TRX — The Science of Suspension Training

A special ops team member pushes himself during a TRX workout.
Cyle Brewer, a member of the Copperas Cove Special Weapons and Tactics team, pushes himself during the TRX training circuit at the Applied Functional Fitness Center at Fort Hood, Texas, Dec. 16, 2015. (Sgt. Juana M. Nesbitt/U.S. Army photo)

Evidence that something works is what we all look for before we make a purchase -- especially a major purchase. With everything from the cars we drive, to the food we eat, to the homes we live in, we like to make sure when we buy something that it works, is good for us and can help us reach our short- and long-term goals.

I have been using the TRX since its development nearly 10 years ago and have noticed significant core strength gains as well as extremity increases in muscle stamina and strength. However, after years of the TRX Suspension Training System being on the market, here is what the exercise scientists are saying:

TRX suspension training: Stable vs. unstable

The revolutionary training applications of adding instability to your workout exercise choices has been proven to stimulate core musculature. Although this study is testing a variety of skills, it found that the TRX outperformed many of the stable exercises with regard to core muscles (abdominals, obliques, lower back) and was found to be comparable to stable exercises on other muscle groups (chest, shoulders, lats, shoulder girdle, biceps, triceps). (Stable vs. Unstable)

TRX muscle activation studies

Muscle activation studies are popular within the exercise science world and have classified certain exercises better than others by measuring the electric impulses on a particular muscle or group of muscles during a specific movement or exercise. The use of electromyography (EMG) has been instrumental in detecting activation levels and muscle recruitment order in a given movement.

However, just because the activation of a muscle is increased, it does not mean that will equate to given adaptations like strength, power, muscle stamina, flexibility, etc. The EMG reliability in fine-motor movements is limited in scope, but it is reliable in major muscle group movements.

The TRX was tested using EMG and was found to activate the muscles of the core and torso, and it offers a variety of training options to achieve these results. The research shows that muscles are more active compared to the regular calisthenics or weight-training options -- especially the stabilizing muscles of the core.

However, if your goals are higher-level strength or cardiovascular training, traditional weight training and cardio events are superior. But if you do not have elite strength/cardiovascular training goals, the TRX is effective in developing strength and cardio gains when creative with the device.

TRX: Fitness in a Bag

    TRX core exercises tested

    One reason why I started adding the TRX to my exercises was specifically the challenging planking movements and varieties it offered. This study measured muscle activation in the rectus abdominis, external oblique, rectus femoris and serratus anterior muscles, using the EMG like the study above.

    Compared to the normal plank pose, which is a useful exercise and should not be dropped, the TRX muscle activation was greater using a variety of methods than the normal plank pose with stable feet and arms. By placing the arms in the TRX and having feet stable, feet in the TRX and having the arms stable, and by using two TRX devices to suspend both the arms and the feet, the EMG showed a greater use in all muscles tested.

    Your first plank pose in the TRX will tell you that in about 10 seconds. My favorite core TRX exercises are the atomic push-up and the TRX rollout; for me, these two make all other abdominal exercises second- or third-place options.

    TRX's use in aging populations

    feasibility study on a group of 11 60+ aged men and women living in a retirement community was conducted recently. Although the study showed that a training program using the TRX is feasible for use with the aging population, it is a challenging course.

    Follow-up studies can be developed to show growth in strength, muscle mass, core strength, balance and mobility. From the study: "All participants noted positive effects. In comparison to gait and balance improvements, strength gains were mostly reported. This might be due to the program that primarily focuses on strength. Slight balance improvements can be explained by increased core muscle activation and advanced balance abilities during sling exercises."

    A relatively low number of participants stated they likely will continue using the TRX after the study. Suspension training is difficult and is an acquired taste to even the most avid of exercisers.

    A thorough exercise study on the TRX

    The American Council on Exercise did a thorough study, taking in a number of baseline measurements from health data as well as performance data. Body composition (fat loss/muscle gain) and cardiovascular health were improved by adding the TRX into a 60-minute workout routine three days a week for six weeks. This study included the results of full-body workout circuits that included upper-body push and pull muscle groups, core, lower-body exercises with the TRX and added a variety of cardiovascular exercises (running, speed, agility, other non-impact cardio options).

    There is a reason why I replaced a 400-pound weight set, bench and squat rack with the TRX. It works. Plus, as I age, though I still like to lift, I am not lifting as heavy as I did in college 25 years ago. I have found that keeping a barbell, kettlebell, a pullup bar and a TRX was all I needed to build above-average strength, power, muscle stamina and a stronger back and core, similar to what I had when I was 25 years old.

    Standby for results of using the TRX in place of heavy weightlifting cycles during the winter powerlifting cycle of my periodization program. The goal is to stay lean, stay strong and not have to go on a diet when I run again in the spring.

    Referenced studies list:

    Stable vs. Unstable: Analysis of pushing exercises: Muscle activity and spine load while contrasting techniques on stable surfaces with a labile suspension strap training system.

    Evidence Based Practice: Suspension training (EMG test)

    The Effect of Using TRX testing Muscle Activation During Plank Pose: Core test

    TRX Testing In Older Adult Population

    ACE Sponsored Research on the TRX: American Council on Exercise

    TRX Training Effects in Untrained Men: Effects of instability versus traditional resistance training on strength, power and velocity in untrained men.

    Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to

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