I like to get my workouts done in the morning. It helps to wake me up, I don’t have to worry about fitting it in later, and I feel like I’ve already got one thing checked off my list before the day has really even started. But I’m not always sure whether I should work-out on an empty stomach or eat a little something to fuel the activity.

Admittedly, the choice to eat or not eat before or after exercise and what types of food to choose is a matter of personal preference. If what you are doing feels right for your body, then there may be no reason to adjust your habits. But if you are looking to improve performance or are not happy with your current routine or are just getting started and would like a suggestion, here are a few things to consider.

Our bodies can use 2 fuel sources for energy during exercise: carbohydrate and fat. We burn a combination of the two throughout the day, but in general, fat is burned when we are just sitting around or doing low-intensity activity and carbs fuel more intense exercise. Fortunately, our bodies store both of these macronutrients, which is why we can move even if we haven’t eaten for a while.

We know all about the fat stores in our bodies, but did you know that we store carbs too? Glucose (the main carbohydrate building block) is stored in our muscles as glycogen, which is just a bunch of glucose molecules linked together. We also store some glycogen in our liver, which can be released back to our bloodstream as needed, such as when we are sleeping so our blood sugars don’t drop too low. The glycogen in our muscles can’t go back into the bloodstream, but the muscles can break it down to use for energy themselves.
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The amount of glycogen stored in muscles is directly related to how long it takes for a muscle to get fatigued. If you’ve ever heard of carbohydrate loading, the premise is that a week or several days before an event, athletes train their muscles to store more glycogen, so that while they are actually performing, the muscles have enough energy to sustain the exercise for a longer period of time. However, normal glycogen stores can generally fuel exercise of 60 to 90 minutes with no problem. When our muscles run out of glycogen, they have to rely on glucose coming from the bloodstream, so if your workout is more than an hour, you may need to eat something so those muscles don’t run out of steam.

If I am just jogging for 45 minutes at moderate intensity at the beginning of the day, I don’t need to eat ahead of time because the muscles should have enough glycogen to keep my legs moving that long, right? Honestly, I do it all the time, and I’m fine, however if you haven’t eaten since the night before, your liver glycogen is depleted. With no food coming in, your blood sugar level could be low. Low blood sugar means not enough fuel for the brain, which can cause you to feel tired and lightheaded and can interfere with running for reasons other than muscle fatigue. Therefore, eating a little bit of carbohydrate food, like a banana, or fruit, or toast could be helpful.
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I hear you’re supposed to do yoga on an empty stomach – is that true? As a yoga instructor, I admit to feeling uncomfortable during class if I have eaten a meal too recently. Yoga involves moving your body in lots of different ways. Laying on your belly, twisting, and back bending don’t feel good with a full stomach. However, if you are doing a vigorous practice and haven’t eaten in many hours, low blood sugar could put you at risk of losing your balance or passing out. It’s important in yoga as well as other forms of exercise to balance comfort with safety. You don’t have to eat a lot to perk up your blood sugar – just half a granola bar or a small orange is plenty. When it comes to running, the motion of it can shake things up inside, so eat something easy to digest, low in fiber and fat, both of which can slow digestion. If you’re going for a bike ride, you might be able to eat a heavier or larger meal since your belly will remain relatively stable during the ride. On the flip side, if you are doing a Tabata workout or sprint drills, very high intensity exercise can pull blood flow to muscles and away from the digestive system. Anything you eat may not be able to digest at all causing GI issues as it sits in your stomach.

When I am exercising, I’d kinda like to burn some of that stored fat for fuel. Do I have to have used up all of my glycogen first? Maybe it would be better to eat fewer carbs so that I don’t have a lot of glycogen to start with and my muscles have to use fat. Some studies have looked at this idea to see if a low-carb high-fat diet might cause the body to use more fat stores during exercise, and it kinda works, mainly because you give the body no choice. But turns out that performance fueled by fat rather than carbohydrate is not improved at all, and there are some other negative side effects to a high fat diet. In reality, the type of energy you burn has more to do with the type of exercise you are doing than the type of food in your diet. As I mentioned earlier, we tend to burn more fat with lower intensity exercise such as walking, though the lower intensity also means we burn fewer total calories. Ultimately, creating a calorie deficit each day will burn fat in the long run, whether you are actually burning it during your exercise session or not.
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Okay, but what about a gym training session that involves mostly resistance exercise? Should I do anything different? Muscles are made of protein, so if you’re breaking them down in training, you want them to rebuild. Eating protein before a workout may provide a ready supply of amino acids to replete muscles as they break down. However, you still need carb to actually fuel the muscles, and eating too much protein only causes the body to use it as a fuel source, which is inefficient. So having a small meal or snack that is balanced in carb and protein and low in fat is the standard recommendation.

