Peak & Mean Power + Power Capacity Increase (5-8%) in 11 Trained Women W/ OTC Rhodiola Extract in Non-Sponsored Cross-Over Trial ++ Review of Evidence from Other Studies
Some of you will probably remember that “Rhodiola” aka”Golden Root” is a putative adaptogen, i.e. a “nontoxic [sic!] substance and especially a plant extract that is held to increase the body’s ability to resist the damaging effects of stress and promote or restore normal physiological functioning” (Merriam-Webster Medical Dictionary)…
No? Well, I remembered “Rhodiola Rosea”, as I should have written before to avoid confusion with other plants from the same genus, when I saw a recent post by Jason Cholewa on Facebook.
The link to a study that was attached to the post didn’t just remind me of this almost forgotten herb (ten years ago it was used in many more ‘kitchen-sink supplements’ than today); It drew my attention to a recent paper by scientists from the Samford University in Birmingham, USA (Ballmann 2018).
In the conclusion of their abstract, the scientists, …, write about the standardized Golden Root Extract (#GRE) that they tested in N=11 physically active college-aged females (=accruing at least 150 minutes/week of moderate physical activity) in a within groups counterbalanced placebo-controlled trial that…
“GRE [more specifically, 3x500mg of a std. Rhodiola extract per day for three days and 500mg in the AM on the test day,] may possess ergogenic benefits and findings hold important implications for boosting anaerobic performance in repeated anaerobic bouts of exercise” (
Needless to say that this sounds interesting for all sorts of sports and athletes ranging from sprinters over team sports athletes to the average gymrat. And, if we take the large effect sizes into account, I would speculate that your next question is:
“Where can I buy this stuff?”
The supplement was administered thrice a day for three days (3x500mg/g) and once 30 minutes before the warm-up/testing procedures (1x 500mg/d). Each 15-second all-out-pedaling bouts during the Wingate test was followed by a 2 minute active recovery rest period, in which subjects pedaled at their own pace against an unloaded pedal resistance.
The good news is: While it is a special product that is standardized for 3% total rosavins and 1% salidroside, you can, much in contrast to a dozen other promising herbal supplements, buy it (almost) everywhere – even the exact product that was used in the study at hand, i.e. NOW Food‘s 500mg caps which go by the simple name “Rhodiola”.
This makes the study at hand particularly interesting for you, me, and everyone else who’s always on the look-out for safe and still functional performance boosters that are actually available on the market (vs. some exotic extracts you would have to order from a research supplier such as Sigma Aldrich).
In that, it is not clear if a ‘loading phase’ as the scientists used it in the study at hand is even necessary. Other studies, I am about to cite later in this article seem to suggest that an effect can be seen immediately (~1h) post ingestion and evidence of a cumulative effect is – as of now – not available and warrants further research (see red box on potential anti-hormetic effects, too).
“So, I’ll take 500 mg 30-60 minutes before workouts, right? Won’t more help more?
If this is not your first visit at suppversity.com, you should know by now that “more helps more” is as invalid for supplements and exercise performance as it has been shown to before money and happinesss (Easterlin 1973).
|Figure 1: In Noreen’s 2013 study, the provision of R. rosea at a dosage of 3mg/kg only once, 1 hour before the 6k-cycling trial, yielded significantly improved time-trial times (left) and reduced rates of perceived exertion (RPE | p = 0.04), as well as RPE/power (right | p = 0.007) compared to a carbohydrate placebo (adapted from Noreen 2013).|
Moreover, studies like Noreen et al. (2013 | see Figure 1) or Duncan & Clarke (2014) seem to suggest that an even lower dosage of 3mg/kg of the same standardized extract taken 1h before (in those studies albeit aerobic) exercise tests will have significant ergogenic effects, too.
Overall, it has to be said, though that the optimal dosing strategy is still in the open, though, because: (a) we do not have any studies comparing different dosing regimens directly, and (b) we do not even know how Rhodiola Rosea does whatever it is, it does. If we knew (b), we could at least speculate about the optimal timing and potential dosing thresholds, but as of yet, there are only various unconfirmed and often disputed hypotheses as to how Rhodiola works.
|Figure 2: When it comes to choosing whether and at which dose to use of ROS scavengers you must consider hormetic dose-response relationship between stress exposure (X-axis) and adaptational response (Y-axis). Stimulatory effects occur in the low-dose region at the left of the no-observed-effects-level (NOAEL), whereas adverse effects occur in the high-dose region at the right of the NOAEL – first published in July 2018|
A long(er)-term (=4 week) study, in which the Polish Rowing Team received 100 mg of a non-specified “R. rosea concentrate”, found increases in total plasma antioxidant capacity and a reduced superoxide dismutase activity in erythrocytes directly after and 24 hr after an exhaustive bout of exercise was also observed in rowers by Skarpanska-Stejnborn et al (2009) – both effects that are relatively unlikely to translate to a reduction in the adaptive response to exercise. Due to the fact that we’re talking about highly trained athletes, it is also not that surprising that the already marginal (and everything but statistically significant) increases in performance markers the scientists observed over time showed no inter-group differences.
Needless to say that “additional research is necessary” (I know I hate this sentence, too 😉 to finally answer your question, but as previously pointed out, I consider it unlikely that the regular use of Rhodiola, in a similar fashion as caffeine, would have negative effects on your gains.
