Each athlete is unique, and each reacts to hockey conditioning stimuli in his or her own individual way. (See 3-Week Conditioning Program for Hockey.) However in the conditioning world, a protocol called Tabata is surfacing as king. Created in Japan by Izumi Tabata, Tabata is hailed as the perfect method to lose fat, but I think it's equally effective for hockey conditioning.
To achieve optimum endurance, players need to replicate an actual shift on the ice as closely as possible. Tabata programs use a two- to five-minute warm-up followed by eight straight minutes of 20-second drills at full intensity followed by 10- second rests, finished by two to five minutes of cool down. (See also Improve Conditioning With Tabata Interval Training.) This training method can be implemented in various ways, but I think the stationary bike is the best option. You can adjust the resistance, so select a level that makes it difficult to complete a 20-second sprint, while focusing on maintaining an rpm of 120-130.
Research has shown that hockey players that perform the Tabata protocol were able to achieve elevated cardiovascular output levels and increase their strength and size due to the resistance during the sprint phase. Ideally, each athlete can fit this method in with his or her other on- and-off-ice conditioning programs. The research suggests that best results come from performing the protocol at least twice a week. My suggestion is to complete the protocol on your leg off-days or on plyometric workout days. If you are unable to complete a full 20-second sprint at an all-out pace, drop the sprint intervals to 10 seconds and keep the rest interval at 10 seconds.
Considering its high intensity and short durations, the Tabata protocol is one of the best methods for conditioning. On a twice-a-week schedule, you will be dedicating just 30 minutes per week to a workout that will produce significant increases in cardiovascular endurance, as well as increased leg strength. Start out small and see where it takes you.