I've been trying to transition to <10% body fat, having started at around 16% BF, and the cut has lasted for 3/5 months now (~15 weeks).
I'm concerned though about what the consequences might be of continuing to cut, in terms of a long-term reduction in metabolic rate/thyroid function. I'm not sure that this kind of thing happens if you're cutting slowly and sensibly, or whether it's a risk when you're extreme dieting?
You see a lot of advice from people regarding cut duration, and they tend to fall into either (a) cut for x weeks or (b) cut until you're happy. I'd estimate that I'm around 12-13% BF currently, so if possible/healthy I'd like to continue cutting until I'm <10% as planned. However as mentioned I'm concerned about the impact this might have long-term.
So my options as I see them are as follows:
(a) Continue cutting until I'm happy, however long that may be.
(b) After 4 months, have a maintenance phase of a few weeks to 'normalise' my metabolism, then start again.
(c) After the 4 months go back to a slow bulk and then just cut 'better' next time.
I think it's relevant to note that I've been cutting on ~2,500 calories a day, using mainly sprints for cardio and a fairly basic upper/lower split. My strength has not decreased during the cut but has maintained steadily (perhaps even adding a rep or two here and there).
Any help is appreciated.