Wednesday, 24 July 2024

Inversion Tables

Ironman Gravity 4000 Inversion Table Review

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Also known as the Ironman 5402, the Ironman Gravity 4000 is currently the number one bestselling inversion table on Amazon, with over 1500 reviews.

But how does it compare with lower priced tables in the Gravity range, and does it really represent the best value for money?

In this review we’ll be taking a look at the design features, storage options, customer reviews, and assembly process to help you decide if this is really the best choice of inversion table for your own home gym.

Design features

The inversion range can be restricted to cater for different experience levels

Inversion tables offer a unique range of motion that places your body in a position you may not be used to if you haven’t tried this kind of exercise before.

But to reach the angles that provide the greatest health benefits, you’ll need to be confident that of staying well supported and secure throughout the inversion.

That’s why the Ironman 4000 has been designed with an extra-wide, tubular steel frame and fitted with tough rubber non-skid floor stabilizers to prevent any unwanted movement.

In fact, this model actually features one of the strongest frames in the industry, offering an impressive 350 lb weight capacity.

The exterior has also been covered with a scratch-resistant, powder-coated finish to reduce the risk of scratches, abrasions and rust.

To cater for different user heights, the adjustable boom section has a clearly marked list of settings for the back support, ranging from 4’10” to 6’6″.

It’s important to note that the same inversion range doesn’t need to apply to everyone.

Matching the range of motion to your experience level
If this is your first time using a product like this, you might want to limit the inversion to just a few degrees.

Although the full 180 degree range of motion is possible, the Gravity 4000 joins the earlier 3000 model in offering a choice of three starting positions via the pivot arms on either side.

The palm activated ratchet ankle locking system is an advantage over the spring loaded design of the Gravity 1000 and Gravity 3000 models, as it doesn’t require you to bend down as far to release the heel holders.

The 4000 model has also been fitted with a number of subtle safety features, including the double stitched vinyl side panels to protect your hands, and a nylon strap underneath to restrict the inversion angle.

When you combine the choice of three starting positions with the inversion limitations created by this nylon strap, you have an inversion table that’s incredibly stable, strong, and most importantly, safe.

Ironman Gravity 4000 Inversion Table

Ironman Gravity 4000 – Features Summary

  • Sturdy inversion table for reducing back stress and stimulating circulation
  • Tubular steel frame, memory-foam nylon backrest, and powder-coated finish
  • Tough rubber non-skid floor stabilizers
  • Inverts up to 180 degrees
  • Ergonomically molded ankle cushions
  • Folds for storage
  • Removable lumbar support pillow
  • Choice of three starting positions

Comfort and cushioning

The 4000 model is the only inversion table in the Gravity range to offer a lumbar pillow

Although inversion therapy sessions aren’t required to be particularly long, if you’re uncomfortable for even a few minutes at any inversion angle, it’s going to be remembered as a negative experience.

That’s why to help make sure every session is as comfortable as possible, the Ironman Gravity 4000 features a memory foam back rest.

When we were reviewing the earlier Gravity 1000 model, one of the complaints we noticed was that the material covering the foam would tear in a small number of cases.

You’ll be pleased to know that this particular model has replaced the nylon covering with a waterproof vinyl material, that’s also been double-stitched for increased durability.

Even the full length safety handles have been covered in a softer material to reduce the pressure placed on your hands when held.

One final important area in terms of comfort is the heel holders.

These feature ergonomically moulded cushioning to reduce the pressure placed on your feet and ankles when you move beyond parallel towards the full inversion.

This is also the only model to include a detachable lumbar pillow for improved lower back cushioning.

How frequently do you need inversion therapy sessions?

Ironman Gravity 4000 Inversion Table

This really depends on what you’re looking to achieve and how quickly you start seeing results.

For example, many people suffer from lower back pain and start using an inversion therapy table on a daily basis with good results.

In fact, we’ve read several reviews from customers who were able to use an inversion therapy table for a few months at this frequency, then dial it back to just once each month because they experienced such a reduction in chronic back pain and muscle stiffness.

In the owner’s manual for the Gravity 4000, Ironman actually advise two or three sessions per day depending on your current physical condition, with each session lasting no more than ten minutes.

They also encourage you to keep moving if your goal is to increase blood circulation, with stationary 180 degree inversion limited to just a few seconds at a time.

Note: There is some difference in opinion over what full inversion actually means. Some definitions say 180 degrees is upside down, while others refer to this as 90 degrees of inversion from the horizontal.

Providing you have the correct setting for your height selected on the back support, you should be able to start the inversion by simply raising your arms above your head.

This transfer of weight should be enough to get you close to horizontal, where you can start to use the safety handles to control the inversion angle.

Health benefits of the Gravity 4000

  • Uses gravity helps to straighten and elongate the spine, which results in more relaxed back muscles
  • Reduces the stress in the back by increasing the space between your ligament and vertebrae discs
  • Reduces chronic back pain, fatigue and muscle stiffness
  • Improves blood circulation
  • Increases body flexibility to improve athletic performance
  • Helps relieve lower back aches due to sitting or standing

Comparing the Ironman Gravity inversion tables

ModelGravity 1000Gravity 2000Gravity 4000
BackrestNylonVinyl Covered FoamVinyl Covered Foam
Lumbar SupportNoNoYes
Steel FrameStandardStandardHeavy-Duty
Weight Capacity300 lbs300 lbs350 lbs
Height AdjustmentUp to 6'6"Up to 6'6"Up to 6'6"
Ankle Locking SystemSpring LoadedSpring LoadedRatchet System
Product Weight46 lbs65 lbs75 lbs
Total Inversion Angle180 degrees180 degrees180 degrees

Ease of assembly and storage options

Assembly instructions feature a combination of diagrams and text for increased clarity of what's required

Whenever you buy a new piece of fitness equipment, you tend to think about the benefits that you’ll see once you start to actually use it, and not necessarily the assembly that comes before.

