Some flexibility in terms of which hours of the day you are working, could do a quick gym session some days of the week. However, most of the time you make up the time you spent not working. On occasion you may not need to make up the time. Just depends on deadlines. Some weeks you may not be able to go to the gym at all. Generally on projects, people come into office 4-5 days a week. While not on project, not as much of an expectation to be in office. Remote work is possible but you need to flag this in advance.
Granted consulting expected hours. WFH, admin days post project, flexible start times (i.e 10am starts) and chance to take flexable OOO.
I think flexibility is moderate. Workload is high and timelines are crunchy, but PLs generally understanding of personal commitments and can cater for flexibility. Remote work unsure.