Warm Up. There are many schools of thought about warming up, however it is generally accepted that warming up muscles that will be used for a specific activity is a good way to avoid injuries such as muscle tears. A good warm up routine to use is to perform the activity you’ll be doing at about 1/3 to ½ the speed or intensity for 5 to 10 minutes.
There are more health claims made about vitamin D than perhaps any other vitamin. Media stories touting vitamin D for this ill or that are common, particularly in the age of COVID-19. We’re also frequently told Americans don’t get enough vitamin D, with surveys showing as many of 40% of individuals have below optimal amounts in the blood. So how do we get vitamin D and what claims are true and backed by research? Let’s take a closer look at vitamin D to flesh out what we know for sure and where more research is needed.
Molecularly, vitamin D is a group of fat-soluble compounds with a four ringed cholesterol backbone. What’s most important to know is that it comes in two forms — as vitamin D2 in food and as vitamin D3 in our skin.
Vitamin D3
Our skin is our primary source of vitamin D, but it begins there as an unorganized and inactive form, requiring UV exposure to convert to usable vitamin D3. Conversion via UV light is exceedingly efficient, and it’s estimated brief exposure of the arms and face is equivalent to ingesting 200 international units day. Conversion varies however with skin type (darker skin converts more), latitude, season and time of day. Infants, disabled persons and older adults often have inadequate sun exposure as well, and the skin of those older than 70 also does not convert vitamin D as effectively. Interestingly, vitamin D also requires temperature to be activated, so you may not get as much of a benefit from sunlight in the winter months as you might expect.
Vitamin D2
Because it is fat-soluble, dietary vitamin D2 is best absorbed with fat in the diet and fish is a common source. Uptake can be negatively impacted by disorders associated with fat malabsorption such as celiac disease, Crohn’s disease, pancreatic insufficiency, cystic fibrosis, short gut syndrome and cholestatic liver disease.
Once activated and in the bloodstream — either by UV exposure or absorption through the diet — the liver converts vitamin D to 25-hydroxyvitamin D (25[OH]D), and then the kidneys further convert it to 1,25 hydroxyvitamin D, the most active form of vitamin D in the body. For this reason, kidney and/or liver problems can also negatively impact vitamin D levels.
Interestingly, all cells in our bodies have receptors for vitamin D, and this has in part fueled the varying claims as to how it might impact health. What we know for certain is that it helps with calcium absorption in the gut, regulating calcium levels via the kidneys, and regulating parathyroid hormone. Vitamin D’s role in calcium regulation and absorption means it has a direct impact on healthy bone growth and turnover. For this reason, you often see it in calcium supplements.
Research has also shown a clear correlation between Vitamin D and muscle health, including research showing improved lower body strength. Some research has also shown vitamin D can help prevent falls in the elderly.
Naomi L. Albertson M.D. is Board Certified by the American Academy of Family Physicians and specializes in the non-surgical management of musculoskeletal problems, sports injuries, concussions, and the treatment of osteopenia and osteoporosis.
Ketosis is a metabolic state similar to starvation in which energy is provided primarily by high fat intake, adequate protein intake (1 gram/Kg lean body mass) and low carbohydrate intake. The idea is to switch your body to using fat as fuel, instead of the usual carbohydrates. The keto diet has traditionally been used for weight loss, but now some athletes have taken up the diet as well.
Carbohydrates are initially restricted to 10 grams per day (15 to 20 grams per day in adolescents and adults), with patients counseled to increase their use of high fat foods (at the expense of protein). Traditionally, the diet consists of four parts fat to one part protein and carbohydrate (i.e., a 4:1 lipid to non-lipid ratio). Total calories are restricted to 80 to 90 percent of recommended values for age (Kossoff et al., 2009). By eating a diet like this, the body becomes very efficient at utilizing fat for energy and produces higher levels of ketones (acetoacetate, acetone, and beta-hydroxybutyrate).
Traditionally athletes have used carbohydrate sources such as maltose, dextrose, and others. The entire industry of sports performance supplements has been geared to maximize carbohydrate absorption (max is about 240 kcals/hour due to GI function/absorption) and items are packaged in 80-100kcal/use servings. So what happens to performance when you athletes switch to a keto diet?
Several studies have been completed looking at the short and longer (up to 3 months) use of keto-diets on performance. The results show ketosis seems to be better suited for endurance athletes than anaerobic athletes. In one study, short-term low-carbohydrate, ketogenic diets reduced exercise performance in activities that are heavily dependent on anaerobic energy systems (wroble, et al,m 2018). In another, a low carb/keto-adaptated group of athletes had improved exercise training, lower body fat, improved fat oxidation during exercise, and better 100km time trial (McSwiney et al., 2018).
