Fierce45 Denver
high intensity | low impact | intentional movement




 FIERCE HIIT exercises are each 20 seconds at high intensity accompanied by a 10 second active recovery exercise. Each sequence is done 8 times with a 1 minute rest for water and high fives before the next sequence. Moves should be demonstrated during the warm-up or the minute break between sets for maximization of time. 

HIIT training has been shown to improve: 

●      aerobic and anaerobic fitness blood pressure 

●      cardiovascular health 

●      insulin sensitivity (which helps the exercising muscles more readily use glucose for fuel to make energy)

●      cholesterol profiles 

●      abdominal fat and body weight while maintaining muscle mass.


FORMAT- Start with a two minute warm-up consisting of moves to prepare the body for the HIIT exercises (squats, jacks, etc). The warm-up is a great time to briefly talk about the format, show the exercises in the first two sets and talk about alignment. The warm-up is followed by 20 minutes of FIERCE HIIT exercises with a 2 minute break to get water, take off shoes and put on sticky socks to transition into 20 minutes of CORE and OBLIQUES on the Xformer. Intensity during the high intensity work interval should range ≥ 80% of your estimated maximal heart rate. As a good subjective indicator, the work interval should feel like you are exercising “hard” to “very hard”.

BALANCE -Be mindful of structuring your HIIT sets to work the same muscle groups. For example, you would group squat jumps and squat walks together (both low body); however you would not group squat jumps with inchworm (low body and upper body/core). Essentially it is working in BLOCKS as we do in a regular full body Fierce45 class. Also be mindful to balance the use of upper body with low body in your four sets of HIIT. Please refer to the sample classes below.

HOW- Follow the HIIT exercise (20 seconds) with an active recovery exercise (10 seconds) that targets the same muscle group(s). For example, squat jumps could be followed by a squat walk or squat with toe taps to target the glutes, hamstrings and quads. Please refer to the exercise portal for a full list of HIIT exercises and active recovery exercises with videos and detailed descriptions of each.

sample outline

Set 1                                                               Set 2

Cardio                                                            Cardio

Active Recovery                                            Active Recovery


Set 3                                                               Set 4

Cardio                                                            Cardio

Active Recovery                                            Active Recovery


Core                                                                Obliques

Plank to pike                                                   Carriage twisted plank to pike

Forearm plank crunch                                    Twisted kneeling crunch

Reverse Pike                                                  Twisted Fierce crunch