Russia has a larger population than Ukraine, and thus the luxury to not need everyone, and still they have called in reservists in "partial mobilization", exact number unknown. As Russia has conscription, every adult man who has performed their service is in reserve. As of 2023, reservists called into service are not allowed to leave and are subject to restrictions until they report to duty, which seems like high-tech enforcement/"kidnapping" to me. The conscriptions have also hit poorer regions, often with large ethnic minorities, more harshly, but I'm sure that's just coincidence.

There are reports of some military districts closing borders, of mobilized men being ill-equipped and used as cannon fodder, being killed in large numbers, you name it. As with all war reporting, hard to get well-verified factsfacts, especially from a country hostile to neutral reporters. We do know that protests are broken (and male protestors sometimes drafted).

But yeah, probably not needing troop replacements to the same extent as Ukraine. Who, I'm saying again, are fighting for the survival of their country and culture.