Pilates reformer springs vs. cords: Which should you buy?

Shop for a home Pilates reformer and you'll hit the springs vs. cords question fast. Budget machines, mostly from AeroPilates, use elastic bungee cords. Studio-style machines from Balanced Body and Merrithew use steel springs.

Does the difference matter? Less than you might think for how resistance builds, and more for adjustment, upkeep and matching what you do in a studio.

The short answer

• Choose cords if you're a beginner on a tight budget and mostly follow app or video workouts. The AeroPilates 287 and 4420 are the usual picks, and the 4420 folds away (see our best foldable reformers guide for others). (Budget cord and spring machines weigh about the same: 56–63 lb for the AeroPilates 287/4420 per Stamina, 65 lb for VEVOR's S1002 per VEVOR.)
• Choose springs if you take studio classes and want the same setup at home, want finer color-coded resistance steps, or plan to keep the machine for years. Look at the Balanced Body Allegro 2 or Metro IQ, or the Merrithew At Home SPX. Spring machines Under $500 exist too, such as VEVOR's S1002. AeroPilates also sells several spring models, per Stamina's store, from the Precision Series 535 (Under $500) to the Pro XP 557, Precision Series 610 and Pro Series 565 ($1,000+).

Springs vs. cords at a glance

Counts come from the Balanced Body, Merrithew and Stamina product pages listed below. Lower-cost spring machines exist too (see machines in each camp).

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How reformer springs and cords differ

Resistance feel

Both springs and elastic get harder to stretch the further you pull them. For a steel spring, that's Hooke's law: the force is directly proportional to the stretch, as OpenStax's college physics text explains.

Elastic behaves in a similar way. A study of Thera-Band elastic bands by Uchida and colleagues (Journal of Physical Therapy Science, 2016) found that "the more the band is stretched, the greater the resistance to further elongation." Tension rose linearly as the bands stretched from 25% to 250% of their length. A 2005 study of elastic tubing by Thomas and colleagues found the relationship "is linear beyond a threshold in the early part of elongation."

Balanced Body, which sells spring reformers, argues the feel still differs. It says steel springs "provide variable resistance and continuous neuromuscular feedback throughout a movement," while "elastic cords lack the nuanced variable feedback of steel, changing tension drastically throughout the stroke." That's a manufacturer's claim, not a measured result. We found no peer-reviewed study comparing reformer springs and reformer cords head to head, for feel, strength results or durability.

Instructors do care about springs. Mo Wolfe, owner and instructor at Evolution Pilates in Rochester, NY, told Women's Health: "Springs provide resistance and feedback, so the type and responsiveness of springs deeply influence your experience."

Tap the diagram to enlarge

Resistance options and adjustment

Spring reformers change resistance by hooking different springs on or off. Balanced Body says the Metro IQ's five springs (three red, one blue, one yellow) "offer up to 46 resistance options." Merrithew's At Home SPX package has five springs: four at 100% and one at 50% resistance.

Cord machines change resistance with fewer, bigger steps. Stamina says the AeroPilates 4420 has "two black cords, one red extra resistance cord and one yellow light resistance cord." Stamina doesn't publish pound ratings for the cords.

Spring colors aren't standard across brands. Women's Health describes a common modern scheme: green (heavy), red (medium), blue (light) and yellow (extra light). But Balanced Body calls red medium, Merrithew labels springs by percentage, and VEVOR calls its red spring strong and green medium. Check your own machine's chart. Color labels on elastic aren't exact either: the Uchida study found measured band tension ran about 13–44% below the manufacturer's stated values, depending on the color.

Durability and maintenance

NBC Select says both types are adjustable and create resistance, but "metal is a more durable material that may last longer."

The manufacturers' own replacement schedules are close, though:

• Merrithew springs: "Maintain your warranty, replace your springs every 2 years." Merrithew says this applies to "any spring equipment." Some older Merrithew reformers (V2 Max, Pro and SPX series made before December 2011) also need a Metal Spring Holder Upgrade Kit to safely hold new springs.
• AeroPilates cords: Stamina says new cords "will be very stiff. They will relax a little with use and may even need to be retied and replaced after 24 months of very regular use." If a cord has stretched, you can retie the knot under the machine.

Balanced Body sells replacement springs, but we didn't find a recommended replacement interval on its product pages.

