February 28, 2023

X3 Bar vs Undersun Fitness Bands

In a detailed comparison of Undersun Fitness resistance bands versus the X3 bar system, we found X3 outperformed Undersun in every area. From price and durability to physical challenge and community support, X3 delivers a greater overall return on investment.

Read on to find out why.

What Online Reviews Reveal

Young woman training with resistance bands

When compiling online reviews and forums, we discovered that Undersun resistance band users overwhelmingly utilize X3 training videos to improve upon the function of the Undersun Fitness system. This speaks volumes about the universal value and quality of the X3 product and its training protocol.

Using free video footage and ideas generated by the X3 community to boost the effectiveness of a lower-quality product is understandable when budget is a real constraint. However, there are some differences between the two systems that programming alone cannot correct.

X3 costs more upfront, but you get what you pay for at the end of the day. From product to programming, X3 bar significantly outperforms Undersun bands. We explore the apparent differences between the two popular resistance band systems.

Undersun Fitness vs. X3: What Reviewers Say

Young Man stretching against a blue wall after a workout

Customer Service

Undersun Fitness Bands come with a 90-day warranty, and users leave positive feedback regarding the company’s willingness to replace broken parts within that time frame. That’s good news, but it could also be a red flag.

A few reviewers do mention their bands have ripped or snapped within the first couple of months of use, which is a considerable safety concern.

If your bands leave you fearful they could tear at any moment, it will be hard to feel confident during your workout. We know that to build muscle through variable resistance safely, we must lift heavy, and we must lift to fatigue. Therefore, your resistance bands have to be willing to withstand a considerable load repetitively.

The Bands

Like the standard X3 bands, Undersun Fitness bands are made from all-natural latex. The company’s new Elite Resistance Bands Set features 2-ply bands, which allow users to “avoid breakage with our 2-ply design.”

As a side note, the company does donate proceeds of every Elite Bands sale to an organization that supports military families, which is highly commendable. Both companies offer military discounts for those who qualify.

Back to the bands. X3 resistance bands are known for their longevity. Many users have been stretching their X3 bands for over four years without issues.

When it comes to building strength, max resistance is another matter. Undersun offers five levels of resistance bands labeled as light, medium, heavy, and so on. The strength capacities of their heavy resistance bands are listed on the website.

The X3 Elite band is capable of generating over 600 pounds of resistance. So if you’re already strong and want to get stronger, you can rest assured that X3 bands will get the job done.

The new X3 Performance Bands, available only to X3 purchasers, are engineered from ParaForce Rubber™. These bands are the most durable and powerful bands on the market today.

Undersun Fitness Programming

Undersun’s fitness programming is online-dependent. Their TA2 program spans the areas of fitness and nutrition. Several reviewers complain they’ve had difficulty accessing the online portal once their band system arrived. This means no access to program modules and videos.

Like X3, Undersun promotes variable resistance training. However, the company does offer gym-based workouts featuring weighted movements. As Dr. Jaquish has touched on at length, weights overload joints and underload muscle.

While difficulty accessing the app can be a minor convenience, the more important question is, are the bands and programming effective at building muscle and reducing body fat percentage?

Beginners vs. Builders

Man getting ready to exercise

Undersun offers different programs for muscle building versus fat burning. Other than forcing two purchases, it’s curious as to why. Building muscle burns fat. Doing two different workouts for two separate results is a waste of time.

In any case, users are generally pleased with the Undersun program’s foundation. But as the workouts progress to anchored exercises, many comment the program becomes both dangerous and too easy.

Using lighter resistance bands may benefit those new to the movement, rehabbing from injuries, or with limited strength and mobility. But it seems as users progress, Undersun fails to deliver.

Undersun bands and the accompanying door anchor aren’t strong enough to resist breakage and safely support the repetitive movement.

If you’re looking to build muscle, burn fat, and progress with your training in an efficient, timely manner, X3 is the better option.

Not only are the bands strong enough to support powerful forces without overstretching, but the repeatable, 12-week programming targets both muscle growth and fat loss in only 10 minutes per day. The science doesn’t lie: X3 shines in its research-backed program.

Wasting Time

Some people enjoy spending an hour or more on fitness daily. For these individuals, the X3 will require an adjustment phase. The program, when followed correctly, requires at most 20 minutes per day. Why? X3 maximally taxes muscles within just one exercise set, freeing you from boring, 60-minute routines.

Undersun’s programming is more typical of standard resistance band programs, which require a similar time investment to traditional free-weight or cardio workouts.

If you enjoy spending time on fitness, that’s great. But if results are more important to you than the time spent getting there, X3 is the better choice.


As we’ve mentioned, Undersun users are generally underwhelmed by the fitness system’s ability to anchor safely. Not only that, but the bands lack strength when it comes to total-body compound exercises like deadlifts, squats, and bent-over rows.

The X3 ground plate and bar are game-changers. Without a bar or ground plate, resistance bands of any strength will be limited to what the ankle and wrist joints can safely support.

Undersun attempts to overcome this obstacle by recommending the use of gloves, sold separately. You can awkwardly grab over-stretched bands with a set of gloves, or you could grip an Olympic barbell bar, just like you’re used to. For us, the latter makes strength training far more effective and comfortable.

