Hello Justduckie...

Warning: I ain't no doctor or nutritionist or in any kind of health profession, just a sociologist and caring person.

You don't say how much you weight right now, but by rule of thumb, you certainly shouldn't be under 145-150 lbs, and it would be very normal for you to weight much more if you're, as you say, mostly muscle. This is not a big scientific rule, just a general ball park: 100 lbs + 5 lbs per inch above 5', 6 lbs for a man. I trust it more as giving us a threshold we shouldn't be under than as an upper limit.

I am totally floored by what I head among the cycling/fitness community on the topic of weight. It's similar to the kind of things I'd hear earlier in my life in gymnastics and ballet. Both men and women are quite concerned, and sometimes obsessed, with weighting less. I can understand that, up to a point: carrying those pounds up hill on a bicycle or having your feet support them when running can be seen as impairing our performance. We also see all quite a few athletes that weight seemingly nothing and climb up hills so quickly... Sports magazine do not help much. This gives a totally new meaning to the title of this old book, "Being at 10 kg of happiness", which so many women (but more and more: men) always are.

But the truth is, it's not necessarily healthy for us to be like that (nor is it for these professional cyclists, mind you, but that's a different story), and if your body is resisting weight loss, it's maybe better for you, health-wise. Yes, maybe you'd climb faster, but you'd loose precious muscular power in other life circumstances, potentially increasing risk of injuries in other situations, etc. I imagine creating a deficit in your calorie intake also has consequences.

So my message is: try seeing a doctor or nutritionist before going further with your plan to loose 20 pounds. Maybe find someone who's sports oriented if you cann. If it is okay for you to loose them, a professional will give you cues that are certainly safer than home experimenting...

Good luck!