I woke up today with a really sore neck and upper back - dunno what I’ve done, I probably slept on it funny. Anyway today is legs day - should I still lift weights, or should I just do cardio?

I’m going home for the mid year break in about a week and will lose my access to the uni gym :( Which is fine for strength workouts, because I have some handweights at home. But for cardio, any ideas what I can do?

I already run three times a week and don’t want to do more than that (I have a bad knee…) but want to do cardio at least 5 times a week. 

Suggestions?