Muslim here. Ritual prayer is the core exercise. Before sunrise, after sunset, and 3 other times during the day. But as important or more so is constant remembrance of God. If that's not institutionalized in one's day-to-day psychology, one will lose spiritual momentum, if we can use such terminology. "Worship" in Arabic عبادة actually means something like "conformity to God's order", as far as I understand. So even eating an apple becomes a spiritual exercise when done with knowledge of why and doing so for God's sake, even as its sole beneficiary seems to be oneself.