In the fourth installment of his TRX Suspension Trainer series, Brian takes his last exercise, the 45 Degree Mountain Climber, to another level, adding a BOSU to enhance scapular stability and core activation and improve balance.

    See 'RelatedResources' below for past Functionally Fits (including the TRX miniseries) andother exercises and training tips.

     Begin with both feet suspended in the TRX, knees on the ground and the BOSU flat side up. Initially, it is best to position the feet beneath the anchor point. Maintain a firm grip on the BOSU, with both hands on the outer edges of the BOSU. In this exercise, it is acceptable to actively protract the shoulder blades to better activate the serratus anterior muscle, since a primary goal is to improve scapular stability. 
     Additionally, I recommend keeping the elbows slightly bent to improve shoulder stability with the exercise. Once you are ready, raise the knees off the ground and move into a push-up type position, keeping the body straight. Next, bring one knee up, pause and lower down. Repeat on the other side. Perform 1-3 sets of 10-15 repetitions on each leg, while keeping a neutral spine and the BOSU level at all times.

    This is a more advanced version of the traditional TRX suspended mountain climber. I like adding in the BOSU (when appropriate) to enhance scapular stability and core activation through the natural perturbation the BOSU imposes on the body, as well as further challenge clients to resist loss of balance in the kinetic chain.

    This exercise is intended to improve upper body/core strength and stabilization. More importantly, the entire kinetic chain must work synergistically to maintain a neutral position as the TRX and BOSU together will create multi-planar perturbations. I suggest spotting the client by kneeling near the BOSU to prevent a sudden loss of balance, and then subtly correct or steady the BOSU until he/she demonstrates proper form.

    This exercise is suitable for advanced clients and athletes looking to improve core strength and shoulder stability. Mastering the BOSU clock (see my prior column on this exercise) is recommended to ensure the client can adequately control the BOSU in a similar position.

    This exercise requires a certain prerequisite amount of upper body strength, body control and understanding and/or familiarity with the TRX to be successful. Clients should master the 45 degree mountain climber and traditional (hands on the floor) suspended TRX mountain climber prior to even attempting this exercise.

    Brian Schiff, PT, CSCS ( is a licensed physical therapist, respected author and fitness professional. He became a Certified Strength and Conditioning Specialist (CSCS) in 1998. In 2000, he opened his own personal training and sport-specific conditioning facility, Fitness Edge, in Dublin, Ohio. Brian has presented at several professional conferences and seminars on injury prevention and sport-specific training.