Jennifer Hanes MS, RDN, LD
Nutrition and exercise can be confusing all on their own. However, when combined, we have a whole new arena for people to add to the noise.
By now, we’ve all heard of carbo-loading for cardio and eating an enormous amount of protein to build muscle. But do these methods actually work? Should I eat a snack with protein or force down a disgusting protein shake from the health food store?
How does fats and fiber impact exercise?
Is it better to exercise on an empty stomach or right after eating?
Luckily, there have been many studies done to guide us.
Mainstream recommendations are to eat a light snack that includes carbs and protein about 1 hour before a workout to fuel you through your exercise.
The post-exercise window is treated with much more urgency.
We are instructed to consume a large amount of protein to begin protein synthesis (jump start muscle recovery) and carbohydrates to replete the glycogen stores in our muscles and liver and maintain a healthy blood glucose level and we have to be certain to eat this meal within 20 minutes of the conclusion of our workout.
A literature review performed in 2015 agrees that we should have a snack consisting of protein and carbohydrates before exercise, particularly if we exercise before breakfast.
In this study, we learn that a pre-workout snack immediately before exercise can do double duty as a post-workout meal. This is because you are still digesting the protein after your workout.
Results indicate a 130% increase in blood serum amino acids that continued to stay elevated for 2 hours after a workout.
Another study showed that 20 grams of whey protein taken immediately prior to resistance training elevated muscle uptake of protein by more than 4 times normal amounts and the effect lasted for 4 hours after the workout ended.
However, if it has been more than 3-4 hours since you last ate, the typical recommendation of 25 g of protein immediately after exercise seems warranted, particularly if muscle growth is your goal.
There has been a small body of evidence that shows that older adults need even more protein than younger trainers as their muscles do not uptake and utilize amino acids from proteins as well, though this field of study is relatively young and unexplored.
Exercise goals also dictate our nutrition needs.
Someone who is trying to gain muscle will need more protein than someone who is working to maintain their current physique.
Similarly, someone who is trying to lose a large amount of body fat should also increase their protein. Just not as much as a body builder would.
This is why it is recommended that you seek the help of a dietitian. We are trained and qualified to give nuanced and individualized advice.
My recommendation, based on this research, is to do what makes your stomach the most settled. I can’t eat right after a workout, so have utilized chocolate milk and various protein shakes for my post-workout recovery meal.
On the occasion that it’s been too long since I’ve eaten, and not wanting a full stomach during a workout, I’ve had a protein shake immediately prior to working out, and have always felt best going this route. Find what works for you and try to stick with it.
Carbohydrate loading is a concept used by endurance athletes.
When we perform an activity for long, sustained periods of time, we can deplete the carbohydrate stores in our liver and muscles.
Eating a carbohydrate-heavy meal before a workout can help fend off a blood sugar drop and allow us to work for longer.
Studies have shown that carbohydrate loading does fend off a drop in glycogen stores, but have not shown any improvement in performance as a result.
One study compared high fat vs high carbohydrate meals prior to endurance exercise and showed no difference in performance between the two exercisers. Additionally, a small study showed some improvement in performance when beetroot juice and caffeine are ingested before exercise.
In endurance activities, such as marathons, it becomes necessary to consume carbohydrates during exercise as well, as we will utilize our glycogen (carbohydrate) stores during the activity.
People accomplish this in different ways, depending on what their gut can handle and what improves their own performance. Carbohydrate and electrolyte gels are available. Sports drinks are a good option as well. Some people like bananas because they are easy to eat while moving, but others find this upsets their stomach.
If you are building up to longer exercise periods, experiment to see what works best for you.
Fats have not really been mentioned much, as they don’t play a huge role in muscle recovery or blood glucose levels. We should include fat in our diet to maintain our weight, carry fat-soluble vitamins, and provide essential fatty acids, but their timing is not important.
It is important to note that meals eaten prior to exercise should be low in fiber to avoid stomach upset during exercise.
Water should be consumed before, during, and after exercise to maintain fluid balance. When exercising at a high intensity, for over an hour, the use of an electrolyte and glucose balancing sports drink are important to prevent dehydration and dangerously low blood sodium level.
Before a workout, avoid high fat protein foods (such as hamburgers and sausage) high fiber energy bars, broccoli, Brussels sprouts, and onions as they may cause stomach upset during exercise.
Some people find that fructose upsets their stomach during a workout as well.
If this is the case, avoid fruit as well as sports drinks that contain high-fructose corn syrup, before and during exercise.
An apple and yogurt
Low fiber cereal with milk
Hard boiled eggs with toast
Sliced tempeh on half a bagel.
For information on how much protein is in common vegetarian foods, visit How Much Protein is in That?
Pecans make a yummy, quick snack!
Jennifer Hanes MS, RDN, LD is a registered dietitian, mom, wife, and vegetarian in North Texas. She has dedicated Dietitian Jenn to be a source of information, ideas, and inspiration for people like her, vegetarians that live with people with different dietary beliefs and/or needs in a multivore household.