Anchors are a key component of the Undersun Fitness resistance band package. Unfortunately, the anchor’s stability remains in question—many reviewers mention how dangerous and difficult it is to navigate the door anchor and the associated exercises.

So, again, if you’re worried about safety or a band recoiling in your face, how can you possibly exert yourself with confidence?

Safety First

Weak resistance bands and the lack of a supportive grounding plate and bar make Undersun dangerous for anyone attempting heavy or repetitive lifts.

Users complain they cannot securely complete the program’s anchored exercises because the door anchor is unstable. This is a significant issue.

X3 Bar was designed in a lab by an engineer Ph.D. whose primary goal was to create a safe, productive, and challenging training program. Its bands, steel plate grounding platform, and program requirements are designed to keep joints safe from injury while maximally loading muscles.

The intense forethought and ingenious design of the X3 bar makes it outshine other band systems and traditional weight training.

Neither weights nor poorly designed resistance band systems target the muscle effectively without taxing bones and joints. However, with the X3 system, training injuries are a thing of the past.

If Undersun can’t claim the system is safe, nothing else matters at the end of the day.


The sticker price of a set of Undersun bands comes in at less than $100, including five bands, a door anchor, and limited free trial access to an app-based training program.

Gloves are sold separately yet mentioned in nearly every review as necessary for hand-friendly use. As one user put it, “you MUST wear gloves when you work out. The bands will murder your hands.”

Additional app-based training and nutrition programs are also sold separately.

While Undersun reviewers comment they enjoy the program’s leading trainer, they seem to rely heavily on free YouTube videos and even X3 users to provide them with more well-rounded programming content.

This avoids the additional programming expense and provides more band-only exercises, which avoids the use of the risky door anchor.

Undersun Bands Pros and Cons

Woman doing a squat with a resistance band
Woman doing a squat with a resistance band

Overall, when looking at the primary differences between X3 and Undersun, the only pro we could find for the latter was the price. Have you heard the old adage, pay now or pay later? The upfront savings mean nothing if the product doesn’t last or produce visible results.


  • Low initial price compared to X3
  • Reasonable customer support when replacements are needed


  • Need gloves and accessories to avoid injury (sold separately)
  • Includes standard-quality bands that can tear or rip
  • Low-quality door anchor poses a danger to eyes and hands
  • Users turn to X3 videos (not Undersun programming) in an attempt to make workouts more challenging
  • Internal system issues include trouble accessing online programming
  • Training and nutrition programs are sold separately

X3 Outshines Undersun

X3 Bar Resistance System

The virtues of X3 training are hard to overemphasize, as the system delivers when it comes to challenge, efficiency, time spent, durability, community, and return on investment.

Those complaining about X3 bar sticker shock may want to re-examine their long-term commitment to fitness results. Or consider financing X3 for as little as $50 per month.

Any price point comparison would find gym memberships, training packages, and home systems cost thousands yet fail to deliver X3’s proven results. Moreover, X3 has a money-back guarantee for doubters who can’t believe something so simple actually works.

Why X3?

Many facets of the X3 training system set it far ahead of any competition.

Time Well Spent

Thanks to variable resistance and strong-enough bands to support exhaustion, the X3 bar provides targeted fatigue to muscles in much less time than traditional free weights or lighter bands do.

Only one set is required to effectively tax the target muscle group by optimizing the loading principle with continuous variable resistance. The recommended circuit should take approximately 10-15 minutes daily to complete.

The X3 stimulates muscle growth rather than annihilating muscle fibers and joint capsules, meaning you can work out daily as you get fitter.

The World’s Best Resistance Bands

In comparison to competitor band systems, there’s no contest. Other bands don’t match loading principles and therefore require up to four times as much energy input to achieve similar levels of muscular fatigue.

Even then, the stimulus is not comparable: hormones require fast-twitch activation, and endurance activity does not build muscle like the X3 band. You need strong bands. More time spent with lighter bands or doubling-over insufficiently strong bands just isn’t the same.

Muscles grow when muscles are worked to fatigue. Diminishing sets, in which movements are continued way after this fatigue begins, further recruit muscle fibers for greater gains.

X3, armed with its steel alloy bar and stabilizing ground plate, comprises the only system capable of withstanding elite-level resistance and delivering exhaustion in a single set.

A Supportive Community

One final benefit offered by the legacy of the X3 system over its competition is the engaged online user support group. Tens of thousands of happy X3 converts provide encouragement, testimonials, and education for new users, adding accountability, solidarity, and community.

Many users acknowledge the high value of this virtual space. The online community helps them stay focused on their goals, learn from others, and find support in shared personal growth experiences. This is true for people who enjoy access to groups for both men and women.

Meanwhile, what are Undersun users doing? Sharing what they’ve learned from X3 science and programming in their online forums…

Final Wrap

Overall, if you’re looking for an introduction to resistance bands and you want to learn the movements, but go light, buy Undersun. If your goals include building strength and losing weight, invest in safe and effective equipment with the X3.

X3 shines in its programming, safety record, durability, accessibility for a wide range of fitness levels, and scientifically proven efficacy. X3 provides an excellent customer experience through collaborative community forums and online groups.

With X3, you train with greater force to trigger Greater Gains

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