Olympic champion Callum Skinner says he is "taking some time away" from cycling but is still targeting Tokyo 2020.
The Briton missed the recent European Championships and has not raced since winning 1km time trial bronze at the Commonwealth Games in April.
Skinner, 26, won team sprint gold and sprint silver on the track at Rio 2016.
"I wasn't able to continue that upward trend, or momentum, that I found at the Olympic Games," the Scot told BBC Radio 5 live's Friday Sports Panel.
"Whether it was that the training wasn't quite right or my head wasn't in the right place or my motivation wasn't quite what it once was, I needed to take some time to step back and re-evaluate and see where to go from there."
Skinner said British Cycling was supportive of his decision and that he is still in training to maintain muscle mass, which is "the most important thing for a sprinter".
"Tokyo is still very much on my mind," he added. "British Cycling are all about the Olympics so I'm very grateful to them for giving me space to re-evaluate things and see how I can push forward all the way to there."
Skinner said he had not picked his return date but cited the example of six-time Olympic champion Jason Kenny, who secretly retired after Rio but reversed his decision to return after a year off.
He said he found it "tough" after winning gold in Rio to find the same motivation, as that goal had been his "sole focus" since turning professional at 17.
"There's a bit of a transition in pressure as well - when I was trying to break into the team I was more or less unheard of, so expectations are kind of neutral," he said.
"Whereas now people, quite rightly, expect a result every time I take to the track."