Confused by Reformer Springs? Here is Your Ultimate Brand Conversion Guide

The Pilates world is filled with amazing Reformer machines, but each one has its own unique language. This is especially true when it comes to knowing the spring weight or color to select throughout your workout. If you're super confused, try this one spring workout with Tracey Mallett to simplify things.

In a Pilates Anytime class, you may hear our teachers state a range of Reformer spring tension or refer to a specific color. One of the questions we get asked is how to know which spring to use. If you've ever switched studios, bought your own machine, or tried an online class only to find yourself guessing the resistance, you've experienced this confusion.

Spring tensions vary from machine to machine and are not always comparable. This makes terms like "light," "heavy", "full spring", or "quarter spring" confusing when used instead of a brand's specific color system. In other words, not all "medium" or "full springs" are the same weight across brands. So basically it's like choosing the right lightbulb; it seems like it should be easy, but you always end up with the wrong shape, color, or size! Let's make sure you end up with the right springs for your workout.

This is your ultimate guide to spring resistance questions. We will break down how Pilates springs work, explain why lighter isn't always easier, and provide definitive, saveable cheat sheets to help you convert resistance levels across the industry's biggest brands. If we're missing any brands, let us know and we will be happy to help!

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How Pilates Springs Work and Why Spring Resistance Matters (and Why Lighter is Often Harder!)

Springs are the heart of the Pilates Reformer. They provide both resistance (to build strength) and support (to provide stability).

Here is the paradox of Pilates resistance: heavier isn't always harder. In most traditional weightlifting, more weight equals more work. In Pilates, it's often the opposite:

• Heavier Springs = External Support. A heavier spring provides more resistance to movement. This requires a strong push/pull away from the starting position. A heavier spring also provides more support and stability. In exercises like Leg Circles, a heavy spring supports the weight of your legs, helping you maintain a stable pelvis, and provides a "closed chain" that gives you something to push against.
• Lighter Springs = Internal Work. A lighter spring provides less resistance. They are easier to move, but they are harder to control. When you take the springs away in a Plank or Elephant, you lose the "brakes." Your core has to become the brake system. It turns the exercise from a strength exercise into a stability and control exercise. This is often when you get the shakes!

Sometimes the most difficult exercise is the one you approach with too light of a spring. When you enter exercises, especially as a beginner, make sure you understand the setup and spring selection so you know what will happen when you start to move. If it's a light spring, pay close attention to what's happening next. Watch the instructor teach the exercise first if you have any doubt.

Understanding how the springs work changes how you approach every exercise. You might notice teachers playing with different spring settings to challenge you in different ways. For example, Footwork is typically done on heavier springs to strengthen your legs and warm up your body. However, if you are quad dominant, you might try Footwork on lighter springs, which might help you find the work in the back of your legs. The work then shifts from pushing out to pulling in. Always adjust springs with the right instruction so you do not find yourself in a difficult situation where you have: a) lightened springs too much to support your body and you feel out of control; or b) made springs too heavy where you feel compressed, overloaded, and strained.

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The Pilates Spring Cheat Sheet : Universal Brand Conversion

This chart uses a universal resistance scale to align the weight of springs in the most popular Reformer brands. Use this to quickly find your ideal tension, no matter what machine you are on. Note that not all of the brands have the exact same weight in each category. That depends on how the springs are made and operate. For some brands, "heavy" may mean a little bit heavier or lighter than other brands. Most classes will spend more time on the Medium/Standard or sometimes called "Full" Spring. The second most used spring is the light spring. Heavy springs are used more sporadically.

Tip: Take a screenshot of this chart! Having this open during your next online workout will change the game.

Here are the spring conversions between Balanced Body springs and commonly used Reformer brands.

Balanced Body springs are shown on the left. Merrithew springs are shown on the right.

Balanced Body springs are shown on the left. Peak Pilates springs are shown on the right.

Balanced Body springs are shown on the left. Your Reformer springs are shown on the right.

Use this sheet below to record your own brand, model and preferred spring equivalents. Approximate only. Spring feel varies by body, carriage position, preload, gear setting, and exercise.

Note: Springs stretch out and lose tension over time. For this reason, a 5-year-old "Heavy" spring on a Balanced Body may feel lighter than a brand-new "Medium" spring on a Flexia. In the industry, we call this "spring fatigue," and it's the one variable a cheat sheet can't perfectly capture. So keep in mind the age of your springs.

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Unique Systems Explained: Other Brands

While the chart above covers the most common color-coding systems, some brands have very different resistance settings.

Gratz: Uniform, Heavy Springs

Gratz is a classical brand that uses uniform heavy springs. There is no "Blue" or "Yellow." You adjust the difficulty not with spring color, but by varying the speed, control, and repetition of the exercise. A Gratz workout is famously demanding for this reason. Many of our classical instructors at Pilates Anytime choose to work on a Gratz. The Gratz Reformer also does not automatically bring your carriage all the way home, even on the heaviest settings. You are required to do that last bit of work to click your Reformer closed.

Balanced Body springs are shown on the left. Gratz springs are shown on the right.

AeroPilates: Bungee Cords

AeroPilates machines use bungee cords instead of metal springs. This creates a slightly "bouncier," non-linear tension that is very smooth, but more difficult to convert to traditional spring counts. If your AeroPilates Reformer has colored cords, Yellow is Light, Black is Standard, and Red is Heavy.

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Conclusion: Take Control of Your Practice

Understanding spring conversions can empower your practice.

• As a Student: You can confidently adjust your home machine to match the instructor's cues and make nuanced adjustments for your machine and your body.
• As a Teacher: You can clearly explain to your clients why you are changing their resistance and what they should be feeling.

Want more information on springs? Watch Ken Endleman of Balanced Body for a complete guide to Pilates Springs selection, maintenance, and applications here .