After a workout, think about trying to replace what you have broken down or used up in the exercise. If you’ve used up your muscle glycogen stores, you need carbohydrate to replete them. If you’ve broken down muscle (which can happen during any exercise in which you are bearing your body weight), some protein can help rebuild it. Chocolate milk is often suggested as the perfect post-workout snack because it offers proteins (casein and whey) as well as carbohydrates (lactose from the dairy and likely sucrose as a sweetener). Here are a few other easy post-exercise options:

• Bagel or toast with peanut butter
• Fruit and Nuts
• Yogurt
• Protein bar
• Crackers or pretzels with hummus
• Hard boiled egg and fruit juice
• Sandwich with sliced meat or cheese

You could also eat a full meal after a workout, ensuring you get enough to replenish your body.

​Athletes training to improve performance may need to be much more deliberate about meal composition and timing. But even if you are a recreational exerciser, eating intentionally before and after a workout may help you to get the most out of it. If you’re going to put in the time, fueling properly could assist you in feeling energized during activity, leading to improved results. And refueling afterwards can support your recovery, helping you to feel great the rest of the day as well.

​My name is Lorelei Sturm. Some of you may know me as a yoga instructor with Chicago’s Neighborhood Fitness Centers. I am also a Registered Dietitian with a Master’s degree in Nutrition. CNF is committed to helping its members lead healthier lives by encouraging wellness and a healthy lifestyle in addition to fitness. So, what burning nutrition questions do you have? Let me know in the comments below. 

​They say low-fat is where it’s at.
Fat-free is even better.
Omit ALL glycerides,
And you’ll look great in that tight sweater.
 
Low-carb’s the way, is what they say.
Eschew all foods with starches.
So skip the bun and French fries
When you patronize the arches.

​They warn that gluten makes you ill
And causes stomach pains.
Take one more step, just to be safe,
And go against all grains.
 
For low BP, no MSG
Or salt should touch your dish.
Though pesticides may taint your greens,
And mercury your fish.
 
Garlic makes your breath stink.
Legumes will give you gas.
Tea has tannins, so does wine.
Don’t pour them in your glass!

​And eggs have high cholesterol.
(Cholesterol is bad)
Meat’s full of saturated fat.
Plus, killing pigs is sad.
 
Dairy is a nightmare
Full of hormones and cow tears.
Beware antibiotics!
No milk can calm your fears.

​Soy increases estrogen.
Most corn is GMO.
There must be something wrong with peas,
But what, they don’t yet know.
 
I’m paranoid, so I avoid
All foods they say might stun me.
I am the queen of eating clean,
But I am really hungry!
                                        Lorelei Sturm

​If you can relate, you are not alone.  When it comes to advice about health and nutrition, there is SOOO much information out there, easily accessible via internet.  Much of it is delivered passionately with a rigid point of view and tons of reasons why what THEY SAY is right and everyone else is wrong.  It is impossible to believe and follow everything all at the same time, but also difficult to ignore advice and suggestions that sound really convincing.
 
Here are a few questions to ask yourself when offered nutrition advice:

• What is the source?  Do they have any credentials that would suggest they know what they are talking about?
• What is their agenda?  Sometimes people are actually selling a product that solves the problem they have brought to your attention – be wary!  Sometimes people just want to be right.  Most people are well-intentioned, or at least they think they are, but it’s worth questioning.
• Do they back up the claim with evidence based scientific research or mere personal anecdote (ie: “my sister tried this thing and it totally worked!”)?  Usually you’ll hear both, and both can be compelling.  When someone sites a study, it can be hard to know without doing a lot of additional research whether or not the study was a high quality peer reviewed process.  But if you’ve ever read any of those top notch articles, they are generally pretty boring and rarely yield mind blowing results.  As for stories about individual experiences, try to take them at face value.  What works for one doesn’t work for all.

