... Not for reasonably trained athletes

I bought the Cambridge II to an all-weather alternative for my running training to have - as I previously had little experience with rowing machines I found the Christopeit as good offer to the thing a try.
The device provides for 129, - generally good quality; the parts act with value and the assembly instructions are detailed and easy to understand. Rudimentary tool to the rowing machine within about 45 minutes to build up is also included. The train system used with latex rope is in principle secure a cost-effective and good alternative to more expensive machines, unfortunately, is here but for me the biggest problem:
Somewhat trained athletes, which are for example used 2-3 times a week to run and / or participate regularly strength training under calls the device itself in the most difficult settings across the board. After 45min intensive rowing on severe stage I got my pulse scarcely more than 100 beats / min - the resistance of the cable is simply not high enough.
Furthermore, I had hoped for a slightly looser sound training, the slide "by surprise" but relatively loud with his hard Kunstoffrollen by rail. Also the latex rope are some train movements loud squeaking noises of itself - that is rather not a sports equipment with you in a rented apartment can still push a training session during the siesta.
The issue raised in other reviews "Hiking" of the device I can confirm also the inferiority of a rubber mat in my case brought only limited success.