Which training method focuses on continuous exercises at variable intensities?

Fartlek training is a method that emphasizes varied intensities during continuous exercise, combining steady-state running with bursts of speed or changes in intensity. The term "Fartlek" comes from Swedish and means "speed play," reflecting its nature of integrating different pace variations throughout the duration of the activity. This approach effectively mixes aerobic and anaerobic work, which can lead to improvements in both endurance and speed. It is particularly beneficial for runners and athletes looking to enhance their performance by adapting to different paces, making their training sessions more engaging and practical for competitive scenarios.

The other options represent different training methods: circuit training involves a series of exercises performed in sequence, generally targeting strength and endurance; continuous training focuses on maintaining a steady pace for an extended period without rest, typically at a consistent intensity; and interval training alternates between periods of high-intensity effort and lower-intensity recovery. Each has its specific focus and benefits, but they do not incorporate the same flexibility in intensity found in Fartlek training.