Replacement is partly a safety issue. Merrithew says replacing springs every two years helps "keep your equipment operating safely." Whichever type you buy, replace worn springs or cords on your manufacturer's schedule.

Ropes are treated as wear parts: Merrithew covers the SPX's "ropes, straps, spring clips" for one year (versus a limited lifetime on the frame and rails), and Stamina covers AeroPilates parts for 90 days. For general care, Merrithew says to wipe the channels, rails and rollers daily with a damp cloth and to "never use oil lubricants as they may damage rollers."

Studio carry-over

If you also take reformer classes, studio machines use springs. Women's Health quotes Wolfe recommending "four high-quality springs, ideally with equal tensions." Today.com quotes Elaine Hayes, owner of MNT Studios, who suggests looking for "at least five springs with varying tensions," plus ropes with loops, an adjustable footbar and a comfortable carriage.

Balanced Body says studio-grade reformers have "a minimum of 5 high-quality, custom-tuned steel springs" (again, a brand claim).

Cost

Price is the main reason cord machines exist. Women's Health says cords "offer the same effectiveness, and they are more affordable," though it also concludes that "ultimately, a reformer with springs is of higher quality." It lists "uses cords instead of springs" as a con of the AeroPilates 4420.

In our catalog, the AeroPilates 287 and 4420 are in the Under $500 tier. Balanced Body and Merrithew spring reformers are $1,000+. VEVOR's spring machines, such as the S1002, start Under $500 (the wooden Z88 is $500–1,000).

Machines in each camp

Specs are from each manufacturer's product page, except VEVOR's warranty. "Not listed" means it wasn't on the page we read. VEVOR's 12 months is its general product warranty, per VEVOR's return policy (the Z88 page also lists a 12-month warranty); it doesn't say whether that covers the frame specifically.

Cord reformers

• AeroPilates Reformer 287: Stamina lists "3 heavy-duty, elastic bungee cords," clips for quick rope-length changes, a 300 lb max user weight and a 56 lb machine. Warranty is 3 years on the frame and 90 days on parts.
• AeroPilates Reformer 4420: Four elastic cords (two black, one red, one yellow), 300 lb max user weight, 63 lb machine, same 3-year/90-day warranty. Today.com describes the 4420 as having "four tension springs," but Stamina's own page says cords, so we go with Stamina.
• AeroPilates Premier: NBC Select describes it as having "four resistance cords."

Compare all of them in our AeroPilates models guide.

Check price on Amazon

Spring reformers

• Balanced Body Allegro 2: Five springs (three red, one blue, one yellow), which Balanced Body says are "nickel-plated for durability," with Spring Collars for easier changes. Heavier DURO Springs are an option for busy studios. 10-year frame warranty.
• Balanced Body Metro IQ: Five springs with "up to 46 resistance options," per Balanced Body, and a 2-year non-commercial warranty.
• Merrithew At Home SPX: Five springs (four 100%, one 50%), 250 lb capacity, limited lifetime warranty on the frame and rails. Merrithew says it isn't warrantied for commercial use.

Check the Allegro 2

Other spring and hybrid options

• VEVOR foldable (S1002): VEVOR calls it its "Foldable-Entry-level Model," with five steel springs (three red, two gray), a 400 lb max user weight and a 65 lb machine. It's a spring machine in the Under $500 tier, though VEVOR has less of a track record than the studio brands.
• AeroPilates spring models: The Pro XP 557 is one of several AeroPilates models with springs. Stamina says it has "four steel springs," a 300 lb rating, a 158 lb machine weight and a 5-year frame warranty, longer than the cord models. Stamina also lists the Precision Series 610 (four steel springs, two light and two heavy) and the Pro Series 565 ("Four Heavy-Duty Springs"), both $1,000+, and the Precision Series 535 ("four levels of spring resistance"), Under $500 on Stamina's store. We didn't compare these models beyond Stamina's descriptions.
• VEVOR wooden foldable (Z88): VEVOR lists five springs ("1 strong spring (red), 3 medium springs (green), and 1 light spring (yellow)") plus elastic cords in a dual system, rated up to 400 lb. Our VEVOR reformer review covers its other models, including the springs-only ones Under $500.

Check the Pro XP 557

Can you switch a cord reformer to springs?

