Of the four major team sports in the United States, training for hockey in the offseason is the least convenient.
Not everyone has access to an ice rink where they can skate and work on drills during the offseason. But improvements to synthetic ice in recent years have made it a feasible offseason training product.
Synthetic ice came onto the market in the 1950s as a way to skate outdoors because it does not require electricity to operate and can withstand warm temperatures. But the plastic used six decades ago (polyoxymethylene) caused great resistance, made it difficult to skate on, and even with lubricant added, the surface was uneven.