Fierce45 Denver
high intensity | low impact | intentional movement



Center Core is meant for mid-line core engagement and each exercise is done for at least 60 seconds with 1 yellow spring (2 yellows for beginners).  All moves except Inchworm + Kneeling Crunch can be done on all directions of the machine.

Core Stabilizing moves

Core stabilization moves use the arms/legs as movers and serve to stabilize mid line of the body. They are typically full-body moves and increase the heart rate more than core crunch exercises. 


Body Position – Hands front plant form, knees line 1, open carriage, drop hips to modified plank position, press carriage back from shoulders and arms keeping hips stable; knees together, shins and ankles down on carriage

Movement –Sending carriage out and back from the shoulders, stopping before shoulders are over wrists

Muscles – Core stabilizer; lifting away from core

 Range of Motion – Hips low in modified plank position, head in line with spine; look out rather than down. Wider the carriage back from the platform the more intense the exercise; use muscle engagement rather than momentum to close the carriage, range of motion comes from shoulders.

Variations (harder)-

  • Range or angle: slower movement, press carriage out further, or knees to line 2
  • Carriage/ Back platform/ Back carriage
  • Plank Hero: toes on red line 1 (high plank position), same movement.

Modifications (easier)

  • Reduce range of motion
  • Forearms down- basically SAW (wrist injury)
  • Add a yellow spring (2 yellows total)

General Notes – Watch for: crossing ankles, overextending in shoulders, hips raised over shoulders (table top position), displacing ribcage and sitting in lower back


flying tabletop

Body Position – Hands to the front handle bars, toes to line 1, back is in table top position, high on tiptoes,

Movement – Start from extended plank, bend knees squeeze inner thighs together, carriage moves back 4 to 6 inches, shift shoulders slightly behind wrists, spine stayslong in table top position.   

Muscles – Core/lower core, inner thighs engaged

Range of Motion – Knees bend to under hips and extend back out to neutral spine plank.


  • Range or angle: shoulders shift behind wrists, handle bars in 4th position.
  • Back Flying Tabletop: same as Flying Tabletop but on the back facing the back with toes under the carriage strap, toes are stacked over the wrists


  • Shorter range of motion, handle bars turned in

General Notes – watch for: legs straightening completely, hips dropping, weight in legs rather than upper body.


Body Position – Hands to outside of front platform, shoulders over wrists, toes at line 1, back to high plank position, bend at knees until in line with hips, keep hips in line with shoulders--table top position, shoulders stacked over wrists full time

Movement – Start from high plank, carriage draws in by bending knees until knees are under hips (tabletop position) Extend back out to a high plank.

Muscles – Core stabilizer, quads are engaged, hip flexors relaxed, lower abdominals targeted

Range of Motion – Knees bend until they are under the hips for full range. Movement comes from the core and hips and upper body stays stable.

Variations –

  • Range or angle: Toes to line 2; take shoulders behind wrists at slight angle.
  • ·Add a pushup
  • Carriage/ Back platform/ Back carriage
  • Walking- Knee pulses in with toes lifting and alternate

Modifications –

  • Movement done on knees in a modified plank.

 General Notes – Watch for: hips higher than shoulders, knees coming in too close to chest, when legs are squeezed together increases engagement in lower core; shifting weight back into heels. Stress table top position of low back and low core engagement.


reverse pike

Body Position – Face the back on the front of the machine, hands on front handle bars, toes to creases of the carriage, arms and legs are straight. keep straight arms & straight legs

Movement – Hips start in line with wrists, lift hips up and back and return to starting position.

Muscles – Core, arms, hips, inner thighs

Range of Motion –  Hips do not pass wrists, lift as high as possible for full range or only a few inches for modification.

Variations –

  • Range or angle: hold hips back and up
  • Add tricep dips
  • Back Reverse Pike: back of the machine, facing the front, hands to back handle bars, toes under the carriage Strap. All other key ideas apply.

Modifications –  

  • Limit range of motion

General Notes – Watch that hips stop in line with the wrists on way down, avoid sinking in shoulders and wrists, press down into the handle bars and pull up from core.


Body Position – High plank position, hands on front platform, toes to line 1,

Movement – Start in high plank, lift hips up using transverse abdominals. Keep heels high and legs straight, gaze draws to ankles or inner thighs.  Lower back to plank starting position.

Muscles – Hips and core

Range of Motion – Lift hips up to ceiling, back to high plank position for full range. Hips can lift a few inches only if needed.


  • Range or angle: Feet can move to line 2, hips and heels lift higher for more intensity.
  • Carriage/ Back platform/ Back carriage
  • Flying Pike-to-Plank: Same as Plank to Pike but on the back facing the back with toes under the carriage strap and hands on the BACK HANDLE BARS, shoulders are stacked over the wrists.

