How fast do I need to go

[Deleted User]

I've just bought a Precor EFX544 crosstrainer but after using it for a few sessions I am perplexed as i don't seem to be working hard enough. Even though I'm ending my 30 minute sessions with pretty tired legs I'm struggling to get my heart rate much above 130 even when I'm cracking along at 170 strides a minute. Anyone any experience of these machines able to offer any advice I'm 47 withh a resting HR of 50 and a max of 178.