Should we eat after exercising?

In this post, I hope to answer some questions that some of you may have (and I know I did have) when starting out strength training and working around the intricacies of how one’s nutrition works to maximize your hard work. Contrary to what social media may say, you don’t have to starve yourself in any way to lose weight or see results in the gym; rather (and though it may seem contradictory), ingesting proper nutrition is essential post-workout. Here’s why.

Recovery

Ideally, you should be giving your best in every session/workout and throughout this process, your muscles are put under pressure and working hard by releasing energy. Where does this energy come from? Certainly not just appears out of nowhere, but rather from glycogen stores - the main source of metabolic fuel for your body (1) - When needed, such glycogen stores in muscles are broken down into soluble glucose molecules by the process of glycogenolysis for muscle cells to release energy and contract. Consequently, the more stress you put your muscles under during exercise, the more glycogen stores that are depleted. In other words, your body uses up glucose in the bloodstream for energy release, especially increasing in rate during exercise, which decreases your blood glucose concentration, so your muscles also work extra hard to deplete the glycogen stores to increase your blood glucose concentration back to its optimum range.

Essentially, after exercise, your glycogen stores are low, and you need to replenish such stores to not only energize yourself again but to fuel your body for recovery, in anticipation for the next training session. How do we do so? By looking at our main sources of glycogen, which come from carbohydrates. Now, the majority of foods all contain carbs, but after looking further, I found that it’s the type of carbs we eat that helps us replenish stores sufficiently.

Low vs High GI Carbohydrates

I’m sure some of you have already heard of the term GI, or, glycemic index, from social media these days, but essentially it’s how quickly such foods are digested and absorbed into your bloodstream. Meaning, a higher GI food will enter the bloodstream quicker and made available for use by cells. It becomes elusive when determining whether one should eat higher or lower GI carbs post-exercise, since higher GI carbs tend to cause higher glucose spikes (yet again, another demonized term by the fitness community). However, in one study that I found (2) which linked the effects of low or high GI carbs with sleep quality, another huge factor for recovery. The study showed the participants that ate higher GI carbs had overall better sleep efficiency and sleep time, indicating a positive indirect role high GI carbs played in improving one’s future recovery and training. Better sleep = better recovery, concentration & reaction time = better, more consistent future performances.

For those who are unclear of what constitutes as high or low GI: Any carbs with an index lower than 55 is considered low (3), some examples would be wholegrain products, steel cut oats, white/brown rice, sweet potatoes etc. On the other hand, any carbs with an index higher than 70 is considered high, and some examples would be jasmine rice, white bread, potatoes etc. (If you don’t mind, eating the skin of starchy veggies like potatoes and sweet potatoes will lower the GI given the skin is high in fiber. I recently started doing this too because I also find that this adds a bit of extra texture, just make sure you rinse the outside well!)

Caution: Reality is, most processed/refined carbs are high in GI index, but this does not mean that you should exploit such an opportunity and gorge down 3 cheeseburgers, 2 pizzas and a chocolate milkshake right after your training to “recover”! In this case, you will truly exceed in calories and, over time, put on some weight and accumulate more body fat than muscles. It may seem counterproductive that after a long and hard session, we should be eating, because it would seem to waste all those calories that we’ve burned in the session, right? No, in fact, after looking into the importance of carbs for recovery and sleep, it’s extra important that you replenish your glycogen stores. Losing weight and becoming strong is a long process, as I’ve learned, so everything you do should facilitate the process in the healthiest way possible without starving yourself.

Summary: Try to consume some form of carbohydrate high in GI index to help replenish your glycogen stores to facilitate better sleep and recovery, in preparation to work for your next session!

Anything else other than carbs?

