App Upgrades you can upgrade the App to include all of the FartlekDrill App features, including the Detail Setup, which allows you to fully customize and saver your own drills, as well as to enable for multiple users.Additionally, can upgrade to the Sports Zoning Module. This module allows you to configure a time distribution scheme, save it as a sport and use it in any Fartlek Drill as you use the default sports.Also, with the In-App you can add the features of our popular AeroRadar App to help you plan and set your training objectives.Features Quick drill setup. Random drill modes. Five standard time levels to distribute the total drill time. Set your own time distribution scheme. Help available for user input parameters. Running distance when GPS is available. Sync to iCloud (IOS 6.0+) the databases and share with other devices and our sports Apps. Saves data of a single user. Supports portrait and landscape screen orientation on the "Run Screen". Can lock the screen orientation before running. Listen & control music or audio books while running. Quick access and control of the iPods music, select songs, playlists, audiobooks, etc. Detailed drill information with table of contents. Male or female voice guidance. Several types of announcements. Export the user data by e-mail, in sqlite3, XML and CSV formats. Select metric or US units. Utilities to facilitate registering each user to our Member Center and reporting problems.