We found no manufacturer kit that converts an AeroPilates cord model to springs. If you start on cords and want springs later, the practical upgrade is a spring machine, such as one of AeroPilates' own spring models or one of the other spring machines above.

Frequently Asked Questions

Are springs or cords better on a Pilates reformer?

Editors lean toward springs. Women's Health calls spring reformers "of higher quality" but says cords "offer the same effectiveness" for less money. NBC Select says both work, but metal "may last longer." Cords are a reasonable way to start; springs are closer to studio machines.

Do AeroPilates reformers use springs or cords?

Most use elastic bungee cords: three on the 287 and four on the 4420, according to Stamina. Some AeroPilates models use springs instead, including the Pro XP 557, Precision Series 610 and Pro Series 565, per Stamina.

How often should you replace reformer springs?

Merrithew says to replace springs every two years to keep the warranty and keep the machine safe. Stamina says AeroPilates cords may need retying and replacing after about 24 months of very regular use. Follow your own manufacturer's schedule.

What do the spring colors mean on a reformer?

It depends on the brand. Women's Health gives a common scheme: green heavy, red medium, blue light, yellow extra light. Balanced Body uses red (medium), blue (light) and yellow (very light). Merrithew labels springs by percentage (100% and 50%). Check your machine's chart.

Do resistance cords lose tension over time?

Stamina says new cords are stiff, "will relax a little with use," and can be re-knotted when they stretch. Separately, a 2016 technical note found Thera-Band bands measured about 13–44% below their labeled tension (it didn't study wear or reformer cords). We found no study comparing how reformer cords and springs wear.

How many springs should a home reformer have?

Women's Health quotes instructor Mo Wolfe recommending four high-quality springs; Today.com quotes Elaine Hayes suggesting at least five with varying tensions. Balanced Body says studio-grade reformers have a minimum of five (a brand claim).

The verdict

Cords cost less, and Women's Health says they "offer the same effectiveness." Springs are what studios use, and they give finer resistance steps. NBC Select says metal may last longer, but the makers' own schedules are similar: Merrithew says to replace springs every 2 years, and Stamina says cords may need replacing after about 24 months of heavy use. Don't let durability alone decide it.

If you're testing the waters on a budget, a cord machine like the AeroPilates 4420 is fine. If you take classes or plan to keep the machine for years, buy springs. If you take classes and can spend $1,000+, the Allegro 2 or Metro IQ match studio machines most closely. If you can't, a lower-cost spring machine such as VEVOR's S1002 gets you springs Under $500, but VEVOR has less brand track record. Either way, budget for replacement cords or springs on the manufacturer's schedule.

Check the 4420 (cords) Check the VEVOR S1002 (springs, Under $500) Check the Allegro 2 (studio springs)

Browse all home reformer guides for more options.

Sources

• Balanced Body: The ultimate guide to the Pilates reformer (brand claims)
• Balanced Body: Allegro 2 Reformer
• Balanced Body: Metro IQ Reformer
• Merrithew: At Home SPX Reformer Package
• Merrithew: Spring center
• Merrithew: Spring center FAQs
• Merrithew: Product care
• Stamina Products: AeroPilates beginner's guide
• Stamina Products: AeroPilates Reformer 287
• Stamina Products: AeroPilates Reformer 4420
• Stamina Products: AeroPilates Pro XP 557
• Stamina Products: Precision Series Reformer 610
• Stamina Products: Pro Series Reformer 565
• Stamina Products: Precision Series Reformer 535
• Stamina Products: AeroPilates collection (list prices used for price tiers, checked Oct 6, 2026)
• VEVOR: Foldable wooden Pilates reformer
• VEVOR: Foldable Pilates reformer (S1002)
• VEVOR: Return policy and warranty
• NBC Select: Best Pilates reformers (Jan 10, 2024)
• Women's Health (via Yahoo): Best at-home Pilates reformers (Nicolette Accardi, NASM-CPT, May 18, 2026)
• Today.com: Best Pilates reformers (Rebecca Brown, updated July 24, 2025)
• OpenStax: College Physics 2e, Hooke's law
• Uchida et al., J Phys Ther Sci (2016): Thera-band elastic band tension: reference values for physical activity
• Thomas, Müller and Busse, J Sports Med Phys Fitness (2005): Elastic tubing tension study (abstract only)