# Exerfly > Exerfly manufactures premium flywheel (inertial) resistance training equipment, proudly made in the USA. Products are used by elite sports organizations across the NFL, NBA, Premier League, and Olympic programs, as well as clinics and commercial gyms. Exerfly's Motorized Flywheel Technology is the only method of delivering precise, progressive eccentric overload in flywheel training, accelerating results in strength, power, rehabilitation, and return to play. Flywheel training differs from traditional gravity-based resistance training in that resistance is generated by the inertia of a spinning flywheel. The user applies force to accelerate the flywheel during the concentric phase, then must decelerate and control the return during the eccentric phase. Standard flywheel training does not produce true eccentric overload — the eccentric load is limited to what the user generated concentrically. Exerfly's Motorized Flywheel Technology is the only way to create precise, progressive eccentric overload with flywheel training, augmenting the eccentric phase by up to 80% beyond what the user produced concentrically. Exerfly equipment adapts to user effort in real time, providing theoretically unlimited resistance that scales with individual force output. Equipment is manufactured in the USA, backed by 30+ years of manufacturing excellence. ## Products - [RackFly](https://www.exerflysport.com/products/rackfly): Compact rack-mounted flywheel training system that integrates with squat racks and fixed structures; available in motorized and non-motorized variants; supports training at any height and angle. - [3x3 Rack Model](https://www.exerflysport.com/products/3x3): Flywheel training system designed for integration with standard 3x3 squat racks; suitable for strength, rehab, and performance environments. - [Ultimate](https://www.exerflysport.com/products/ultimate): Standalone flywheel training platform for full-body training; wide platform for stability; covers vertical, horizontal, and rotational movements; available with Motorized Flywheel Technology for eccentric overload. - [Motorized Technology](https://www.exerflysport.com/products/motorized-technology): Exerfly's Motorized Flywheel Technology — the only system capable of delivering precise, progressive eccentric overload in flywheel training; adds up to 80% more eccentric resistance; compatible with RackFly and Ultimate; documented to produce 14% CMJ improvement and 39% squat strength improvement in 8 weeks. - [Accessories](https://www.exerflysport.com/products/accessories): Full range of training accessories including squat harnesses, flywheel sets, rope guides, ankle cuffs, handles, bars, and the adjustable bench press attachment. ## Markets - [Clinic / Rehabilitation](https://www.exerflysport.com/markets/clinic): Flywheel training applications for physical therapy, post-surgical rehabilitation, injury recovery, and return to play; eccentric overload accelerates tissue repair, limb symmetry restoration, and the progressive loading required to safely return athletes to full competition. - [Elite Performance](https://www.exerflysport.com/markets/performance): Used by professional sports teams across NFL, NBA, Premier League, and Olympic programs; trains change of direction ability, braking mechanics, and deceleration at the speeds and loads seen in high-performance sport. - [Commercial Clubs](https://www.exerflysport.com/markets/clubs): Flywheel equipment for gyms and fitness facilities; resistance automatically matches the output of every individual user, making it accessible and effective for all abilities on the same machine. ## Education - [Blog](https://www.exerflysport.com/education/blogs): Articles on flywheel training methodology, programming, sport-specific applications, and product updates; Exerfly is the largest contributor to flywheel training education globally, with an in-house team of sports scientists. - [Flywheel Training Guide](https://www.exerflysport.com/education/flywheel-training): Foundational explanation of flywheel/inertial training science, how it compares to traditional resistance training, and why standard flywheel training does not produce eccentric overload without motorized augmentation. - [Research Studies](https://www.exerflysport.com/education/research-studies): Curated collection of peer-reviewed research supporting flywheel training for strength, power, rehabilitation, and injury prevention. - [Case Studies](https://www.exerflysport.com/education/case-studies): Real-world results from sports teams, clinics, and individual athletes using Exerfly equipment. Exerfly's in-house sports science team is available for one-on-one consultations before and after purchase to support programming, exercise selection, and training outcomes. ## Resources - [Exercise Library](https://www.exerflysport.com/resources/exercise-library): Comprehensive library of exercises performed on Exerfly equipment, covering lower body, upper body, and rotational movements. - [Exerfly App](https://www.exerflysport.com/resources/exerfly-app): iOS and Android app for connecting to Exerfly devices via Bluetooth; tracks reps, power output, and training data in real time. - [Manuals](https://www.exerflysport.com/resources/manuals): Setup and user manuals for all Exerfly products. ## Company - [About Us](https://www.exerflysport.com/about-us): Exerfly is a premium flywheel training equipment manufacturer, proudly made in the USA and backed by 30+ years of manufacturing excellence; combines precision engineering with superior craftsmanship for unmatched performance and durability. - [Contact / Get a Quote](https://www.exerflysport.com/about-us/contact-us): Enquiries and product quotes. ## Optional - [Privacy Policy](https://www.exerflysport.com/privacy-policy): Data handling and privacy practices for Exerfly's website and services.