Content Analysis of Patent Applications for Strength Training Equipment Filed in the United States Before 1980.

Nuzzo, JL. Content analysis of patent applications for strength training equipment filed in the United States before 1980. J Strength Cond Res 35(10): 2952-2962, 2021-Strength training history is an emerging academic area. The aim of the current study was to describe quantitively the history of inventions for strength training equipment. Content analysis was conducted of patent applications for strength training equipment filed with the U.S. Patent and Trademark Office before 1980. Applications were identified using relevant keyword searches in Google Patents. A total of 551 patent applications were analyzed. The earliest application identified was filed in 1860. Applications never exceed 6 per year until 1961 after which applications increased substantially, with a peak of 54 in 1979. Men invented 98.7% of all strength training devices. Lloyd J. Lambert, Jr. was the most prolific inventor, with 10 inventions. Types of inventions included mobile units (34.5%), stationary machines (27.9%), dumbbells (16%), racks or benches (8.0%), barbells (6.7%), and Indian clubs (3.8%). Common features included seats or benches (18.7%), cable-pulley systems (15.1%), weight stacks (8.2%), weight trays (4.5%), and cams (2.2%). Common types of resistance included weights or plates (33.2%), springs (11.6%), friction (9.1%), elastic bands (5.3%), and hydraulic (3.8%). Proposed invention benefits included adjustable resistance (37.4%), inexpensive (36.1%), simple to use (32.8%), compact design or easy storage (27.0%), multiple exercise options (26.1%), safety and comfort (25.4%), effectiveness (23.6%), portability (20.5%), adjustable size (15.8%), sturdiness or durability (15.8%), home use (13.6%), and light weight (13.6%). Certain aspects of strength training equipment have evolved over time. However, overall purposes and benefits of inventions have remained constant (e.g., affordability, convenience, personalization, safety, and effectiveness).