The running science nerd alert.
Learn to train smart, run fast, and be strong with Thomas Solomon PhD 
July 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:
sports nutrition and hydration,
recovery (inc. sleep),
athlete health (inc. mental health),
injuries and rehab,
the placebo effect, and
female athlete physiology,
plus my beer of the month to wash it all down.
I’ve provided a brief conclusion from each study. However, you can click on the study title to go deep and read the full paper.
My favourite paper this month.
Randomised controlled trial: Personal belief on elastic tape and tape tension affect perceived performance, but not muscle activity and endurance. Lam et al. (2024) Physiother Theory Pract. (click the title to access the full article)
This study investigated the effect of faciliatory kinesiology tape on wrist muscle endurance performance, muscle activity, and self-perceived performance between people with different personal belief on kinesiology tape. In contrast with our original hypothesis, we found that facilitatory kinesiology tape, regardless of tape tension, did not improve muscle endurance performance and change muscle activity, regardless of participants’ personal belief on kinesiology tape. However, participants with positive belief perceived a better performance with a greater tension of kinesiology tape, while the perceived performance of participants with negative belief was not affected by kinesiology tapetension.
Sports nutrition and hydration.
Position stand: International society of sports nutrition position stand: ketogenic diets. Lea et al. (2024) J Int Soc Sports Nutr. (click the title to access the full article) Position of the International Society of Sports Nutrition (ISSN): 1. A ketogenic diet induces a state of nutritional ketosis, which is generally defined as serum ketone levels above 0.5 mM. While many factors can impact what amount of daily carbohydrate intake will result in these levels, a broad guideline is a daily dietary carbohydrate intake of less than 50 grams per day.
2. Nutritional ketosis achieved through carbohydrate restriction and a high dietary fat intake is not intrinsically harmful and should not be confused with ketoacidosis, a life-threatening condition most commonly seen in clinical populations and metabolic dysregulation.
3. A ketogenic diet has largely neutral or detrimental effects on athletic performance compared to a diet higher in carbohydrates and lower in fat, despite achieving significantly elevated levels of fat oxidation during exercise (~1.5 g/min).
4. The endurance effects of a ketogenic diet may be influenced by both training status and duration of the dietary intervention, but further research is necessary to elucidate these possibilities. All studies involving elite athletes showed a performance decrement from a ketogenic diet, all lasting six weeks or less. Of the two studies lasting more than six weeks, only one reported a statistically significant benefit of a ketogenic diet.
5. A ketogenic diet tends to have similar effects on maximal strength or strength gains from a resistance training program compared to a diet higher in carbohydrates. However, a minority of studies show superior effects of non-ketogenic comparators.
6. When compared to a diet higher in carbohydrates and lower in fat, a ketogenic diet may cause greater losses in body weight, fat mass, and fat-free mass, but may also heighten losses of lean tissue. However, this is likely due to differences in calorie and protein intake, as well as shifts in fluid balance.
7. There is insufficient evidence to determine if a ketogenic diet affects males and females differently. However, there is a strong mechanistic basis for sex differences to exist in response to a ketogenic diet.
Scoping study: Carbohydrate beliefs and practices of ultra-endurance runners in Ireland for gastrointestinal symptom management. Ryan et al. (2024) Front Nutr. (click the title to access the full article) Over half of the participants of this study had previously experienced gastrointestinal symptoms at similar frequencies, regardless of whether during training or events. Sourcing nutrition information from qualified personnel was rarely employed by the participants. Comparably, most based their practices on previous experimentation and experiences. Both dietary and non-dietary strategies to manage gastrointestinal symptoms were scarce. Supplementing with nitrates or probiotics were the most frequently reported dietary strategies, while other and portion control were their non-dietary counterparts. Comparing these findings to previous research, recruiting the same cohort is a challenge due to the sparsity of such investigations. However, these findings are similar to those recruiting endurance athletes and further highlight the vast range of gastrointestinal symptoms such populations experience. In order to develop adequate dietary and non-dietary recommendations to support ultra-endurance athletes’ physiological adaptations while simultaneously alleviating gastrointestinal symptoms, it is crucial that the relevant professionals have an in-depth understanding of these gastrointestinal symptoms and the mechanisms behind them. As well as this, further research should investigate how best to communicate and disseminate such information to the ultra-endurance running community to support their implementation of evidence-based practices. This, in turn, will work to reduce individuals’ risks of developing long-term, chronic health complications resulting from poor gastrointestinal symptom management and inadequate nutrition intake.
