Aspiring Olympic and Paralympic swimmers in Wales will be able to train in a pool for the first time in three months on Wednesday.
Ten athletes will begin a "four-to-six-week closed-door training camp" in Newport.
The pool at the Newport International Sports Village will open exclusively for the group after the Welsh Government allowed a select number of Welsh elite athletes to resume training under certain conditions.
In a statement, Swim Wales said it was "delighted" to oversee a resumption of elite training after "several weeks of negotiations and planning".
The statement continued: "The Swim Wales performance team, supported by medical staff, have completed all athlete one-to-ones and group safety orientation sessions and are delighted with the condition and general health of all of our athletes.
"Swim Wales are grateful to Sport Wales, Welsh Government and the operational team at Newport Live for facilitating this essential next step on the road to the Tokyo qualifiers next year."
Elite athletes in England - including many top swimmers - have been allowed to train again since May.
That led to a warning from Swim Wales chief executive Fergus Feeney that the performances of Welsh Olympic and Paralympic hopefuls could be "compromised" if they were not allowed to follow suit.
As part of the relaxation of coronavirus lockdown restrictions, the Welsh Government had given permission for a small group of elite athletes from swimming, athletics, gymnastics, boxing and squash to train again from 22 June, subject to training protocols being signed off by Sport Wales.
Olympic and Paralympic hopefuls from athletics were the first to resume training in a controlled outdoor session on Tuesday, with the swimmers set to follow suit on Wednesday.
Gymnastics and squash hope to resume at the Sport Wales National Centre within the next week. Wales' top amateur boxers are due to train again there later in July.
Sports such as track cycling, rhythmic gymnastics and judo are due to resume elite training in the next phase, with team sports such as hockey and netball following later in the summer.