These hypotheses include, most prominently, the ‘ATP hypotheses’. Unfortunately, researchers from the Air Force Research Laboratory (Walker 2007) found in their 2007 study that the significant increases in ATP-turnover/resynthesis that had been observed in a previous rodent study (Abidov 2003) doesn’t seem to occur in humans.
Walker et al. (2007) had used the same dosing scheme as Ballmann, but relied on what I would call a pretty odd performance test: wrist curls. Be that as it may,… their measurement of the ATP kinetics by phosphorus 31 nuclear magnetic resonance spectroscopy, revealed absolutely zero effects of the rhodiola supplement – whether that’s simply due to the hardly exhaustive nature of the exercise protocol in this Air Force study, is not clear, but I certainly wouldn’t discard the possibility of muscle-physiological/-metabolic effects completely with high(er) intensity exercise, yet.
The actual mechanism is not clear, but it could be of metabolic, muscle-physiologic or neuro-physiologic origin… or, obviously, a combination of all three!
If we look for other potential mechanisms, the previously cited study by Noreen et al (2013) comes to mind. The scientists Gettysburg College found significant performance improvements, in this case, improved 6-km cycle times (Figure 1, left), they ascribe to a reduced perception of effort (Figure 1, right). Similar beneficial effects on RPE were observed by Duncan & Clarke (2014), who tested the effects of 3mg/kg BW in ten young men, who completed two 30-minute cycling trials at an intensity of 70% of VO2Max in a double-blind, crossover design trial. Together these two studies seem to suggest that – at least during endurance exercise – the mechanism of action could, in fact, be of central neurological vs. peripheral muscle-physiological nature.
|Figure 3: Mean anaerobic performance variables over all three WAnTs (for individual data see Figure 4). Data are presented as mean ±SD. * indicates significantly different from placebo (p < 0.05 | Ballmann 2018)|
Since tests that would be able to confirm this hypothesis were not conducted in the Ballmann study, and the mean fatigue index (Figure 3, bottom right) was non-significantly elevated, not decreased, it does yet seem very unlikely that this is what triggered the beneficial effects Rhodiola had in this most recent study on the effects of Rhodiola on anaerobic exercise performance.
|Speaking of adaptogens: Ashwaghanda may be for gymrats, too | Human study showed significant body composition improvements in 2015.|
Could hormonal changes explain the benefits? You may remember the 2016 installment of the #ShortNews, in which I addressed a study showing significant increases in testosterone levels in response to 7x higher doses of a non-standardized Rhodiola product in exercise-trained mice (learn more).
Rhodiola is also said to have cortisol-lowering effects – a claim that corresponding product write-ups try to prove by citing studies like Jurcău et al. (2012), or Ross et al. (2014), which did, however, not investigate the cortisol response to exercise but other forms of stressors.
Studies that investigated the effects in conjunction w/ physical exercise found inconclusive effects w/ one study that used a combination of Rhodiola + carnitine showing a significant time, but no treatment effect (Muñiz-Pumares 2011). The same goes for the previously cited study by Noreen et al (2013), as well as a dose-escalation study in rodents that found no effect on either testosterone or cortisol of exercised mice on dosages of up to 300mg/kg (that’s already the human equivalent) of a mixed Rhodiola, Astragalus and Radix Paeoniae Alba extract (Chen 2017).
|Figure 4: Results from the study under review (Ballmann 2018) – Anaerobic performance outcomes compared from 1st, 2nd, and 3rd 15-second Wingate Anaerobic Tests (WAnT); Data are presented at mean ±SD; * indicates significantly different from 1st WAnT, # indicates significantly different from 2nd WAnT (p < 0.05).|
As far as the observed effects are concerned, it is worth mentioning that we’re talking about a cumulative effect, which occurred in the absence of significant effects in the individual 15s-bouts of all-out cycling (see Figure 4).
This is in line with the previously hinted at observation that there are more ‘Rhodiola studies’ using aerobic vs anaerobic outcomes to gauge its efficacy; and, more importantly, that the former are also more likely to report performance increases than studies that used (ultra-)short bouts of high-intensity exercises, such as the 3x15s Wingate tests.
Even if Rhodiola was more of an endurance supplement, though, this would not change the results of the study at hand: There’s a statistically significant cumulative effect over “only” 3x15s high-intensity cycling bouts in the study under review, which thus provides convincing evidence that: Athletes competing in sports that require intermittent all-out sprinting or other forms of intermittent high-intensity exercise may benefit from standardized Rhodiola extracts.
In that, it is still not clear, whether the benefits, which I have summarized and plotted once more for you in Figure 5 (figure shows relative differences between Rhodiola and placebo), would occur with the 3mg/kg (for the ladies in the study at hand that would be ~200mg) dosage of the standardized extract that both, Duncan & Clarke (2014) and Noreen et al (2013), administered only once ~1h before the performance tests would be identical. How safe is rhodiola? While Rhodiola Rosea is not just easily available, but also classified as generally recognized as safe (GRAS), it should be mentioned that studies on potential supplement-drug interactions are ambiguous. While there’s evidence of competition for CYP2C9 (Thu 2016 & Thu 2017) and other CYP enzymes, and hence potential interactions with NSAIDs, certain diabetes meds, angiotensin II inhibitors (blood pressure), SERMs (tamoxifen) and even sildenafil, Noeldner et al. and Panossian et al. write that the IC50 for interactions with drug metabolizing enzymes is too high to be physiologically relevant for the proprietary dry extracts WS® 1375 and SHR-5, respectively… if you take any meds, though, it makes perfect sense to check with your doctor before you trial any Rhodiola supplement. Source