Fortunately Ironman have done a good job of pre-assembling the frame where possible, and providing a clears parts list in the user manual. You’ll also find all the tools you need (wrench and screw driver wrench) in the box.

The assembly instructions themselves are well written and split into a number of clear steps, with accompanying diagrams to help explain the process a little better.

Nothing particularly complicated here, but due to the increased frame weight compared to earlier models, you may find it useful having someone assist you with fitting the bed frame to the adjustable boom.

Because of how concise and clear the instructions are, and the fact that each part is clearly referenced along the way, it shouldn’t take much longer than 60 minutes to get this inversion table setup and ready to use.

Can the Gravity 4000 be used by more than one person?
If more than one person will be using the inversion table, there are a few things which may need to be changed each time.

The first is the height of the back support. This shouldn’t be too difficult as there’s a clearly marked height scale on the boom, and the back support is free to slide up and down the rail after removing a couple of pins.

The second is the choice of pivot arm setting. Again this shouldn’t take long, and you can actually just pull out on them to slide the pin to the hole that you need.

The final setting that may need to be changed if two people are using the table with different heights or different experience levels is the nylon strap.

Although it doesn’t take long to adjust, you don’t have the same clearly marked settings the way you do with the features we just mentioned. This can result in a bit of a trial and error approach, which can be a bit more time consuming unless you find a way to mark the strap.

Storage options

Although folding is an option, for the slimmest profile you need to separate the boom section from the double U-frame

As we mentioned in our reviews of the Gravity 3000 and Gravity 2000 models, although the frame can be folded, it doesn’t lie completely flat.

This reduces the amount of floor space required, but the close placement of the U-shaped frame sections in the folded position means that it isn’t free standing.

So you really have two options if you’re unable to keep the Gravity 4000 permanently setup.

Firstly, you can close the U-frames together and lean the table against a wall or solid surface out of the way. Alternatively, if you really want to minimize the space it requires when not in use, you would need to disassemble several sections.

This would include lifting the adjustable boom clear of the base frame and detaching the nylon strap that limits the inversion range.

When you consider that the 4000 is the heaviest of the Gravity inversion tables with a product weight of 75 lbs, this is no easy task. Particularly when you consider that you would need to re-assemble these parts the next time you needed an inversion therapy session.

Customer reviews

Despite having the highest price tag in the collection, the Ironman Gravity 4000 is actually their most popular inversion table, and a bestseller on Amazon.

But it’s not just the number of highly rated reviews that makes this such an impressive product, it’s the rating distribution as well.

We really struggled to find a large enough sample size of negative reviews to base our list of ‘cons’ on. Particularly if you exclude very rare occurrences of damage to packaging which aren’t really a reflection on the quality of the product.

However, with well over 1500 reviews on Amazon alone, we would hardly expect you to find time to read them all to find those key pieces of unique information that could influence your decision on whether or not it’s the best option for you.

That’s why we read through a large number of these reviews ourselves, including the few that gave a rating of fewer than four stars, so that we could build the following lists of pros and cons.


  • Heel holders feel comfortable and secure, even at full inversion
  • Safety handles are useful for returning to an upright position
  • Multi-layered memory foam adds an extra level of comfort over the lower priced designs
  • High weight capacity and stable frame design
  • Affordably priced for the features available
  • Additional lower back support provided by the removable lumbar pillow
  • Folding design
  • Sturdy construction
  • Easy to assemble
  • Extra long handle on the heel holders reduces the amount of pressure placed on your lower back caused by reaching down


  • The heaviest of the Gravity inversion trainers, making it more difficult to move around
  • No set positions to lock into. To remain in one position after inverting you really need to make good use of the nylon strap
  • Missing the handles that were fitted to the base for the Gravity 3000, which seem to be unique to that model

What’s covered by the warranty?

  • Frame: 1 year
  • Parts: 90 days
Ironman Inversion Table Buyer's Guide

Review Overview

Overall Review Rating

4.5 / 5

One of the questions we asked at the beginning of this review was does the 4000 model represent the best model in the Gravity collection in terms of value for money.

Although it does slightly depend on the price at the time, we would have to say yes.

Taking a look at the earlier generation 3000 model, this has a list price of around $230, which is a lot lower than the list price of $349 for the Gravity 4000.

However, the best price we found this model for after taking discounts into account was $199 on Amazon. This prices it at almost exactly the same level as the $195 we found the 3000 model for.

At first glance this seems like an excellent saving, but you have to consider they're virtually identical in terms of features.

They have the same warranty, weight capacity, inversion range, memory foam back support, range of height settings, and ratchet release system for the cushioned heel holders. This seems to suggest the price difference is really just for the lumbar pillow.

Overall, this goes to show how similar the Gravity 3000 and 4000 models are, and that each can provide the same health benefits for virtually the same price.

Product dimensions: 49" (L) x 26" (W) x 65" (H) Product weight: 75 lbs Weight capacity: 350 lbs Height range: 4'10" to 6'6"

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