The running science nerd alert.
Learn to train smart, run fast, and be strong with Thomas Solomon PhD 
May 2024
The latest research studies on exercise science and sports nutrition are here.
You can use them to help level up your running performance or coaching practice.
The studies are divided into sub-topics:
training methods, sports nutrition and hydration, athlete health (inc. mental health), and female athlete physiology. Plus, there’s my beer of the month to wash it all down.
I’ve provided a brief conclusion from each study but click on the study title to go deep and read the full paper.
My favourite paper this month.
Randomised controlled trial: Sodium bicarbonate induces alkalosis, but improves high-intensity cycling performance only when participants expect a beneficial effect: a placebo and nocebo study. Zagatto et al. (2024) Eur J Appl Physiol.
“The present study showed that, although the sodium bicarbonate supplementation, independently of visual and verbal information provided (i.e., ergogenic, inert or harmful), provided the physiological environment to allow for an ergogenic efect (as evidenced by the alkalosis that it induced), this did not infuence cycling performance (i.e., time to task failure), or indicators of neuromuscular fatigue. Participants seemed to improve performance compared to the control condition, only when they were informed that they were ingesting an ergogenic, substance, as opposed to believing that they were receiving an inert, or ergoyltic substance. These data appear to indicate a potential placebo efect on sports performance, although further research is required to replicate and confrm this finding.”
Null findings.
Journals should never reject papers because the authors don’t find a beneficial effect of an intervention, no difference between groups, or no “statistical significance”. Doing so inappropriately removes null/negative findings from the evidence base, consequently creating a publication bias in favour of only positive effects becoming known. Unfortunately, I (and many of my colleagues) have had several papers rejected by journal editors because “your study doesn’t find a positive effect”. This is worrisome because null findings are important; I love it when journal editors agree with that sentiment! 
Observational study: Menstrual Cycle Phase has no Influence on Performance-Determining Variables in Endurance-Trained Athletes: The FENDURA Project. Taylor et al. (2024) Med Sci Sports Exerc. “The present study found no influence of menstrual cycle phase on the main determinants of endurance performance, such as V̇O2peak, %V̇O2peak at onset of bloodlactate accumulation, running economy and mean 30 second power output, in eumenorrheic endurance-trained women. Moreover, no significant associations were observed between the absolute concentrations of estrogen, progesterone, or estrogen to progesterone ratio measured in the various menstrual cycle phases. However, testosterone was positively associated with mean 30 second power output and peak 30 second power output. The early follicular phase–mid luteal phase changes in V̇O2peak were inconsistent between-individuals and across cycles and no phase-specific patterns for improved or reduced performance-determining variables were observed on a group level. Given these findings, researchers should avoid excluding female participants from studies investigating responses to similar performance-determining variables based on the idea that menstrual cycle phase will influence the outcomes on a group level.”Training methods.
Systematic review and meta-analysis: Effect of Strength Training Programs in Middle- and Long-Distance Runners' Economy at Different Running Speeds: A Systematic Review with Meta-analysis. Llanos-Lagos et al. (2024) Sports Med. “Strength training with high loads (greater than or equal to 80% of one repetition maximum) can improve running economy and might be particularly effective in athletes running at high speeds (e.g., faster than 12.00 km/h) and/or possessing a well-developed VO2max. Plyometric training could improve running economy at speeds less than 12.00 km/h. The combination of two or more strength training methods (e.g., high load training, plyometric training) may induce greater running economy improvement, compared to isolated training methods. These results are based on 31 studies with moderate to low certainty of evidence for the main outcomes, involving a total of 652 middle- and long-distance runners.” Systematic review and meta-analysis: The Effect of Strength Training Methods on Middle-Distance and Long-Distance Runners' Athletic Performance: A Systematic Review with Meta-analysis. Llanos-Lagos et al. (2024) Sports Med. “Strength training with high loads (greater than or equal to 80% of one repetition maximum) can improve time trial and time to exhaustion running performance. The combination in a program of two or more strength training methods (i.e., high loads, submaximal loads [40–79% of one repetition maximum], and/or plyometric training) may induce greater running performance improvement compared with one method alone. Maximal oxygen consumption, velocity at maximal oxygen consumption, maximum metabolic steady state, and sprint capacity exhibited trivial changes after strength training. The results are based on 38 studies and 894 (651 male individuals and 243 female individuals) middle-distance and long-distance runners, aged between 17 and 40 years, with a very low to moderate certainty of evidence.”Sports nutrition and hydration.
