How to run a cycle on an arduino without brakes?

Question

Arduino

Hello!
There is an arduino leonardo + gprs shield
there is a main program, spinning in a magnifying glass
, this program starts with the lines

if (gprs.ifcallNow() || digitalRead(ledPin) == HIGH) 
  {....}

The problem is the following - if you leave the existing condition, then the program starts with a significant delay (two, three, five seconds, whatever) If you leave at least one condition (no matter what, activation from a call or from a pin), then everything works quickly (instantly )
Why is it like this, and how to live with it?)

Answer 1

To write such things in a loop, in my opinion, is bad manners. why not use interrupts?