The bottom line is more research is needed, however, depending on the athletic activity, the keto diet may either help or harm athletic performance.
Contraindications: Individuals with inborn metabolic errors should NOT use the ketogenic diet. Individuals with a history of documented myopathy or rhabdomyolysis should complete a more in depth workup for inborn errors prior to starting a ketogenic diet due to an increased risk of catabolic crisis.
Naomi L. Albertson M.D. is Board Certified by the American Academy of Family Physicians and specializes in the non-surgical management of musculoskeletal problems, sports injuries, concussions, and the treatment of osteopenia and osteoporosis. A graduate of Tufts University School of Medicine, Dr. Albertson’s interest in bone health, exercise physiology and maximizing performance led her to develop Dr. Ni’s OC2, a bone health and muscle strength supplement for the unique frame support needs of adults over age 35. Visit her website, boneandmuscle.com.
References
Long trusted by athletes and bodybuilders to help improve athletic performance, the muscle strength supplement creatine remains either unknown or shrouded in myth among the wider population. But increasingly creatine is being recognized by the medical community for the benefits it can bring beyond just athletic performance. From assisting in injury recovery to helping reduce the risk of falls in the elderly, creatine is a natural, safe, and effective tool all of us can use…
When you think about staying healthy with age, your bones may not be at the top of your concerns. Age-related bone loss is not generally as obvious as changes in other areas such as our vision or our muscle strength. But a staggering 40% of Americans over age 50 have low bone density, and many people don’t realize they have a problem until they actually break a bone. This will happen to over half of women over age 50 at least once in their lifetime. And despite the common assumption that men don’t need to worry about osteoporosis, a quarter of men over age 50 will suffer an osteoporosis-related break in their lifetime as well. In fact, men are more likely to suffer a fracture from osteoporosis than they are to get prostate cancer.
Bone fractures after age 50 can be serious and disabling. And with a quarter of all hip fractures in people over 50 resulting in death within one year, bone health should be a serious concern for everyone as we grow older.1
So what happens to our bones as we age, and what steps can we take keep our bones healthy?
Bone density changes with age
We often think of bones as hard and lifeless, but they are actually living and changing structures that are constantly reforming and recycling themselves, taking away old minerals and replacing them with new minerals. Calcium and magnesium play a key role in the growth and formation of bone, helping us achieve peak bone mass between the ages of 18 and 30. The more bone you have at the time of peak bone mass, the less likely you are to break a bone or get osteoporosis later in life. After you reach peak bone mass, the balance between bone formation and bone loss might start to change. You may start to slowly lose more bone than you form. In midlife, bone loss usually speeds up in both men and women. For most women, bone loss increases after menopause, when estrogen levels drop sharply. In fact, in the five to seven years after menopause, women can lose up to 20 percent or more of their bone density. The result is that bone becomes weaker and more fragile, and more likely to break from even minor impacts.
How you can help keep bones healthy
Eating a healthy and varied diet with adequate vitamin D3, calcium and magnesium for bone formation is essential. You can find recommendations for your age and gender on the National Osteoporosis Foundation’s website (nof.org).
Exercise is also critical. Strength training to keep muscles strong can help limit falls, which in turn can help prevent resulting fractures. Current exercise recommendations are to do at least 15-30 minutes daily of high impact, weight bearing exercises such as dancing, hiking, jogging/running, jumping rope, stair climbing or tennis. Low-impact weight-bearing exercises can also help keep muscles strong and are a good alternative if you can’t do high-impact.
Smoking and alcohol also impact bone health. Avoid smoking and limit alcohol intake to less than three drinks a day.
Talk to your doctor
There are many additional risk factors for osteoporosis, such as ethnicity, diseases such as rheumatoid arthritis, and medicines you may be taking. So it’s important to discuss your risk with your primary care physician BEFORE you have a fracture. If warranted, your doctor may recommend a test called a bone density study or DXA scan. If you are diagnosed with osteoporosis or osteopenia (a condition of low bone density pre-osteoporosis), your physician may recommend changes to your diet, supplementation, and possibly medications.
For more information to help you take charge of your bone health, check out the National Osteoporosis Foundation at www.nof.org.
Naomi L. Albertson M.D. is Board Certified by the American Academy of Family Physicians and specializes in the non-surgical management of musculoskeletal problems, sports injuries, concussions, and the treatment of osteopenia and osteoporosis.
References