It's a great day when someone decides to buck the statistics, reject the easy path, and throw themselves into the challenge of getting strong and healthy, but that's just the beginning. Building the foundation of a fit life takes weeks—months, even—of hard work, and your enthusiasm can often work against you.
Luckily, there's nothing new under the fluorescent lights of the gym. Every mistake you could possibly make has been made a thousand times before, and you can learn from the past

The following are the common mistakes made by the beginners.

Skipping a warm-up and avoiding strength training and flexibility training are common workout mistakes.

Warming up helps prime your nervous system for exercise, helping you prevent skipped heartbeats and premature fatigue. This is especially important if you'll be doing high-intensity exercises, which may lead to injury if you're not properly warmed up.

Ignoring the advice of fitness trainer.

If you're not sure how to best exercise to reach your fitness goals (whether they be to lose weight, build strength, improve performance, or otherwise), a qualified fitness trainer can be invaluable. He or she can guide you in a fitness program that will be the appropriate intensity and duration to help you meet your goals while avoiding injury

Over assuming. Great things take time.

Since breaking and rebuilding of muscle is a very slow process. When you first start out exercising, you may fall in to the trap of assuming that the more often you do it, the faster you'll see results. But overdoing it at the start is a key cause of injury and burnout. Not only is it important to start slow and build your intensity gradually, but it's also important to give your body adequate time for recovery.

Running is not the only form of cardio.

There's nothing inherently wrong with long distance running or aerobics (unless you overdo it), but there are far more efficient and effective forms of cardiovascular training. High-endurance training, such as running for an hour at a time, puts extraordinary stress on your heart. And while stressing a muscle usually makes it stronger, extremely high stress can have the opposite effect—and when it comes to your heart muscle, this can be bad news.

Beginners should do these things in gym.

Running, Treadmill. 1 set, 5-10 minutes.
Leg Press. 1 set.
Lying Leg Curls. 1 set.
Wide-Grip Lat Pulldown. 1 set.
Butterfly. 1 set.
Triceps Pushdown - Rope Attachment. 1 set.
Machine Bicep Curl. 1 set.
Machine Shoulder (Military) Press. 1 set.

Beginners diet

Meal 1. Oatmeal. 1 cup. Egg Whites. Banana. Orange Juice. 8 oz.
Meal 2. Chicken (breast) 8 oz. Brown Rice. 1/2 cup. Mixed Greens. 1/2 cup.
Meal 3. Granola Bar. Apple (small) Milk (skim) 12 oz.
Meal 4. Tuna. 1 can. Apple Cider. 1 can.
Meal 5. Protein Shake.