Maximum/Target HR question

WildcatMom82

The high range of my target workout zone is 162 - even when I was in good shape and running 15-20 miles a week my HR was normally steady around 170/175 during my workout. I went out for my first jog in about a year and started slow, but even jogging as slow as I physically could my HR jumped to 187. I finally got it down and held around 180, walking if it got much higher, but is that still too high?

I also realized halfway through I wasn't sweating so I was obviously dehydrated (I usually drip) which may have been part of the problem.