 
If you have a hard time distinguishing practical, down to earth recommendations from bogus or simply trendy ones, don’t go online!  Ask your doctor, or better yet, a qualified dietitian.  Doctors can and will give dietary advice, but most get very little nutrition training in medical school.  And look, you probably already know there is no magic bullet when it comes to losing weight or building muscle or living a longer healthier life.  It’s a process of making sensible choices over time.
 

​My name is Lorelei Sturm. Some of you may know me as a yoga instructor with Chicago’s Neighborhood Fitness Centers. I am also a Registered Dietitian with a Master’s degree in Nutrition. CNF is committed to helping its members lead healthier lives by encouraging wellness and a healthy lifestyle in addition to fitness. So, what burning nutrition questions do you have? Let me know in the comments below. 

This coronavirus doesn’t appear to be going away anytime soon, and despite masks and distancing, it seems likely that a high percentage of people may eventually be exposed to it. There may be a vaccine someday, hopefully some drugs and treatments will help with symptoms and keep people from dying. But is there anything that we should be doing nutritionally to keep us from getting really sick? Some medical experts are actually looking into certain micronutrients such as Vitamins C and D and Zinc, so I wanted to share with you my thoughts as a dietitian based on the science.

Many of us have been brought up thinking that Vitamin C can help treat the common cold, leading us to stock up on OJ and EmergenC when we get the sniffles. Studies have actually shown that though people who regularly supplement with Vitamin C may experience fewer days of cold symptoms, they are not less likely to catch a cold, and taking Vitamin C when you first notice symptoms does little or nothing to reduce the length or severity of the illness(1). But it’s pretty ingrained in our belief system, so no wonder many store shelves have been emptied of Vitamin C supplements this season. Zinc is a similar story – lots of people think it helps, but the science isn’t super supportive of that idea. Coronavirus is different from a cold or the flu though, so research is currently being done to see if either could play a role in supporting immunity to keep people healthier. We’ll see!

Vitamin D seems a little more promising at this point. Vitamin D is mainly responsible for maintaining blood calcium levels in the body, but it does a bunch of other things as well, including supporting the immune system and preventing inflammation. Some studies have been done in the past to see if taking Vitamin D might keep people from developing the flu with mixed results(2). However, D has specifically been shown to protect against acute respiratory infections, which is noteworthy considering COVID-19 seems to be attacking people’s respiratory systems.

Our bodies can make Vitamin D when our skin is exposed to sunlight, which is historically how we have met our D needs. Interestingly, most flus including COVID-19 begin to spread during winter months when there is less sunlight. People’s ability to make Vitamin D from sunlight declines with age, so lots of older individuals have low Vitamin D levels, and older individuals also tend to be more at risk for bad outcomes with COVID-19. These parallels could be purely coincidental, but again, researchers want to know if there might be an actual relationship between Vitamin D levels and susceptibility to the virus.
I looked up a few recent studies to understand what the thinking is, and here is what I found:

• A pilot* study done several years ago on ventilated ICU patients found that high dose Vitamin D safely increased blood concentration of the vitamin and was associated with decreased hospital length of stay(3).
• A more recent study found correlations** between low blood levels of Vitamin D and increased severity of coronavirus symptoms, meaning the odds of having a critical outcome increased when blood levels decreased, and vice versa(4).
• An association was identified between average vitamin D levels in various European countries and COVID-19 cases and mortalities. Low vitamin D levels correlated** to more cases and deaths(5).

*pilot studies are a kind of practice, they can’t officially conclude anything
**correlation does not equal causation

The bottom line for these studies is that more studies need to be done. It’s not that they don’t have anything to show for themselves, but usually it is something like “hey, this is what might be happening, let’s come up with a better study to really test this idea.” COVID-19 is very new, so randomized clinical trials (the gold standard), which could test whether or not increasing vitamin D intake could actually benefit infected patients, just haven’t happened yet. However, according to one research team, “Vitamin D has already been shown to protect against acute respiratory infections and it was shown to be safe. It should be advisable to perform dedicated studies about vitamin D levels in COVID-19 patients with different degrees of disease severity(5).”

