4bda57919c
.. when looking for efforts in a workout that are at or above the limit of the athlete we stopped as soon as we found a section that was too hard. .. we now keep looking for impossible sections since there are often multiple hard efforts hidden within a longer section. .. there does not seem to be any considerable performance overhead with this approach.
GoldenCheetah
About
GoldenCheetah is an open-source data analysis tool primarily written in C++ with Qt for cyclists and triathletes with support for training as well.
GoldenCheetah can connect with indoor trainers and cycling equipment such as cycling computers and power meters to import data.
In addition, GoldenCheetah can connect to cloud services.
It can then manipulate and view the data, as well as analyze it.
Installing
Golden Cheetah install and build instructions are documented for each platform;
INSTALL-WIN32 For building on Microsoft Windows
INSTALL-LINUX For building on Linux
INSTALL-MAC For building on Apple OS X
OSX: 
Windows:
Alternatively, official builds are available from http://www.goldencheetah.org
whilst the latest developer builds are available from https://github.com/GoldenCheetah/GoldenCheetah/releases