i did the 2 minute squats challenge .
the first day i could do 107 and the second day i tried 160 half squats .
and started feeling muscle cramps.

and had to stop doing workout completely for 2 days.

so what i suggest while doing such heavy exercise:

1. do warm up before and after ( basically stretching ), at least 2 mins
this will reduce chances of cramps but still if it comes which is pretty common then.
2.take rest for at least 2 days which means 8 hours of sleep .
3.massage twice gently preferably before sleep with oil .
4.take warm or hot water shower twice .
5.have plenty of water.
6.maintain high nutrition (vitamin D, proteins)
and have patience because the time taken is utilised buy your muscles to build.