HIIT training is probably the only viable shortcut the fitness there is. The HIIT Abs Collection gives you the opportunity to train according to your mood. Pick a workout that best reflects how you feel, choose your level in the number of reps and then go flat out. Use the recovery time between sets to help you recharge. Done as a regular pattern in your workout week the HIIT training you put in will help improve speed, strength and endurance. Plus it will change the way you feel inside.