Randomised controlled trial: The impact of 48-h high carbohydrate diets with high and low FODMAP content on gastrointestinal status and symptoms in response to endurance exercise, and subsequent endurance performance. Scrivin et al. (2024) Appl Physiol Nutr Metab. “Exertional stress in isolation interferes with gastrointestinal integrity; however, consuming a high carbohydrate intake 48 h prior to exertional stress may lessen any significant changes to the intestinal epithelium. It appears that exertional stress also affects gastrointestinal function, specifically delaying orocecal transit time, rather than any dietary FODMAP (fermentable oligo-, di-, and mono-saccharide and polyol) load manipulation. The severity of exercise-associated gastrointestinal symptoms was greater pre- and during exercise in high carbohydrate high FODMAP trials; however, this did not impact feeding tolerance or exercise performance outcomes. Therefore, endurance athletes who experience exercise-associated gastrointestinal symptoms may benefit from consuming a high carbohydrate low FODMAP diet 48 h before exertional stress to mitigate any gastrointestinal integrity changes and reduce exercise-associated gastrointestinal symptoms severity before and during exercise.” Randomised controlled trial: Effects of a 10-Week Exercise and Nutritional Intervention with Variable Dietary Carbohydrates and Glycaemic Indices on Substrate Metabolism, Glycogen Storage, and Endurance Performance in Men. Moitzi et al. (2024) Sports Med Open. “While only the low carb high fat diet showed an improvement in fat oxidation and the high carb HIGH glycemic index group increased peak running speed and showed a trend towards an improvement in time to exhaustion, the high carb LOW glycemic index group appears to combine both effects on substrate metabolism and performance. Administered under free-living conditions, energy intake changed in high carb LOW glycemic index diet, possible due to higher intake of fibre, stable insulin levels and associated higher feeling of satiety. Energy intake in high carb HIGH glycemic index showed no changes and in low carb high fat a trend towards a reduced intake was observed. While changes in body weight and composition were more pronounced in high carb LOW glycemic index and low carb high fat group, muscle energy storage showed beneficial improvements in endurance runners on a HIGH glycaemic index diet. With the muscle glycogen content being significantly lower in low carb high fat compared to high carb LOW glycemic index group, it can be assumed that this might be a limiting factor in maximum values for the graded exercise test.”Athlete health (including mental health).
Randomised controlled trial: Gastrointestinal function following endurance exercise under different environmental temperatures. Sumi et al. (2024) Eur J Appl Physiol. “Endurance exercise in a cold environment failed to attenuate small intestinal damage and delayed gastric emptying rate, whereas exercise in a hot environment exacerbated small intestinal damage and delayed gastric emptying rate compared with same exercise in a thermoneutral environment. These fndings suggest that gastrointestinal function following endurance exercise was similar between the thermoneutral and cold environments, while endurance exercise in a hot environment reduced gastrointestinal function compared with same exercise in a thermoneutral environment.”The placebo effect.
Randomised controlled trial: Sodium bicarbonate induces alkalosis, but improves high-intensity cycling performance only when participants expect a beneficial effect: a placebo and nocebo study. Zagatto et al. (2024) Eur J Appl Physiol. “The present study showed that, although the sodium bicarbonate supplementation, independently of visual and verbal information provided (i.e., ergogenic, inert or harmful), provided the physiological environment to allow for an ergogenic efect (as evidenced by the alkalosis that it induced), this did not infuence cycling performance (i.e., time to task failure), or indicators of neuromuscular fatigue. Participants seemed to improve performance compared to the control condition, only when they were informed that they were ingesting an ergogenic, substance, as opposed to believing that they were receiving an inert, or ergoyltic substance. These data appear to indicate a potential placebo efect on sports performance, although further research is required to replicate and confrm this finding.”Female athlete physiology and sex differences.
