In Wescott's study 'Resistance Training is Medicine', he states: Not long ago, the muscle-building activity known as weight training generally was considered to be the domain of exceptionally strong men who competed in sports such as powerlifting, Olympic lifting, bodybuilding, and football. [...] Average individuals saw no reason to engage in weight training, and participants in other sports typically felt that lifting weights actually would hinder their athletic performance.
As American lifestyle became more sedentary and heart disease became the leading cause of death, regular exercise was promoted for attaining physical fitness, desirable body weight, and cardiorespiratory health. However, the overwhelming emphasis was on aerobic activity with little encouragement for resistance training.
He then writes; The series of events that seem to be associated with a large number of illnesses, injuries, and infirmities are 1) muscle loss, 2) leading to metabolic rate reduction, 3) followed by fat gain that places almost 80% of men and 70% of women 60 years of age and older in the undesirable categories of overweight or obese. These percentages are based on body mass index calculations that do not account for age-related sarcopenia. It is therefore likely that an even higher percentage of the older adult population has excess body fat (above 22% for males and above 32% for females).
Wescott states that strength training can increase muscle gains in men and women of all ages and that:
Numerous studies have demonstrated that relatively brief sessions (e.g.,12 to 20 total exercise sets) of regular resistance training (two or three nonconsecutive days per week) can increase muscle mass in adults of all ages through the 10th decade of life. Alongside this he describes how strength training can actually help decrease or reverse some of the listed events above leading to or associated with illnesses and injuries.
This review provides evidence that resistance training is effective in enhancing several important aspects of physical and mental health. Beginning with the progressive reduction in muscle mass and resting metabolism associated with inactive aging, resistance training studies have consistently demonstrated significant increases in lean weight and metabolic rate, accompanied by significant decreases in fat weight. In the multiple areas that involve physical performance, resistance training has been associated with reduced low back pain, decreased arthritic discomfort, increased functional independence, enhanced movement control, and increased walking speed. Based on numerous studies that showed improved glucose and insulin homeostasis, resistance training has been recommended for resisting type 2 diabetes. With respect to cardiovascular health, resistance training research has demonstrated reduced resting blood pressure, improved blood lipid profiles, and enhanced vascular condition. Resistance training appears to have greater impact on bone density than other types of physical activity and has been shown to significantly increase BMD in adults of all ages. The demonstrated mental health benefits of resistance training have included decreased symptoms of depression, increased self-esteem and physical self-concept, and improved cognitive ability. Finally and fundamentally, resistance training has been shown to reverse aging factors in skeletal muscle. (1)
That said, strength training is not just for athletes. In fact, it's beneficial for all of us, including the elderly.
Strength training in the elderly (>60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength.[...] Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function
The less active a person’s lifestyle, the earlier age-related changes will manifest. A reduction in motor capacity and visual and vestibular skills are foremost among these changes. In addition to a reduction in muscle fibers (type 1 and especially type 2 fibers, especially in the lower extremity), the responsibility for this lies with neuronal factors (a reduction in spinal motoneurons or spinal inhibitions) and impairments to mechanical muscle function (such as for example reduced maximum frequency or reduced elasticity).
Muscle strength gradually decreases from the 30th year until about the 50th year of life. In the 6th decade of life, an accelerated, non-linear decrease by 15% has been observed, and by the 8th decade, this may be up to 30%. This additionally results in a substantial impairment in the sensorimotor information exchange, with a reduction in the quality of intermuscular and intramuscular coordination. Functional losses in strength and balance capacity, and increasing gait uncertainties are the result. The risk of acute problems owing to falls and injuries and chronic recurrent and degenerative illnesses rises.
Several studies have shown that strength (resistance) training can counteract age related impairments. The crucial factor in maintaining strength capacity is an increase in muscle mass. Additionally, an increase in muscle activity and frequency during isometric and dynamic muscle work have been observed. (2)
So, we've established that lifting is good.
Even if you're not a bodybuilder. Or an athlete. It's really really good for health. So why don't people lift more often?
There's a general myth that lifting weights will make you "bulky" which can put people off, especially, historically, females.
How likely is it that you will become massive once you start lifting weights?
Not very likely. Bulking up is hard and requires a lot of thought into nutrition and training. If you lift weights you will get stronger but that doesn't mean you will look like the Hulk. Many endurance athletes follow strength and conditioning programmes and engage in strength work to compliment their sport, not with the aim of 'bulking up'. They are becoming robust, preventing injuries and working on weaknesses to enhance performance in their specific sport.
So, from a health perspective, no matter who you are and what you do, strength training is awesome and, in most cases, hugely beneficial!
Go on..give it a try...