Strength training is a great complement to an aerobic exercise program. It’s good because of the added benefits that occur. Resistance training increases muscle strength and endurance by up to 100 percent or even more, and interestingly enough, the greatest improvements have been reported in elderly or frail adults.Strength training helps maintain or increase lean body mass, and muscle mass burns calories. That helps with weight control.

There are 3 main types of exercise: aerobic exercise, strength training, and stretching. All are important for good health.Aerobic exercise works the heart and gets your muscles to use more oxygen. After a time, your heart will get stronger and able to deliver oxygen to your muscles more easily. This is what is known as "getting into shape." If you need to, start gradually. If weight reduction is your goal, it is important to focus on doing some type of aerobic activity most days, plus adding a few days of strength training.When you work your muscles, they become stronger and able to work longer without getting tired. Stomach muscles support the back, so strengthening this area is really important.

Increased physical activity can increase the mass, strength, endurance, and power of muscles. Strength training induces increases in maximal concentric (the contracting muscle shortens), eccentric (the contracting muscle lengthens) and isometric muscle strength, as well as in the rate of muscle force development during contraction.The effects on morphology and performance of muscle training are most needed in elderly people with various degrees of sarcopenia and its consequences.

Strength training for kids, however, isn't about lifting the heaviest weight possible. Instead, the focus is on lighter weights and controlled movements, with a special emphasis on proper technique and safety.Your child can build muscle strength using:

• Free weights
• Weight machines
• Resistance bands
• His or her own body weight

There are many different methods of strength training, the most common being the use of gravity (see weight training) or elastic/hydraulic (see resistance training) forces to oppose muscle contraction. As we get older, our body mass changes, and strength training can help us maintain a leaner body as we age. Moreover, it can improve glucose metabolism and the way our bodies handle sugars. It may also improve the overall cholesterol profile by modestly lowering LDL (“bad”) cholesterol and triglycerides and raising HDL (“good”) cholesterol levels.

Sarcopenia can be defined as the age-related loss of muscle mass,strength and function. In one study, moderate to severe sarcopenia (muscle mass two standard deviations or more below the sex-specific mean for young adults) was found in 10% of women and 7% of men 60 years or older .With aging, sarcopenia also decreases metabolically active muscle tissue and leads to increased fat mass, without concomitant change in body mass.Exercises that stretch and strengthen the muscles of your abdomen and spine can help prevent back problems. If your back and abdominal muscles are strong, you can maintain good posture and keep your spine in its correct position.

Strength training has many more benefits including

• Burn more calories: Your base metabolic rate can stay elevated 18 to 24 hours after a strength workout (even higher and longer than an aerobic workout). This means that your body burns calories at a faster rate long after you are done lifting weights.
• Weight loss: You lose unhealthy body fat while sparing good lean muscle mass.
• Strong bones: Weight bearing exercise increases bone density. This decreases your risk of having osteoporosis.
• Better insulin sensitivity: Your body is able to control your blood sugar levels with less insulin and puts less stress on your pancreas. This is particularly beneficial for people with diabetes.
• Lower cholesterol: Training helps lower LDL (bad cholesterol) levels and triglyceride levels and raise HDL (good cholesterol) levels.
• Lower blood pressure: Strength training lowers your blood pressure and help your heart work better.
• Mood: Your alertness, energy, overall attitude, and sex drive is likely to improve.

A study of 164 overweight and obese (BMI 25-35) Minnesota women 24 to 44 years old found that strength training with weights dramatically reduced the increase in abdominal fat in premenopausal participants compared to similar women who merely received advice about exercise.The strength training reduced intra-abdominal fat, which is more closely associated with heart disease and metabolic disturbances.This study shows that strength training can prevent increases in body fat percentage and attenuate increases in the fat depot most closely associated with heart disease.

Loss of muscle tissue begins in the fourth decade of life and accelerates after the age of approximately 75 years. By age 50, most people will have lost about 10% of their muscle mass, and by age 70 they will have lost about 40%. Muscle strength is lost in about the same proportions. Most atrophy is seen in fast twitch fibers and loss is most obvious in physically inactive individuals, but it is also evident in persons who have been continuously physically active throughout their lives.Lack of sufficient muscle strength causing pull and torsion in the bones accelerates bone loss and increases the risk of osteoporosis.

If you do develop an injury, your doctor may suggest particular strengthening exercises. Every day you should do 3 sets of each exercise, with 10 repetitions in each set. For the exercises that involve straight-leg raises, you will want to add ankle weights as the exercises become easier for you. These exercises may also be done as part of your overall exercise program.

