The Australia captain has been ruled out of the series opener against England due to a back stress injury discovered after the 3-0 whitewash of the West Indies in July.
But Cummins bowled for almost an hour on Monday as he trained with his Australia teammates in hot conditions at Perth Stadium.
Australia's squad only arrived in the Western Australian capital on Sunday to begin preparing for the start of the first Test.
After completing the session, Cummins gave a little fist pump to his teammates.
He then spent time speaking to South Australia quick Brendan Doggett, who is expected to make his Test debut.
Australia's fast-bowling attack for the first Test will be Mitchell Starc, Scott Boland, and Doggett.
There were fears Cummins could miss most, if not all, of the Ashes due to the most serious injury he has suffered since 2016.
But any appearance this summer is sure to worry England, with Cummins having never lost against them since his Ashes debut in 2017-18.
Having a week off before the second Test at the Gabba should help Cummins' bid to be ready.
Also working in his favour is that Brisbane's will be a day-night Test, which have been historically less strenuous on bowlers.
But Cummins has previously conceded he would be unlikely to play out the rest of the summer unchanged once he is fit.
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