Heart rate during Cardio VS Weights?


i've been lifting weights for several weeks and usually my heart rate stays within 70-80% of my Max heart rate. Recently i started using stationary bike and even with light exercise my HR goes 80-90% and i sweat hard. is that normal? and is it safe to keep heart rate at 90% for a long time?



https://answers.yahoo.com/question/i...7041624AAelbwQ