yeah, warmups are highly encouraged...and these are just plain rough...it's really using your body in a way that very very few people today do...so ease in, don't push too hard...a little bit here and there is the way to get stronger. it builds up fast...but those 60 jumpsquats I did was 'too many'...I think if you're sore for 1-2 days, great...if you are sore for 3-5 days that was too much.