So, we don’t know yet if Vitamin D is going to be any help in the fight against COVID-19, but Vitamin D is a nutrient of concern, pandemic or not. You need to get about 15 minutes per day of full sun exposure on your arms to meet the recommendation for Vitamin D for most people, which doesn’t sound like much, but nowadays we work inside or live in climates where there is little sunlight during winter months or slather on sunscreen to block harmful UV rays. Few people get enough vitamin D from sun exposure, especially during winter months. There are not a lot of food sources of this important vitamin. It is found in fish, egg yolks, liver, fortified dairy products, and irradiated mushrooms, but it’s hard to eat enough of these foods to get adequate D. For example, one egg has less than 10% of what a typical healthy person needs in a day, and some people may need more.
Dietitians generally recommend getting vitamins and minerals through food rather than taking a supplement, but considering the above, supplementing may be necessary for some of us. If you can get a blood test to learn your Vitamin D levels, I would recommend finding out if you are okay, but the reality is, many people fall short of the mark. Here are few things to think about for yourself:

• The Recommended Dietary Allowance (RDA) for Vitamin D is 15 mcg / 600 IU per day for adults.
• Our bodies store Vitamin D, so if our blood levels get low, we can draw from storage. But if you find your serum D level is low, it means your body has already depleted its stores. Therefore, not only do you need to get the RDA, but you may need to take more to replete your stores.
• If you are trying to replete your vitamin D levels with sun exposure, you need to consider that too much sun can increase your risk for skin cancer.
• Certain medications may block the body’s ability to make Vitamin D from sunlight, which is another reason older adults tend to be low in D.

One of the recent studies I read about D and COVID-19 recommended people who are at risk get their vitamin D levels up by taking 10,000 IU (International Units) per day for a few weeks, and then going down to 5000 IU for a while. However, the tolerable upper level (TUL) for the vitamin is currently set at 4000 IU. Although doses up to 10,000 IU have not shown any negative effects, you don’t want to risk getting too much D! Its toxic effects are bad including calcification of organs. Dosing needs to be tested further to establish safe and practical guidelines. There are a couple additional points worth making:

• Don’t take high doses of calcium with high doses of D if you want to avoid the calcified organs.
• Some sources recommend supplementing Magnesium along with D.
• The supplement industry is not regulated – what’s on the label may not be what’s in the bottle.
• You won’t get Vit D toxicity from too much sun exposure, but UV rays can still be harmful.
• Fun Fact: Infants need a Vitamin D supplement because breast milk does not contain it.

So what does it all mean? Well, don’t get too excited about Vitamin D being the coronavirus hero, but it is something we should be addressing for our overall health anyway. If you choose to supplement, do some research rather than relying on labels when choosing a brand and a dosage. Personally, I had my blood tested a while ago, and my levels were a little low, so I get a bit of sun when I can and supplement above the RDA, but below the TUL. Done right, supplementing with Vitamin D won’t hurt us, and it might give us a leg up should we get exposed to COVID-19. Bummer that it took a terrible virus to get us to start paying more attention to Vitamin D.

Here are some resources I used, in case you are interested:

1. Ran L, Zhao W, Wang J, et al. Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials. Biomed Res Int. 2018;2018:1837634. Published 2018 Jul 5. doi:10.1155/2018/1837634
2. Grant WB, Lahore H, McDonnell SL, et al. Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):988. Published 2020 Apr 2. doi:10.3390/nu12040988
3. Han JE, Jones JL, Tangpricha V, et al. High Dose Vitamin D Administration in Ventilated Intensive Care Unit Patients: A Pilot Double Blind Randomized Controlled Trial. J Clin Transl Endocrinol. 2016;4:59‐65. doi:10.1016/j.jcte.2016.04.004
4. Alipio MM. Vitamin D supplementation could possibly improve clinical outcomes of patients infected with Coronavirus-2019 (COVID2019). This preprint research paper has not been peer reviewed. 2020 Apr 9. Electronic copy available at: https://ssrn.com/abstract=3571484.
5. Ilie PC, Stefanescu S, Smith L. The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality [published online ahead of print, 2020 May 6]. Aging Clin Exp Res. 2020;1‐4. doi:10.1007/s40520-020-01570-8
6. Ross AC, Taylor CL, Yaktine AL, et al., editors. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Washington (DC): National Academies Press (US); 2011.

My name is Lorelei Sturm. Some of you may know me as a yoga instructor with Chicago’s Neighborhood Fitness Centers. I am also a Registered Dietitian with a Master’s degree in Nutrition. CNF is committed to helping its members lead healthier lives by encouraging wellness and a healthy lifestyle in addition to fitness. Let me know if you have any nutrition questions in the comments below.
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