Squat challenges are a waste of time. You need to be doing weighted squats to actually notice a difference. Doing squats without any weights won't make any difference. You shouldn't be doing squats every day either - if you're doing them properly you physically won't be able to as you'll be too sore. 2 or 3 times a week is recommended.
Look up what qualified trainers have to say about squat challenges, they all say what I've said here.
I have weights so could add those but yes, it'd be too much to do daily- the challenge starts on 50 and builds up to 250 a day. I really was looking for a fast track to get back the half-decent leg/bum muscles that I had pre DC. I would do high intensity but I don't have the room downstairs and would wake the DC up if I did it upstairs. Work full time so can only really do when kids asleep.
Its better to do squats with weights as part of a varied strength training programme. I as the DC to get on my back and you can really feel it! Ten squats with a ten Yr old on your back feels a lot more productive than loads without resistance!
There is no fast track to getting decent leg/bum muscles - they're one of the hardest body parts to sculpt and take months. Doing hundreds of squats a day with little or no weight won't do anything apart from knackering you out. Heavy weights with lower reps and good form 2/3 times a week is the best way.
I'm not qualified but I've been weight training for 4 years and this is what I was told by PTs.
I was hoping that "muscle memory" was going to help me at least partly. Perhaps not. Thaks I'll check out those suggestions @chardonnays. I'm happy to do heavy weights 2/3 times a week but I (weirdly) find daily exercise is easier for me to stick to so that's why I thought of the challenge. I suppose I could do arms on the other days.