Other than your muscles depleting glycogen stores to release energy, the actual process of muscle contractions for movement strains your muscles, a lot. What does “straining” actually entail? When we exercise, our muscle microfibers become torn and damaged as a result of repeated contractions (both eccentric & concentric), which triggers a process where satellite cells fuse together and to the muscles fibers, often leading to increases in muscle fiber cross-sectional area, aka hypertrophy (4). Protein, as it turns out, is the macronutrient needed to facilitate the process of protein synthesis, hence the consumption of it after exercising becomes crucial to help muscle repairment. With this being said, I have noticed some influencers arguing that consumption of protein is not required immediately after a workout if the total daily protein intake is sufficient. However, from the numerous articles (5, 6, 7) that I looked over, it has been concluded that consuming ~20g of protein immediately post-workout helps kick-start protein synthesis and prevent protein breakdown as your body is fastest at absorbing molecules at that 20-30 minute window.

How does 20g of protein look like: The simplest and arguably “best” type of protein to consume post-workout is whey protein, which is fast-digesting and with each scoop of protein powder (of your choice) or a bottle of protein shake contains ~20g, so drinking one of these shakes would be a good option. Otherwise, 20g of protein may come in the form of 90g of chicken breast (like a fist-size), 100g of salmon/ground beef, or 200g of tofu.

Should we eat differently for cardio workouts vs. weight training?

When I first came across this question, my first intuitive thoughts were directed towards the varied demands during cardio compared to weight training. Your glycogen stores would be expended at a quicker rate during long aerobic exercises running/cycling/swimming; Contrastingly, during weight training you’re intentionally eccentrically contracting your muscles to focus on a deep stretch, purposefully tearing those microfibers. And my hypothesis proved correct, since according to this article, one should indeed focus on eating more carbs during and after cardio workouts while one should focus on protein after weight training to maximize protein synthesis.

What do I eat?

For me, it’s become a habit of mine to do ~30 minutes of fasted cardio - mainly incline walking - before having breakfast. At first, I did feel hungrier and more tired after doing cardio but after committing to it for a few weeks, your body adapt and now the cardio works to energize me for the day. After each fasted cardio session, my breakfast looks something like this: Non-fat Greek yogurt (Chobani/Fage being the superior choices) with protein granola and sometimes some blueberries for added sweetness and texture. Nowadays, I also enjoy searing some lean ham slices and whipping up an egg white omelette to go with it. Absolutely delicious and come to less than 250 kcal (30g protein & 13g carbs) if you’re into counting macros.

After weight training or heavy cardio like badminton training, I like to have a meal to not only refuel my body, but allow myself to have a cooldown period to not feel exhausted for the rest of the day. There is absolutely no need to starve yourself after a session to feel to “not let your hard work go to waste”. This is a mindset I used to have, but that only led to a bigger appetite when it came to mealtime and I would eat more just because I’d starved myself beforehand. With that being said, my post-training meals always focus on a lean protein source and I understand that not everyone can get behind the idea of eating chicken breast every day, so you don’t have to. For me, it’s normally ~200g chicken breast (raw weight) with a complex carb with relatively high GI, my favorites being ~150g of steamed potatoes/sweet potatoes. Fiber is also crucial for me to keep me satiated, so I’ll normally just blanch some leafy greens and drizzle a bit of soy sauce with it. Again, not everyone has to be as obsessive over clean as I do because what’s most important is developing healthy eating habits and having consistency (I just happen to enjoy it). An especially compelling analogy I came across is like finding a few colored M&Ms in a cup of dark coffee beans, the few salads that you eat every 3 months won’t even make a dent in your McDonald’s diet.

Conclusion

This is my first deep dive on nutrition and actually looking into sports-related research articles to see what research says about the interdependence of nutrition with post-workout recovery. Although these were things I’ve already heard about through social media, it was interesting to see the importance of high GI carbs on the effects of sleep. It’s actually got me slightly worried because sometimes I struggle with quality sleep and now it’s really up to me to adjust accordingly to hopefully maximize my recovery and muscle growth. Also, who knew that one only really needs ~20g of carbs and protein post-workout (obviously adjusting accordingly) but as a guideline, this was a good benchmark to know.

These types of posts definitely takes longer to write but certainly very insightful and like I said, I love understanding more about the food we eat and how we can benefit from them, not fear them.

Thanks for reading, and see you all in a bit.

-Winnie 26/08/2024