Sledgehammers are commonly used to improve total body strength and power, as well as increase conditioning. In this column, I will discuss how to use the MostFit Core Hammer as an alternative to a traditional sledgehammer to achieve physical gains. In my previous column, I discussed how to increase trunk stability and strength using this training tool. Prior to engaging in this advanced exercise, one should be able to demonstrate proficiency in the torso rotational lunge and handling of the core hammer.

Execution: Initially, I suggest using a soft plyobox (12 inches) to reduce the vibration and reactive force upon impact that is transferred to the hands/wrist. It also limits the force production and velocity of the movement as the hammer is not traveling as far. This is desired for a novice user or someone with less upper body strength.

Position the top (dominant) hand at the top of the MostFit Core Hammer. Grasp the handle with the other hand and position it at least 6-12 inches above the bottom of the handle to reduce the lever arm at first. Next, perform a slower controlled slam into the soft plyobox at about 50% of maximum intensity. Repeat 3-5 sub maximal repetitions to ensure proper form and become comfortable sliding the top hand down and then repositioning prior to the next repetition.

Once the client is fully proficient and comfortable with the technique, perform 10-15 repetitions or 30 seconds of work. Depending on the strength and coordination in the non-dominant side, it may be best to consistently use the dominant hand on top of the MostFit Core Hammer at all times. This method will be fine, unless the goal is to develop symmetrical strength and power on both sides. In this case, switch the hands on each set.


1. Increase repetitions or time

2. Progress from 8# to 12# core hammer

3. Decrease rest time between sets

4. Progressively lower the plyobox height until you reach the floor. With that said, I recommend avoiding concrete floors as the stress at impact will be higher on the joints since there is no give. Preferably, seek out a cushioned (rubberized) floor or simply use a 3 inch soft plyobox for advanced clientele.

Application: This exercise aims to improve upper body strength and power. In reality, it will facilitate total body conditioning and improve anaerobic conditioning. Keep in mind that proper form and technique is essential in order to avoid injury. Choose the weight of the hammer accordingly, while modifying the other variables to deliver the right intensity. The core hammer allows for both individual and group training and is very portable as well. This exercise can be used as part of a circuit-based training approach or stand alone as power/metabolic conditioning.


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