Morphing your physique from soft and flabby into hard and muscular will reward you with more confidence, better physical health and less stress, but it will require true dedication and willpower. A common misconception is that you can hit the gym, pile up the weight and create the body you want. You'll need to combine healthy eating with fat-burning aerobic exercise and muscle-building strength training to get solid, lasting results.

Nutrition

Ditch liquid calories that come from soda, alcohol, specialty coffees, energy drinks and sugary juices. Focus on drinking at least eight 8 oz. glasses of water per day. Water helps keep your body hydrated while eliminating unnecessary calorie intake.

Make smarter snack choices in between meals. Opt for nutrient-dense foods like fruits and vegetables instead of chips, cookies or ice cream. Nutrient-dense foods are high in vitamins, minerals and antioxidants without the added fat, calories and sugar.

Choose whole-grain products over those made from refined flour. This includes pasta, cereals and bread. Whole-grain products are higher in fiber and more digestible.

"Choose a variety of lean protein foods," advises the President's Council on Fitness, Sports & Nutrition, naming meat, poultry, seafood, dry beans or peas, eggs, nuts and seeds as sources of protein. "Select leaner cuts of ground beef (where the label says 90% lean or higher), turkey breast, or chicken breast," the council recommends.

Physical Activity

Warm up with light activity before each workout. Keep it simple with exercises like jumping jacks, jogging in place or arm circles. The goal is to spend about five minutes moving around to gradually increase the blood flow to your muscles.

Build muscle with strength-training two to four times a week. You can focus on two or three muscle groups per day or alternate between upper body and lower body workouts. Let your muscles rest for at least 48 hours before training the same muscle group to avoid injury.

Use weights that challenge your body for muscle growth. You should be using a weight with which you can complete at least six repetitions but no more than 12. If you are not able to tire out your muscles within 90 seconds, increase the amount of weight you are using.

Mix up your routine. Try new exercises and switch between weighted machines and body-weight exercises to avoid hitting a plateau in your results. For example, if you are focusing on your chest muscles in a workout, alternate between push-ups and barbell chest presses.

Perform at least 150 minutes of cardio exercise each week. Split this time up over several days a week. You can work at a moderate pace for longer periods of time. For example, you run can for 40 minutes or do interval training for shorter periods of time -- alternating between a slow or moderate pace and a fast pace.