An Australian study of women recently 

unearthed the following: Women who 

followed a 20-minute HIIT program con-

sisting of eight-second sprints followed 

by 12 seconds of rest lost an impressive 

six times more body fat than a group that 

followed a 40-minute cardio program 

performed at a constant intensity of 60 

percent maximum heart rate (MHR).

6x More  

Fat Loss

• 

SLOW TWITCH

• 

FAST TWITCH

• 

SUPER FAST TWITCH

But while traditional cardio works either fast 

or slow twitch fibers, HIIT increases the 

body’s production of hGH by working super 

fast twitch muscle fiber, causing your body 

to produce more hGH.

Don’t be afraid to push yourself on HIIT 

cardio days since this will be your only 

focus. It’s why I don’t have you working out 

with weights on the same days. And if you 

walk away from anything using this workout, 

(besides results, of course), you may be 

convinced that separating cardio from 

resistance training days makes good sense 

while speeding up fat oxidation.

A study by East Tennessee State Uni-

versity found that if subjects followed an 

eight-week HIIT program, they dropped 

2 percent body fat over the course of 

those two months. Others following tradi-

tional methods of low-intensity cardio over 

longer durations, lost none.

2% Body Fat 

 Reduction In Just 8 Weeks:

HERE’S ANOTHER EXAMPLE:

Treadmill on Incline -

» 15 seconds sprint » 10 seconds rest

» 10 seconds sprint » 5 seconds rest

» 20 seconds sprint » 15 seconds rest

» 30 seconds sprint » 20 seconds rest

Repeat 12 to 15 times = 

20 minutes (treadmill or stationary cycle)

CARDIO

[C]

20  PRIMAL MUSCLE  TRAINING GUIDE