Acsm and Osteogenic Exercise Recommendation to Prevent Osteoporosis

In a society with higher rates of older population and longer life span over time, the prevalence of multiple degenerative disease is increasing. Nowadays, there is a high incidence of osteoporosis compared to other common disease states, such as: heart attacks, strokes, cancers, etc. The rates of osteoporosis, situate this degenerative diseases as one of the most common bone disease within aging, and a clear challenge to our global public health. However, osteoporosis does not have a clear definition and cause, it is typically something that happens as we age that lead us to such diagnosis. There is not a set of symptoms that define osteoporosis, both males or females can be identified as osteoporotic. Specially, when they develop a fracture, which is considered a minimal trauma, in consequence to an increased loss of bone mass and strength. Furthermore, one of the most preventing sings that a person may have osteoporosis, it is the development of spinal fractures that occur with chronic back pain, but that is often confused for muscle strain. Osteoporosis is basically a “silent disease”, until those fractures or such intense spinal pain occur, which can lead to severe secondary health problems or even death among older population. Because, fractures are associated with an increased morbidity and mortality, meaning an increased risk of infection, death and other problems associated with a fracture. Unfortunately, that is how most old people in EEUU gets diagnosed with osteoporosis, they have an incident with a broken bone, which typically leads an individual to be diagnosed as osteoporotic. In consequence, as the population ages, Osteoporosis is increasingly affecting a tremendous amount of people in our society. Meanwhile, independently of race and gender, the number of individuals aged 50+ with osteoporosis increase over 20 million persons, just in the US. Therefore, it is very important to identify and treat people at risk. In order to prevent all those spine, hipe and all types of fractures, which would negatively alter a natural aging process.

Osteoporosis doesn't happen overnight, it is a highly complex multifactorial pathology. Some of these factors include: age, gender, behavioral activity, dietary patterns, physical activity (PA), family history, etc. In essence, all these factors interplay in a vicious cycle that would eventually increases the likelihood of developing osteoporosis in old age. The primary combination for low peak bone mass is constituted by hormone (estrogen), calcium and vitamin D deficiency, sedentary lifestyle, and advanced aging. However, when we are talking about osteoporosis in older adults, we do not want to focus on the negative impact that estrogen deprivation has on postmenopausal females and their rapid decline on bone mineral density (BMD) after that hormonal stage. In older population and how the aging process affects osteoporosis or vice versa. We are looking at a more gradual and progressive age-related bone loss, which includes both males and females. During the early ages, most people is able to naturally resorb and from new bone density, until they hit their peak BMD between their 20 and 30 years of age. Then, they go through a few years of plateau that would lead to a constant decline in total BMD. Because, as we age our ability to regenerate old bone with new bone decreases over time, along with its overall strength and stiffness levels. Basically, as we age we experience an acceleration in bone loss, that consequently can lead to osteoporosis. So, the multiple mechanical functions, such as: body support, facilitation of movement, storage of minerals, etc. That our skeletal system should be able to do and maintain during our entire life span at some minimum degreed, even as we age. Due to osteoporosis and its respective degenerative consequences, those mechanical functions are going to be negatively affected and thus, accelerate the aging process. Therefore, the negative effects that osteoporosis has on older population and the process of aging. This can affect the exercise ability of older individuals, which would consequently lead to exercise deficiency. And that can worsen the PA situation for the person and thus, contribute on the develop of osteoporosis. Because, exercise is a great contributor to address BMD and bones are very adaptable structures. In order to enhance bone density and created greater structural skeletal adaptations, we need to stress them before we reach that peak in BMD and we start to experience that constant drop in BMD as we age.