Recovery (including sleep).
Observational study: Ultramarathon runners and support crew: The influence of pre-race sleep and training profiles on performance in a 217-km mountain race. Daniel et al. (2024) Sleep Med. (click the title to access the full article) Athletes and support crew showed a morning type chronotype and a poor sleep quality, although with good sleep efficiency. Athletes who finished the race presented a higher sleep latency in training period. Sleep quality indirectly influences ultramarathon performance since athletes with higher sleep quality trained once more per week than athletes with poorer sleep quality, and a higher training frequency was correlated with a faster race time.
Athlete health (including mental health).
Randomised controlled trial: Low energy availability increases immune cell formation of reactive oxygen species and impairs exercise performance in female endurance athletes. Jeppesen et al. (2024) Redox Biol. (click the title to access the full article) The most important findings of the present study were that 14 days of low energy availability: (i) increased the capacity of peripheral blood mononucleocytes (PBMCs) to produce reactive oxygen species (ROS) as evidenced by an increased level of NADPH oxidase, and an amplified ROS production in PBMCs in response to acute exercise despite lower total work performed during the exercise test, as indicated by impaired exercise performance,
(ii) increased resting cortisol and altered the plasma inflammatory proteome at rest and following acute exercise, and
(iii) reduced the exercise induced mobilization of leukocytes. Moreover, three days of refueling led to restoration of cortisol levels and inflammatory proteins to initial pre-low energy availability levels, whereas it did not restore the low energy availability induced impairment in performance (20- min time trial).
Our study illustrates a substantial impact of short-term low energy availability on the immune system, as evidenced by altered redox balance in PBMC, altered immune/inflammatory proteome and a reduced exercise-induced mobilization of PBMCs. This finding suggests that low energy availability may heighten the susceptibility to infections and disease. Additionally, our study shows that, at a functional level, low energy availability reduces endurance exercise performance, an effect which was not reversible with three days of refueling. Taken together, these findings underscore the critical importance of limiting low energy availability exposure for female athletes.
Injury and rehab.
Consensus statement: 50 Years of Research on the Psychology of Sport Injury: A Consensus Statement. Tranaeus et al. (2024) Sports Med. (click the title to access the full article) Regarding injury risk, form strong relationships with your athletes and colleagues, screen athletes frequently for psychosocial stress and perceived recovery and consider stakeholder education around organisational injury risk factors. Regarding rehabilitation, incorporate elements of mindfulness and acceptance-based practices and cognitive-behavioural based programs to improve coping and provide time and space to contribute as much social support as possible. Regarding return to sport, utilise strategies that facilitate athletes’ sense of competence, autonomy, relatedness and facilitate clear lines of communication between athletes, coaches and medical staff.
Randomised controlled trial: Hip and core exercise programme prevents running-related overuse injuries in adult novice recreational runners: a three-arm randomised controlled trial (Run RCT). Leppänen et al. (2024) Br J Sports Med. (click the title to access the full article) What is already known on this topic? → A low number of studies have investigated exercise-based injury prevention in novice recreational runners, and the evidence is still very limited. What does this study add? → Physiotherapist guided hip and core focused exercise programme can help prevent lower extremity injuries in adult novice recreational runners. Hip and core focused training is especially effective to prevent lower extremity overuse injuries, which are common among novice runners. The ankle and foot focused exercise programme was not effective in reducing lower extremity injuries and was associated with an increased incidence of acute lower extremity injuries when compared to static stretching. How does this study affect research, practice or policy? → Prevention of running-related injuries is possible through hip and core focused training. This lowcost training can be done with limited equipment and is recommended for adult novice recreational runners. This study tested the programme efficacy in ideal conditions under physiotherapist guidance. The patient-driven effectiveness of the programme should be tested in the future.
The placebo effect.
Randomised controlled trial: Personal belief on elastic tape and tape tension affect perceived performance, but not muscle activity and endurance. Lam et al. (2024) Physiother Theory Pract. (click the title to access the full article) This study investigated the effect of faciliatory kinesiology tape on wrist muscle endurance performance, muscle activity, and self-perceived performance between people with different personal belief on kinesiology tape. In contrast with our original hypothesis, we found that facilitatory kinesiology tape, regardless of tape tension, did not improve muscle endurance performance and change muscle activity, regardless of participants’ personal belief on kinesiology tape. However, participants with positive belief perceived a better performance with a greater tension of kinesiology tape, while the perceived performance of participants with negative belief was not affected by kinesiology tapetension.
