Long slow distance (LSD) is a form of aerobic endurance training in running and cycling. Physiological adaptations to LSD training include improved cardiovascular function, improved thermoregulatory function, improved mitochondrial energy production, increased oxidative capacity of skeletal muscle, and increased utilization of fat for fuel.Ernst van Aaken, a German physician and coach, is generally recognized as the founder of the long slow distance method of endurance training.

Long slow distance training is a form of continuous training performed at a constant pace of low to moderate intensity over an extended distance or duration. The moderate training intensity of LSD is effective in improving endurance and maximum oxygen uptake in individuals who are undertrained or moderately trained. Long slow distance training is thought not to be effective when used in isolation by well-trained athletes, who in order to achieve further improvements in metabolic conditioning require higher training intensities that are not sustainable at the work durations associated with LSD.

Sivert Høyem (born 22 January 1976) is a Norwegian singer, best known as the vocalist of the rock band Madrugada. After the band broke up due to the death of Robert Burås in 2007, he has enjoyed success as a solo artist and is also a member of The Volunteers with whom he released the album Exiles in 2006.

Høyem rose to fame in the late 1990s when Madrugada made their Norwegian breakthrough with debut album Industrial Silence. The band members included Sivert Høyem (vocals), Frode Jacobsen (bass), and Robert Burås (guitar). After the death of Burås on 12 July 2007 Høyem and Jacobsen decided to finish recording their latest album. The album, entitled Madrugada, was released on 21 January 2008. After the release of the album the band announced they would split after one last tour. They performed their last ever concert on 15 November 2008 at Oslo Spektrum in Oslo-Norway.

He has the last few years had success as a solo artist, releasing the albums Ladies and Gentlemen of the Opposition (2004), Moon Landing (2009) and Long Slow Distance (2011).