Hitting the pause button during the execution of a program in "debug" mode might not provide the right data to perform any performance optimizations. To put it bluntly, it is a crude form of profiling.
If you must avoid using a profiler, a better bet is to use a logger, and then apply a slowdown factor to "guesstimate" where the real problem is. Profilers however, are better tools for guesstimating.
The reason why hitting the pause button in debug mode, may not give a real picture of application behavior is because debuggers introduce additional executable code that can slowdown certain parts of the application. One can refer to Mike Stall's blog post on possible reasons for application slowdown in a debugging environment. The post sheds light on certain reasons like too many breakpoints,creation of exception objects, unoptimized code etc. The part about unoptimized code is important - the "debug" mode will result in a lot of optimizations (usually code in-lining and re-ordering) being thrown out of the window, to enable the debug host (the process running your code) and the IDE to synchronize code execution. Therefore, hitting pause repeatedly in "debug" mode might be a bad idea.