Physical activity has been identified as a number one strategy to address bone mineral density loss, which is one of the major leading causes to develop osteoporosis as we age. Therefore, we want our entire population to exercise, so they can reach the highest peak of BMD as possible, and when they start to experience the aging process and the respective decline on BMD, the starting point of such decline would higher. However, the American College of Sports Medicine (ACSM) guidelines for general exercise - ACSM = Cardio 5/day, moderate intensity, 30-mins per session, 150-min per week: Weight training: two days per week, 10 exercises, 1-2 sets at 8-12 reps. - are completely different to the principles that govern Osteogenic, which basically relates to the formation of bone. Because, not all physical activity qualifies as being Osteogenic. Hence, when we ask older individuals to exercise, it actually has a purpose behind, we want to evoke an hormone response on their system. And exercise intensity is the main contributor factor; due to in response to such alterations in the skeletal system, bone growth and strength will be positively enhanced. However, the ACSM recommendations in older individuals, are actually to favor low intensity exercise. Which, in consequence will never distress the skeletal system and nor evoke such hormonal response that would increase bone growth and as a result prevent osteoporosis as we age. There is a huge difference, in terms of what the ACSM guidelines recommend, what Osteogenic exercise consists, and the incorporation of mechanical load in older individuals to enhanced bone growth and strength. Therefore, if we are going to do Osteogenic exercise and truly benefit from it, we have to make sure that whatever exercise we do, it has to stimulate the body, distress the skeletal system, through some type of intensity in order to get a hormone response. Because without a hormone response, like the growth among others, those hormones help to stimulate anabolic mechanisms associated with bone growth. Thus, we have to do higher intensity exercise and we have to make sure we incorporate ground reaction forces, those are two key things in order to prevent osteoporosis in older population.

The controversy between ACSM and Osteogenic exercise recommendation rises a few limitation, considering that older individuals that are going through a progressive and degenerative aging process, their systems are not going to be able to perform the same activities that younger individuals would, in terms of frequency and intensity. If we follow osteogenic principles we will get a higher intensity and greater ground reaction forces with running, than we would in terms of the ACSM recommendations, like walking. There is nothing wrong with walking, it is a very healthy activity and it has been shown to have multiple benefits for older people; such as: mobility, lower risk of cardiovascular diseases, reduce anxiety, etc. However, in terms of bone growth and osteoporosis prevention mechanism, there are some limitations with it. Obviously, the action of walking implies some ground reaction forces, but these are just not happening with an intensity high enough to put stress on the skeletal system. Furthermore, Osteogenic exercise requires 36 cycles as we can achieve with HIT, compared to the ACSM recommendations asking older people to only do 1-2 sets of 8-12 reps, which is 16-24 cycles in a normal lift session. So, by asking them to only do 1-2 sets of 8-12 reps, it is not enough to be above the bones yield point. Threofore, following the ACSM recommendations we would be below that point because of not getting enough exercise cycles. Thus, we see again how the osteogenic exercise is widely different than what the ACSM recommends. Moreover, in order to have an effect in BMD, Osteogenic exercise requires unusual and different exercises in orientation and magnitude. This is why, once again activities like walking, wouldn't be classified as an osteogenic exercise. Also, if we do low frequency exercise with strength training, that is not going to help in terms of osteogenic exercise either. But, even if we do high frequency and high intensity exercise in older populations, we run the risk of imposing musculoskeletal injuries. And, that is a risk that we also need to avoid. Therefore, we must think in which way we want to go, in terms of exercise implementation; the low frequency high intensity following a high interval training (HIT) paradigm, just as osteogenic exercise recommends. However, if we go back to the ACSM recommendations, we discovered that in older populations we don't see HIT as a motive exercise. The ACSM repeatedly mentions exercise like tai chi, walking along other activities that doesn't imply the needed forces impact, to stress the skeletal system and evoke an adaptation in bone growth.

To conclude, there is a huge contrast between the ACSM recommendation and the osteogenic exercise. We have to think about strength at greater frequencies, that is comparative from doing nothing or it is greater than what is the person's normal base activity. However, regardless of any exercise recommendation, if older individuals do not meet a basic nutrient base, with excess calcium and vitamin D, approached to maintain a healthy hormone profile, we are going to have difficulty maintaining BMD and thus, engaging in Osteogenic exercises and its impact on BMD will not be as effective as it could be. Finally, another important factor would be the emphasis on balance improvement during aging, which must include very simple activities that older individuals can easily perform at home. Because, increasing balance levels in elderly population can potentially decrease the number of falls. Which as previously mentioned, fall is one the main causes to hip fractures and diagnosis of osteoporosis in older individuals.