No one wants to spend more time in the gym getting bad results, or even worse, getting hurt. The first goal of a well-designed training program should be avoiding injury while training. With that in mind, there are common mistakes that too many people make in the gym which prevent them from reaching their desired goals.
Mistake #1 No workout order.  In terms of exercise selection, people often copy regulars at the gym who appear to know what they’re doing. This usually results in random exercises performed incorrectly in a program that is actually non-existent.
The Fix: Learn how to execute exercises correctly, and either learn about program design and exercise selection or have a personal program designed to best fit your needs.
Mistake #2 Program hopping. Jumping from one program to the next isn’t always the best idea either. Changing up training variables (sets, reps, breaks, exercises etc.) from one workout or training phase to the next is referred to as periodization. This variation in training can be great to avoid boredom and staleness but has to be planned to be effective. Randomly changing exercises or program hopping yields improvements in strength and muscular development and isn’t encouraged.
The Fix: Find a well-balanced routine that works for you and stick to it for two to three months. Follow your routines from week to week and re-evaluate. Make slight alterations if you need to but keep the bulk of the program the same and give the routine a chance.
Mistake #3 Wrong mental attitude. Setting foot in the gym and moving some weights around is only half the battle. Having the right mental attitude, determination and discipline will determine if you actually reach those goals. Always strive to be better, resist the temptation to get frustrated and keep at it.
The Fix: Find a workout partner who is slightly stronger or more fit than you. You’ll be able to work off each other and reach levels of fitness you wouldn’t have otherwise. Create a social network with people that have similar goals and ambitions. Stay positive and motivated and the results will come on their own.