Newsletter #286: New Research on Supplements & Muscle 💪🏼
Hey y’all, this week I thought I would take a look at a couple of new studies examining how creatine and ergothioneine — both substances we have discussed before in previous newsletters — enhance exercise performance through their impact on skeletal muscle. Let’s take a look 👀
This Week’s Research Highlights
Creatine enhances repeated sprint performance by fighting fatigue at the most difficult point.
Many athletic endeavors, such as team sports and martial arts, demand the ability to perform repeated intense efforts with very brief recovery intervals. This type of exercise is fueled in part by phosphocreatine stored in skeletal muscle, which can help replenish ATP by donating a phosphate group. The problem is that during each sprint, muscle phosphocreatine drops by more than 50%, and it takes a little while to resynthesize — even after six whole minutes of rest, phosphocreatine levels might only be restored to 85% of the prior resting level. Clearly, finding a way to augment the rate of phosphocreatine synthesis could help sustain high-intensity effort and stave off fatigue through repeated sprint intervals with limited rest time.
To examine whether supplementation with creatine monohydrate might be useful to this end, UK researchers recruited 16 healthy male students involved in recreational sports at Loughborough University. Prior to exercise testing, the participants completed five practice sessions on a treadmill to familiarize themselves with the procedure. Then, all participants received placebo supplementation (glucose at a dose of 75 mg per kilogram, taken 4 times per day) for 5 days and performed a baseline repeated sprints test (6 rounds of 10 second sprints on a non-motorized treadmill).
At this point, the subjects were split into two matched groups, and were assigned to either continue to receive placebo, or creatine monohydrate (75 mg per kilogram, taken 4 times per day). This creatine regimen resulted in doses of around 20-24 grams, a very high "loading" dose devised to rapidly increase creatine content in the participants' muscles. On the sixth day of the supplementation period, all participants returned to the lab and repeated their six 10 second sprints.
The creatine group showed clear improvements in performance. After loading with creatine, their mean power output increased by 4.5%, and their mean running speed during the last 5 seconds of the sprints increased by 4.2-7.0%, during the last three sprints. So, the creatine wasn't enhancing peak power or peak speed, but helping maintain intensity during the last parts of the sprints, when they would normally be succumbing to fatigue.
This is obviously advantageous in the context of a competition, when you're pushing yourself to the max and don't have much time to recover. It would also be beneficial during training sessions, since it would enable athletes to increase their running distance by 4-5%, thus boosting the total training load with less metabolic cost.
Finally, this performance boost is particularly impressive because the body mass of the creatine group increased by around a kilogram on average, which would normally slow a runner down.
The antioxidant ergothioneine boosts aerobic performance without interfering with exercise adaptations.
Consuming primary antioxidants, like vitamin C, can help reduce inflammation and oxidative stress associated with exercise, which could be useful in the short term for managing soreness and fatigue. However, this strategy appears to be counterproductive over the long haul, because we now know that reactive oxygen species are a trigger for adaptations to exercise, like mitochondrial biogenesis and improved insulin sensitivity. That means that when you take large doses of vitamin C close to exercise, you may be blocking the signals your body needs to make the types of adjustments needed to get faster, stronger, boost stamina, etc. Moreover, primary antioxidants can block exercise-induced increases in antioxidant enzymes.
There is another class of antioxidants, known as secondary antioxidants, which work in a totally different way. This includes substances like polyphenols, which don't directly mop up free radicals, but instead activate a stress response at the cellular level, which boosts our natural defenses against reactive oxygen species. In other words, they fight oxidative stress in a way that more closely mirrors exercise, and could thus be characterized as exercise mimetics.
To examine whether these secondary antioxidants could provide the best of both worlds (reduce exercise-induced stress without interfering with adaptive signaling), researchers took 18 female mice and divided them into control and experimental groups. The experimental group was administered ergothioneine, an antioxidant compound that is found abundantly in mushrooms. At baseline, maximum aerobic speed was the same for both groups. After one week of supplementation, the mice performed a maximum time-to-exhaustion test by running on a treadmill at 70% of their individually calculated max aerobic speed.
The ergothioneine led to a substantial improvement in performance in these mice. Time to exhaustion was 41% longer in the ergothioneine group, compared to controls (71.55 ± 14 minutes versus 50.4 ± 8.41 minutes).
When the researchers took a closer look inside the leg muscles, they noticed that markers of exercise-induced oxidative damage were similar in both groups, even though the ergothioneine group had exercised harder and therefore should have exhibited greater free radical production.
Importantly, this antioxidant effect didn't adversely affect exercise adaptations. In fact, the contrary appeared to be the case. Primary antioxidants interfere with exercise adaptations in part by blocking activation of the PGC1α pathway. However, PGC1α protein levels were the same in both groups, and markers of mitochondrial content and capacity were not lower in the ergothioneine group.
Perhaps most interestingly, ergothioneine increased protein synthesis, and promoted activation of muscle satellite cells. Satellite cells are the primary stem cells in skeletal muscle, and muscle fibers depend upon them for growth and regeneration.
So, taken together, it looks like ergothioneine was helping facilitate muscle recovery and remodeling, but without the downsides associated with primary antioxidants.
Random Trivia & Weird News
🍍 Hawaiian pizza is not actually from Hawaii.
Sam Panopoulos, a restauranteur from Greece who immigrated to Canada when he was 20, created the first Hawaiian pizza at the Satellite Restaurant in Ontario in 1962.
It’s not even directly inspired by the Aloha State; Panopoulos chose the name based off of the brand of canned pineapple that was being used.
Initially, the unconventional toppings were not very well-received, and the combination remains polarizing to this day.
Podcasts We Loved This Week
- Shona Halson: Sleep, recovery, and fatigue in athletes. Via Inside Exercise.
- • Noah Whiteman: How poisons have shaped life on Earth. Via Science Friday.
Products We Like
California Olive Ranch Extra Virgin Olive Oil
You would think that picking out some extra virgin olive oil would be pretty simple, but apparently not. There have been some reports suggesting that a majority of “olive oil” that is commercially available may actually be diluted in unknown proportions with cheaper refined oils. For instance, researchers at UC Davis found that 69% of imported olive oil samples (including brands like Bertolli and Colavita) did not meet chemical or sensory standards set by the International Olive Council and the USDA, suggesting compromised quality. However, one brand that consistently passes the tests is California Olive Ranch. And fortunately, it’s pretty affordable and easy to find — you can get it via Amazon but I’ve also seen it at grocery stores, even Wal-mart.
humanOS Catalog Feature of the Week
The How-to Guide to the Mediterranean Diet
In this reference sheet, we go over the fundamental principles of the Mediterranean diet, what components of the diet make it healthy, and what sorts of foods and beverages you should consume in order to achieve the best possible version of this dietary pattern based on the current scientific literature. Great if you’re looking for a basic, efficient guide to how to Mediterraneanize your eating habits.
For a little bit of a deeper dive, you can refer to our Mediterranean Program, which delves into the background of the Mediterranean diet as well as the clinical research.