Modifications –

  • Limit range of motion to hips lifting a few inches or hold high plank.
  • Modify to bear or wheelbarrow.
  • Forearms (wrist injury)

 General Notes – Legs straight, drop head to look back at toes when piked and keep ears in line with shoulders from plank position; forearms better for wrist issues.




Body Position – Modified plank position, hands to front platform, knees to line 1,

Movement – From modified plank, elbows bend under shoulders towards platform as carriage moves back. Hips stay stable, only upper body moves carriage.

 Muscles – Core, triceps

Range of motion – Pushing from forearm to straight arm while body is in wheel barrow is full range.


  • Hover elbows rather than landing down on platform.
  • Carriage/ Back platform
  • Plank Glider: same as Cobra but toes at red line one, high plank position. 

Modifications –  

  • Hero
  • One arm at a time to lift and lower.

General Notes – Avoid momentum, watch for dropping down to forearms – use of muscular engagement to release down, watch for dipping in lumbar spine, keep rib cage pulling together.

Core Crunch Moves

Core crunch moves use spinal flexion and extension to target the center core region of the body. 

fierce Crunch

Body Position – Sit on back platform facing the front with feet under the carriage strap. Hands cross chest, lengthened out, or interlace behind head. 

Movement – From a “boat” position, feet lengthen towards front of room and torso lowers towards 45 degrees. Movement comes from core rather than legs/hip flexors. 

Muscles – Core, abdominals 

Range of Motion – Keep torso at an angle at all times, do not sit whole way up. Keep shoulders behind hips to keep core engagement. 

Variations – 

  • Stay hinged back at the waste in upper body, 
  • 2 yellow springs

Modifications – 

  • Hands to back handle bars or behind knees for support.
  • 0 yellow springs
  • Block between thighs for hip flexor disengagement

General Notes – Keep shoulders back at about 45 degree angle, if shoulders stack over hips core disengages, keep chin lifted off chest, relax hip flexors

floor strap CRUNCH

Body position – Same set up as Super Crunch, but, feet under floor strap, hands behind the head, lengthened out, or across chest.

Movement – From extended boat position, hinge back from waist, sit up halfway about 45-degree angle, chin off chest.. Upper body moves, low body stays stable.

Muscles – Core, abdominals 

Range of Motion – Similar to Fierce crunch, do not sit the whole way up. Keep shoulders behind hips to keep core engagement.

Variations (harder) – Go back further and sit up less

Modifications (easier) – Smaller range of motion, hands to back handle bar for support

General Notes – Maintain length in spine/spine straight, chin off of chest, relax hip flexors. *Can also teach with person seated on edge of carriage facing the back of the room, feet under floor strap if makes sense for faster transition.


Body position – Knees on back platform facing the front, forearms on the carriage toward line 3 or elbows against carriage strap. Hips stay directly above the knees. 

Movement – Hips stay over knees as carriage pulls in towards low body. Low, mid, and upper back curl in to pull carriage in, rather than using knees or legs. Shoulders stay over elbows and upper back rounds.  

Muscles – Core, Triceps

Range of motion – Torso extends long to a modified plank and pulls in so hips are over knees for full range.  Motion can modify to a few inches if needed. 

Variations (harder) –  

  • Saw:  forearms extend out long and then slowly pull elbows under shoulders before rounding the back. 
  • Back carriage

Modifications (easier) – 

  • Shorter range of motion.  
  • New or less-strong students only send to the front of the machine.

General notes – Watch for: pulling with knees, hips moving over knees, gripping of platform, dipping in low back on extension. 

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super hero

Body Position – On the front of the machine, facing the front. Place hands on the handlebars with knees on the carriage at line 2 and feet in the eyelets. Carriage pushes back until arms are straight and spine is in line with shoulders. 

Movement – With arms extended fully, knees draw in until under the hips and then push back out to extension. Crown of head stays in line with shoulders, hips, and knees. Movement comes from the core and low body (below the waist) stays stable when knees draw in.


Muscles -  Quads, glutes, abdominals, chest, tricep, shoulders, lats

Range of Motion – Arms stay straight, chest stays stable as legs hinge at waist moving back to lengthen and then resist back in under line of hips. 

Variation -  

  • Hands move further down handle bar
  • Elevated: *same as super Hero, but knees float off carriage rather than resting at line 2. 

Modification (easier) – Limit range of motion, move hands further up on handlebars  

General Notes – Watch for chest rising above line of wrists. Keep arms straight and chest low as lower body moves and presses carriage out.