Strength training, which increases muscle and reduces fat, may also be helpful for people with diabetes.Strenuous strength training or high-impact exercise is not recommended for people with uncontrolled diabetes. Such exercises can strain weakened blood vessels in the eyes of patients with retinopathy. High-impact exercise may also injure blood vessels in the feet.

Strength training may not only make older adults' muscles stronger, but younger as well, a small study suggests.

It's well known that resistance exercises improve muscle strength and function in young and old alike, but the new research suggests that strength training also affects older muscles on the level of gene expression -- essentially turning back the clock on muscle aging.

The study, published in the online journal PLoS One, looked at whether strength training affects the "gene expression profile" in older adults' muscle. Genes hold the instructions from which the body manufactures proteins; gene expression refers to the processes that translate these instructions into proteins.

Analyzing small samples of muscle tissue from a group of healthy young and older adults, researchers found that older and younger muscle tissues differed significantly in their gene expression profiles. The difference indicated that older muscle tissue had impaired functioning in mitochondria -- structures within cells that act as the cell's "powerhouse."

That impairment was reversible, however. After 14 of the older adults underwent 6 months of strength training, the gene expression profile in their muscles showed a more youthful appearance.

"In a very real sense, the muscle was younger," said lead study author Dr. Simon Melov of the Buck Institute for Age Research in Novato, California.

Experts have long known that exercise is good for younger and older adults alike, Melov told Reuters Health, but the new findings suggest that it can "actually rejuvenate muscle" in older individuals.

The study included 25 healthy men and women older than 65, and 26 healthy adults ages 20 to 35 who had diet and exercise habits similar to the older group. By analyzing muscle tissue from each volunteer, Melov's team found age-related differences in the expression of hundreds of genes -- such that mitochondrial function in older adults appeared "dramatically impaired."

Fourteen of the older adults then went through a strength training program, working out two days a week for 6 months.

As expected, the researchers found that these volunteers boosted their muscle strength, coming closer to their younger counterparts' performance. But their muscle also showed a turnaround in gene expression that Melov described as surprisingly stark.

He said more studies are needed to see whether aerobic exercise, like walking or cycling, has similar effects on muscle -- and whether exercise might reverse molecular aging in other types of body tissue.

For now, the researchers say, their findings show that it's never too late to start exercising.

A recent double-blind, placebo-controlled study involving 27 women and 34 men, 68 to 88 years of age, who were given growth hormone or placebo for 6.5 months confirmed the effects of growth hormone on body composition; there was no change in muscle strength or maximal oxygen uptake during exercise in either group.This study corroborated the findings of a study by Papadakis et al. involving 52 healthy men, 70 to 85 years of age, who were given placebo or growth hormone for six months. Not mentioned on the "antiaging" Web sites is a study of 18 healthy men, 65 to 82 years of age, who underwent progressive strength training for 14 weeks, followed by an additional 10 weeks of strength training plus either growth hormone or placebo. In that study, resistance exercise training increased muscle strength significantly; the addition of growth hormone did not result in any further improvement. Going to the gym is beneficial and certainly cheaper than growth hormone.

A single set of strength training exercises can build muscle as effectively as multiple sets. This has been reported in scientific literature for a number of years. But the "tradition" of three sets or more doesn't die easily.In 1998, an analysis of multiple previous studies compared single-set and multiple-set strength training. Thirty-three out of 35 studies examined showed no significant difference between single sets and multiple sets in regard to strength gains or lean muscle mass increases. Another study found that using a weight sufficient to fatigue the muscle at about 12 repetitions is optimal stimulus for strength gain.

Another study shown that Muscle strength significantly improved in the experimental group for strong side muscle groups (ranged from 23.9% to 36.5%) and paretic side muscle groups (ranged from 10.1% to 77.9%). In the control group muscle strength changes ranged from 6.7% gain to 11.2% decline. The experimental group showed significant improvement in all selected measures of functional performance except for the step test. In the control group, the number of repetitions of the step test significantly decreased (-20.3%) with no change in other functional tests. There was a significant difference between groups for muscle strength and all functional measures. The strength gain was significantly associated with gain in the functional tests.

Despite its reputation as a "guy" or "jock" thing, strength training is important for everyone. With a regular strength training program, you can reduce your body fat, increase your lean muscle mass and burn calories more efficiently.