High Intensity Interval training (HIIT) can be defined as quick, all-out physical activity for a short period of time followed by a rest interval. This journal is designed for runners that want to track their progress with or without utilizing HIIT techniques and principals. This journal is also suitable to use with other fitness activities such as swimming, biking, or rowing. 6 9 inches - convenient and portable Great for runners or any fitness enthusiasts 200 individual tracking sheets Matte finish, paperback cover, white paper.