It's still ~100 hours a week: 6 days at up to 16 hours = 96 hours/week.

There’s a cumulative “in-hospital” time cap of 80 hours/week (88 for neurosurgical residents). In practice, however, this means that (a) the cap is regularly broken or (b) residents end up doing preparatory study, reading papers, doing research, etc outside of the hospital to remain under the cap. They are still working more or less the same hours.

Also, the 16 hour/day rule is only for interns, IIRC. Resident shifts can go up to 30(?) hours.