04/01/2014 08:32 am ET Updated Dec 06, 2017

30 Days of High-Intensity Interval Training (HIIT)

Our bodies are designed to optimize at whatever level of training we push at them. This is a survival mechanism intended to give us an evolutionary advantage in Paleolithic times. In the modern age it just means that the workout we have scheduled to do on a busy day delivers diminishing returns as our bodies find ways to burn fewer calories and perform with less effort.

The workaround to this is to constantly vary our training routines but that in itself can be tiring and it poses a further mental obstacle to simply doing any training at all. This is where high-intensity interval training (HIIT) workouts come in. Designed to be high-burn, constant-challenge sessions, a HIIT workout is the simplest way to shock the body out of its physical complacency and force it to work harder than it has ever done before.

There are several benefits to this. First, we burn up more calories than ever. Faced with the demands made by a high-intensity interval training session the body hasn't got a lot of time to adapt and optimize what it does. The incremental inefficiencies that this produces simply up the calorie burn in the session.

Second, it boosts your metabolic rate. For a short while after the HIIT workout you simply burn more even when at rest. Third, it enhances performance. Challenged by the intense physical routines the body's muscles learn to perform at a higher rate. Simply put, after an HIIT session (or two) you can go back to your normal physical training and you will find it easier.

The HIIT workouts are the fastest way to look lean and mean when the weather demands we get about wearing fewer clothes. The real benefits, however, are mental. Getting through a HIIT session requires mental toughness. No matter how fit you are a HIIT workout demands 100 percent of you, all the time. That makes you focus and toughen up. In this one I have also added ab routines for that extra tang.

Try one of the routines right now -- all you need is 15 minutes and a timer:




You can download the complete 30 Days of HIIT program from here or start it online.

Need an online stopwatch? Here is one.