Female athlete physiology and sex differences.
Narrative review: The Menstrual Health Manager (MHM): A Resource to Reduce Discrepancies Between Science and Practice in Sport and Exercise. Claire Badenhorst (2024) Sports Med. (click the title to access the full article) Inadequate research, low menstrual health literacy, and lack of educational resources and training are barriers that prevent effective menstrual health monitoring for females, for both active individuals and elite athletes. The development of educational resources that use correct terminology (in lay language) is required for athletes, coaches and support staff. This strategy could help improve appropriate and effective menstrual cycle health monitoring for females in sport and exercise environments. A decision tree has been constructed for coaches, sporting organizations and athletes to inform decision-making on what menstrual health monitoring methods could be used, while also ensuring that there is some understanding/learning of what information will be provided.
Figure 1:
A basic decision tree for determining menstrual cycle status. Commencing at the black root node ‘female’, simple binary questions (orange) can be completed to move progressively until a leaf (blue) node is reached. If responses to binary questions land on the green leaf node, then the individual using the resource should progress to Fig. 4. IUD = intrauterine device.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
×
![]()
Figure 2:
An extension of Fig. 1 that can be used to determine the menstrual cycle status of a naturally menstruating female (black root node). Answering the menstrual cycle monitoring binary questions (orange) will progressively move the individual towards a leaf (blue), helping to establish the menstrual cycle status of the individual in each cycle. Detailed descriptions of each leaf (blue) are provided in Table 1. The menstrual cycle monitoring techniques and questions (orange) that are required to complete this decision tree are outlined in Table 2. Of note, ovulation in the decision tree has been stated as probable if a urinary ovulation test (LH surge) has been completed and is positive. To confirm ovulation a progesterone (P4) blood test will need to be completed 7–9 days after the urinary ovulation test. LH = luteinizing hormone.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
×
![]()
Figure 3:
Basic decision tree for hormonal contraceptive users. Commencing at a root node (black), binary questions (orange) can be completed until a leaf node is reached (blue). Details of each leaf node are provided in Table 3 and can be used collectively to provide education on the different types of hormonal contraception available to females. Details on menstrual health monitoring techniques for hormonal contraceptive users are provided in Table 2. OCP = oral contraceptive pill, IUD = intrauterine device.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
Image Copyright © the author, Claire Badenhorst (Sports Medicine). The article is licensed under a Creative Commons Attribution 4.0 International License.
×
![]()
Randomised controlled trial: Low energy availability increases immune cell formation of reactive oxygen species and impairs exercise performance in female endurance athletes. Jeppesen et al. (2024) Redox Biol. (click the title to access the full article) The most important findings of the present study were that 14 days of low energy availability: (i) increased the capacity of peripheral blood mononucleocytes (PBMCs) to produce reactive oxygen species (ROS) as evidenced by an increased level of NADPH oxidase, and an amplified ROS production in PBMCs in response to acute exercise despite lower total work performed during the exercise test, as indicated by impaired exercise performance,
(ii) increased resting cortisol and altered the plasma inflammatory proteome at rest and following acute exercise, and
(iii) reduced the exercise induced mobilization of leukocytes. Moreover, three days of refueling led to restoration of cortisol levels and inflammatory proteins to initial pre-low energy availability levels, whereas it did not restore the low energy availability induced impairment in performance (20- min time trial).
Our study illustrates a substantial impact of short-term low energy availability on the immune system, as evidenced by altered redox balance in PBMC, altered immune/inflammatory proteome and a reduced exercise-induced mobilization of PBMCs. This finding suggests that low energy availability may heighten the susceptibility to infections and disease. Additionally, our study shows that, at a functional level, low energy availability reduces endurance exercise performance, an effect which was not reversible with three days of refueling. Taken together, these findings underscore the critical importance of limiting low energy availability exposure for female athletes.
And, to help you wash down the latest evidence, here's a snifter from my recent indulgence...
Thomas Solomon’s beer of the month.
Coconut Beam.
Dugges Bryggeri (Landvetter, Sweden).
Double pastry imperial stout.
16.3% ABV. Yes, 16.3%! Boom. 
Coconutty. Chocolatety. Bourbony. Boozy. Amarettory. Beam me up, Coconutty. Get it in you, now!
RP(be)E(r)(Rating of Perceived beer Enjoyment)
9 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 science 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. Be informed. Stay educated. Think critically.
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.