Observational study: Menstrual Cycle Phase has no Influence on Performance-Determining Variables in Endurance-Trained Athletes: The FENDURA Project. Taylor et al. (2024) Med Sci Sports Exerc. “The present study found no influence of menstrual cycle phase on the main determinants of endurance performance, such as V̇O2peak, %V̇O2peak at onset of bloodlactate accumulation, running economy and mean 30 second power output, in eumenorrheic endurance-trained women. Moreover, no significant associations were observed between the absolute concentrations of estrogen, progesterone, or estrogen to progesterone ratio measured in the various menstrual cycle phases. However, testosterone was positively associated with mean 30 second power output and peak 30 second power output. The early follicular phase–mid luteal phase changes in V̇O2peak were inconsistent between-individuals and across cycles and no phase-specific patterns for improved or reduced performance-determining variables were observed on a group level. Given these findings, researchers should avoid excluding female participants from studies investigating responses to similar performance-determining variables based on the idea that menstrual cycle phase will influence the outcomes on a group level.” Observational study: Female Athlete Research Camp: A Unique Model for Conducting Research in High-Performance Female Athletes. McKay et al. (2024) Med Sci Sports Exerc. “In the naturally cycling athlete cohort, just one athlete reached criteria for classification as eumenorrheic, with five athletes showing evidence of menstrual cycle dysfunction. The prevalence of symptoms on any given day was similar between the naturally cycling athlete cohort (33.7%) and athletes using hormonal contraception (22.9%; P = 0.376); however, more symptoms were reported in the naturally cycling athlete cohort, suggesting that they were more likely to report multiple symptoms. Regardless of menstrual cycle function, there was a significant, positive association between bleeding and symptoms (P less than 0.001), where athletes were more likely to report one or more symptoms on bleeding (50.1%) compared with nonbleeding days (22.0%). Excellent resources outlining nomenclature and research methodologies for conducting sport and exercise sciences research with female participants have recently been published. However, further work is needed to address the range of special challenges of studying female athletes, particularly high-performance athletes in real-world situations. This article shares insights into our experiences and recommendations for conducting research in the daily training environment of female athletes. We provide information on the menstrual cycle characteristics of our cohort of highly trained First Nations female Rugby League players both to demonstrate the challenges of working in this area, as well as to provide a background to the series of individual data sets that were collected within the Female Athlete Research Camp research-embedded training camp.”
And, to help you wash down the latest evidence, here's a snifter from my recent indulgence...
Thomas Solomon’s beer of the month.
Layer Cake.
Brewdog (Ellon, Scotland).
Pastry stout.
7% ABV.
How would I describe this beer? 
“Hazelnut to the eye; mildly coffee and cake-like to the nose; roasted marshmallow foam on the tongue; smooth and biscuity down the hatch, with a soothing aftertaste of cake and pleasure. If Daniel Craig was a stout: Layer Cake.”
What is my Rating of Perceived beer Enjoyment? 
RP(be)E(r) = 8 out of 10.
Access to education is a right, not a privilege:
Equality in education, health, and sustainability is important to me. I was lucky to be born into a social welfare system where higher education was free. Sadly, that is no longer true, so I want to provide access to running performance and sports nutrition education to folks from all walks of life. This nerd alert newsletter is just part of that offering. You can find more free educational resources from me, Thomas Solomon PhD, at veohtu.com.
Every day is a school day.
Empower yourself to train smart.
Think critically. Be informed. Stay educated.
Disclaimer: I occasionally mention brands and products but it is important to know that I am not affiliated with, sponsored by, an ambassador for, or receiving advertisement royalties from any brands. I have conducted biomedical research for which I have received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, A.P. Møller Foundation, and Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on their research and innovation grant applications and I’ve provided research and science writing services for Examine — some of my articles contain links to information provided by Examine but I do not receive any royalties or bonuses from those links. These companies had no control over the research design, data analysis, or publication outcomes of my work. Any recommendations I make are, and always will be, based on my own views and opinions shaped by the evidence available. My recommendations have never and will never be influenced by affiliations, sponsorships, advertisement royalties, etc. The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.