Cardio Kickboxing Warnings

We learn as time passes. When aerobics first started years ago we were doing dangerous stuff until we learned more. Cardio Kickboxing is at that stage of development now. Don't confuse Cardio Kickboxing with Kickboxing. Both Boxer's and Kickboxer's goals are to win in a fight regardless of the impact on their bodies. That's why you don't see old boxers still in the ring. Boxers and Kickboxers sustain injuries and eventually are no longer able to train. Not all of their injuries are delivered by their opponents. Some are self inflicted over time.

In aerobics, our goals are the opposite of the pugilist. We do this with a priority to take care of our bodies not win a fight or tournament. As such, there are moves that are natural to the fighter that we in aerobics should not do for two reasons:

  1. We intend to do aerobics well into our old age.
  2. Our classes are mostly considered "General Population".

We have been concerned with reports of joint injuries sustained while watching commercial kickboxing videos and from people attending classes. We are going to get more active concerning Cardio Kickboxing safety. Too many injuries and too wide spread. We have seen some widespread variations in the training of Kickboxing Group Fitness Instructors. Some of the routines being taught come from kickboxing instructor turned aerobic instructors and some from Group Fitness Instructors turned kickboxing Group Fitness Instructor. Cardio Kickboxing is not Martial Arts training. It is an adjunct to it. It can develop the self-confidence, muscle coordination, technique and flexibility required to begin Martial Arts training. Don't confuse the two.

Gyms need to be concerned to avoid potential long term liability as well as individual instructors. It is surprising to see some very reputable certification organizations teaching Cardio Kickboxing concepts from a martial artist's perspective.

Causes of Injury:
  1. Hyper-extension of the elbows and knees.

  2. Ballistic, high power punches and kicks.

  3. Duck and jab moves that over extend and torque the knee (worst).

  4. Too much high impact and for too long of a period. Alternate high and low impact moves throughout the class.

  5. Insufficient warm-up period and stretching. Leg stretches should be done every 15 to 20 minutes during class.

  6. Side kicks without rotating the hip forward causes lateral pressure on the knee due to gravity.

  7. Side kicks while rotating the toes down only, torque the knee, The hip needs to be rotated forward which naturally points the toes down and takes the lateral pressure off the knee.

  8. Not unloading the knee when turning causes torqueing and strains the ACL ligaments.

IFA will continue to investigate this concern and report any additional findings here on this page. You can help. If you have a recommendation concerning Cardio Kickboxing or any other type of aerobics, send it to us. We will review it and include it on this page if appropriate.


There's a tremendous amount of confusion over this move. Understandably so. At IFA, our background is martial arts, aerobics instruction and personal training. Most outfits are relying on the input from martial arts people only or aerobics people only.

The proper form for this move from the martial arts perspective is knee drawn in towards body and then extended with toes down, hip rotated forward, and the opposite foot pointed away from kick. The problem stems from the toes down detail. In martial arts, if the toes are pointed up the toes risk getting broken by an opponents block. In addition, the point of contact should be the blade of the foot. Toes pointed up cannot line up the blade of the foot properly. Also when the toes are not pointed down the knee is perpendicular to the floor placing the weight of the lower leg directly along the lateral portion of the knee. The knee does not fair well under lateral stresses. Toes pointed down switch the weight bearing action of the knee to a position off the lateral line.

If the hip is not rotated forward and toes are forced down, then the knee is in a torqued position. Hip rotation is not a problem for even general population. The problem comes from the pitch of the music. Even at step speeds (122-128 bpm) this move can become a ballistic move and thereby compound the torqued knee condition.

So what's the solution? The answers lies in the realization that Cardio Kickboxing is NOT Kickboxing or even general martial arts. It is aerobics. Just like side-straddle is not horse-back riding.

The solution is to reduce the pitch of music to step speeds for the entire Kickboxing class as a start. For this move, high side kicks are not recommended. Strike an imaginary target at knee level and not higher. This provides a low ballistic component to the move. Rotation of the hip can be perfomed with less of an extreme. Hip rotation, which is a natural move, will prevent knee torque and ACL stress when pointing toes down, unless it is done in the martial arts sense which is an extreme move. The body is slightly leaned to the opposite direction of the kick. A front, same side low block can be incorporated with the kick.

Another move is the push kick which is done the same way with the exception that the leg is extended out at a diagonal with toes up. Strike point is the ball of the foot. This move is easier to do and can be used for older population classes.


Some organizations are recommending that the shoulder not be raised during the jab punch. The shoulder naturally raises up when the arm is extended forward unless it is forced into a level position. Don't artificially raise the shoulder. This creates an unstable platform at the shoulder for striking a target. Richard Hoehn, Martial Arts Instructor.

When executing the jabs, the elbow should come from the hip straight up keeping the elbow down until the rotation of the fist at the end of your (85%) extension. The arm should then be returned to the original position with focus on the flexion of the Bicep as you come back to your guarded position...It's an Isometric exercise of the Bicep. The jab form illustrated in the video on this website is an example of bad form which uses more of the triceps which can lead to possible injury from Hyperextension. Additionally, rotating the elbow outward from the body too early, can cause rotator injury ... not to mention losing some of the intensity. Jim Reynolds, Fitness Instructor.

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