heart rate question from a beginner

Starting weight - 256lbs
Current weight - 193lbs
Height - 5ft 5
Resting HR - 54bpm

I have recently started the gym and i really havent a clue whether i am pushing myself enough. Today i done a circuit training fitness class for 45 mins then i done interval training at the gym for another 45 mins. My heart rate went up to 160bpm but averaged between 130 - 150. Am i pushing myself hard enough.

I think it would help to know your age. I'm not the expert but everything I've seen which recommends heart rate ranges asks for your age.

I go by the "talk" test. At moderate intensity, you should be able to easily talk but not sing. At high intensity, you would have trouble talking more than a few words at a time without pausing for breath.

I find the '220 minus age' estimate of your max heart rate to be wildly off for me. I think you should find your own max heart rate or an approximation by seeing how high it goes using your hr monitor, at your hardest working. Say you find that you can't get your heart rate above around 195. Do your 'zone' percentages from that. So if you want to work out at least partly at 75-85% of your max heart rate, aim for (195 * 75-85%) = 146-166. If you want to spend most of your workout time at 65-75%, calc those. How you want to split it up is up to you. Usually you want to mostly be exerting yourself (can't sing or give a speech) but able to converse in short sentences (not gasping for breath).

I had the same questions when I started out. Like it was mentioned before, there seems to be some variation on how to find your correct zones. The link below maintains several. I ended up doing them all and kind of using a weighted average to set up what I wanted my target heart rate zones to be on my phone app. (Accounting for resting heart rate seemed to make the most logical sense). To tell the truth, there's not that much variation in them either -- so any probably would have worked.

I will say that keeping my heart rate in the "target zone" seems to work pretty well for effective weight loss, etc over just winging it.

http://wserver.flc.losrios.edu/~willson/fitns304/handouts/heartRates.html

I tried a bunch of the calculators I found too, and they all gave similarly consistent numbers. I would feel pretty confident with an average or just about anywhere in the mid range they came up with. They were also consistent with the suggested range of the elliptical I use regularly.