Soldato
Fit for military service in Russia is in the 20-30 millions for both genders, obviously can't send all of those as some will be needed for services, manufacturing, etc. though on a full war footing they'd start mobilising women into those roles to free up men for the frontlines.
There is a substantial number of the most fit age range who have left the country but Putin has been emptying out many of the poorer regions first - you'll be seeing older people more because he'd rather sent a 70 year old from the Russian far east than a 20 year old from richer western regions - ironically some of the border regions with Ukraine have been almost untouched by conscription/mobilisation - in the footage of Wagner's uprising the towns are full of young adults while on the other hand some of the poor villages are bemoaning there are hardly any men left.
Russia is slowly ramping up equipment production for example a redesigned, with quality issues, AK-12 is increasingly appearing with Russian troops with production expected to ramp to mass production levels in the second half of this year.
They'll need to ramp up production as stockpiles won't last forever.
As the production and recruitment drives up they'll go onto more of a war footing, but that has a cost to the economy itself as well.