1. Not using tempo
Tempo is a key variable to training and it is imperative to success. There is a world of difference between a repetition done with a 4 seconds lowering phase and a pause vs a high speed swing rep. To truly gauge the effectiveness of a program on strength and hypertrophy development you need to carefully measure and record each training variable. Use the correct tempo for each lift for the best results.
2. Too much focus on isolation exercises
Isolation exercises certainly have their place in a training program and can be useful for correcting muscular imbalances and bringing up weak points. However they should never make up the majority of your training program and at most should make up only 20% of your program for the vast majority of training goals. Focus on the big compound exercises like chin ups, dips, squats and dead lifts for the best results.
3. Using too many high repetition sets
Just like isolation exercises high repetition sets definitely have a place in a training program however they are not the best option for most goals. Most people would get better results from training if they alternated between higher and lower rep programs, with a middle point of around 6-8 reps. This would help them change their body composition rapidly and develop strength which is very useful for future high repetition work.
4. An imbalanced training program
How many times have you gone to the gym on bench press monday? And back again for arms day tuesday? and then the same training sessions occur on friday and saturday as people try to 'pump up' for the weekend. Unfortunately this leaves the majority of muscle at the back of the body woefully under-trained. Ideally you would have one pull exercise for every push, one hip dominant exercise for every quad dominant and one set of back work for every abdominal set. Although this is not by fat a perfect approach it is far better than most stuff seen in gyms daily.
5. Program hopping
We all know the person. Each and every week they are starting a new program that is going to finally get them the results they crave. Then the next week, they start the next program. This is a cycle that can lead to nothing but disappointment and crap results. Pick a program and stick yo it for the recommended duration. Assess you results and then try something else. Who knows, you just may find what works for you!
Don't be that guy (or girl). Stop making these mistakes and get something out of going to the gym.
Paul Meldrum has been training clients for over 10 years. He specialises in fat loss, muscle gain and rehabilitation. He was the winner of the 05/06 Personal Trainer of the year award. To receive his 3 part video series on the 8 Things you need to know to lose fat http://dchealthperformance.