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The running science nerd alert.
Learn to train smart, run fast, and be strong with Thomas Solomon, PhD 
May 2025
Want the latest research on exercise science and sports nutrition? This nerd alert contains just that! Use it to help level up your running performance or coaching practice.
The studies are divided into subtopics —
training methods,
sports nutrition and hydration,
sports supplements,
athlete health (inc. mental health),
injuries and rehab,
and female athlete physiology
— but I’ve also provided a deeper insight into my favourite studies, and there’s my beer of the month to wash it all down.
My favourite papers this month.
Effects of nitrate supplements on cardiopulmonary fitness at high altitude: A meta-analysis of nine randomized controlled trials. Kang et al. (2025) PLoS One. (click the title to access the full article)
What type of study is this?
This study is
a systematic reviewA systematic review answers a specific research question by systematically collating all known experimental evidence, which is collected according to pre-specified eligibility criteria. A systematic review helps inform decisions, guidelines, and policy. with a network meta-analysisNetwork meta-analysis is a statistical method that allows for the comparison of multiple treatments simultaneously by integrating data from various studies. It uses complex statistical models to assess the effectiveness of different interventions, even when some treatments have not been directly compared in head-to-head trials.
What was the authors’ hypothesis or research question?
The authors aimed to evaluate the effects of dietary nitrate supplementation on cardiopulmonary fitness in healthy individuals performing endurance exercise at high altitude.
What did the authors do to test the hypothesis or answer the research question?
The authors conducted a meta-analysis of nine randomised controlled trials with a total sample size of 161 participants. The trials examined the effects of nitrate supplementation on biomarkers of cardiorespiratory fitness and function at high altitude. Most participants were healthy, physically active males aged 16 to 37 years, with a smaller proportion of females. The included studies involved endurance activities such as hiking, running, cycling, and trekking, all conducted at high altitudes (mostly higher than 3500 meters). The outcomes measured were plasma nitrite (NO₂⁻) levels, maximal oxygen uptake (V̇O2maxYour maximal rate of oxygen consumption; a measure of cardiorespiratory fitness and maximal aerobic power, which contributes to endurance performance.), heart rate (HR), rating of perceived exertion (RPE), and pulse oxygen saturation (SpO₂). The analysis used a random-effects model and followed PRISMA 2020 guidelines. Risk of bias was assessed using the Cochrane risk of bias (RoB2) toolThe Cochrane Risk of Bias 2 (RoB 2) tool is a standardized instrument developed by Cochrane for assessing the risk of bias in randomized controlled trials (RCTs). It is widely used to evaluate the internal validity of results from studies in a systematic review by examining bias arising from the randomization process, deviations from intended interventions, missing outcome data, the measurement of the outcome, and the selection of the reported result..
What did the authors find?
The meta-analysis found that dietary nitrate supplementation significantly increased NO₂⁻ concentrations (standardised mean difference [SMD]The standardized mean difference (SMD) is a statistical measure used to compare the means of two groups, expressed in terms of standard deviations rather than original units (e.g., the mean difference or mean change in the variable divided by the baseline standard deviation of the variable). The SMD is often used in meta-analysis because it allows researchers to combine results from studies that may use different measurement scales, providing a common metric for effect size across studies.
= 2.25, 95% confidence interval [CI]A margin of uncertainty — i.e. a plausible range of values within which the true value would be found 95% of the time if the data was repeatedly collected in different samples of people — if the range crosses zero, there is no effect.: 1.38 to 3.12, P < 0.00001; I-squared [I²]I-squared (I²) is a statistic used in meta-analysis to quantify the percentage of variation across studies that is due to heterogeneity rather than chance. A low I² value (25-50%) indicates that the findings are relatively consistent between studies, while a high I² value (>75%) suggests considerable variability among the study results, which may affect the reliability of the overall conclusions. = 70%). However, there were no statistically significant effects on VO₂max (SMD = -0.17, 95% CI: -0.58 to 0.23, P = 0.76; I² = 0%), HR (SMD = -0.04, 95% CI: -0.31 to 0.23, P = 0.77; I² = 0%), RPE (SMD = -0.16, 95% CI: -0.49 to 0.18, P = 0.36; I² = 0%), or SpO₂ (SMD = -0.08, 95% CI: -0.36 to 0.20, P = 0.58; I² = 0%). Subgroup analysis revealed potential gender-based differences in NO₂⁻ response (SMD = 2.53 for males, P = 0.05, I² = 57%), though these did not affect the other outcome measures. No evidence of publication biasPublication bias in meta-analysis occurs when studies with significant results are more likely to be published than those with non-significant findings, leading to distorted conclusions. This bias can inflate effect sizes and misrepresent the true effectiveness of interventions, making it crucial to identify and correct for it in research. was found, as confirmed by Egger’s and Begg’s tests, and trim-and-fill analyses. The authors concluded that dietary nitrate intake is not significantly associated with improvements in cardiopulmonary fitness at high altitude, although it does increase plasma nitrite levels.
What were the strengths?
This meta-analysis has several methodological strengths. It adhered to PRISMA 2020 guidelines and employed a comprehensive search strategy across multiple databases without language restrictions. Risk of bias was systematically assessed using the Cochrane risk of bias (RoB2) toolThe Cochrane Risk of Bias 2 (RoB 2) tool is a standardized instrument developed by Cochrane for assessing the risk of bias in randomized controlled trials (RCTs). It is widely used to evaluate the internal validity of results from studies in a systematic review by examining bias arising from the randomization process, deviations from intended interventions, missing outcome data, the measurement of the outcome, and the selection of the reported result.. Publication bias was explored through funnel plots, Egger’s regression, Begg’s test, and trim-and-fill analyses. Data were carefully extracted and analysed using standardised mean differences with 95% confidence intervals. Subgroup analyses were also conducted to explore potential effect modifiers such as gender.
What were the limitations?
Key limitations include the small number of studies (n=9) and relatively small pooled sample size (161 participants), which reduces statistical powerStatistical power is the probability that a statistical test will correctly reject a false null hypothesis (i.e., detect an effect if there is one). Higher power reduces the risk of a false negative (failing to detect a true effect; or a Type II error). Power is typically influenced by sample size, effect size, significance level, and variability in the data, with a common target being 80% (or 0.8).. Several studies were judged to have a high or unclear risk of biasRisk of bias in meta-analysis refers to the potential for systematic errors in the studies included in the analysis, which can lead to misleading or invalid results. Assessing this risk is crucial to ensure the reliability of the conclusions drawn from the combined data. in areas such as allocation concealment, blinding, and outcome assessment. Most participants were male and physically trained, limiting generalizability. Short intervention durations and variability in study protocols (exercise types, altitudes, nitrate doses) further limit interpretability. Furthermore, the meta-analysis protocol was not registered in PROSPERO or any pre-registration platform.
How was the study funded, and are there any conflicts of interest that may influence the findings?
This research was funded by the Health Commission of Sichuan Province, the Department of Science and Technology of Sichuan Province, the Cadre Research Health Project of Sichuan Province, and the General Hospital of Western Theater Command. The authors declared no competing interests.
Can the findings be applied to training/coaching practice?
For endurance athletes and coaches, the findings suggest that while dietary nitrate supplementation increases NO₂⁻ levels, it does not improve VO₂max, heart rate, SpO₂, or perceived exertion at high altitude. This limits its practical utility in high-altitude training or competition settings. However, the increased NO₂⁻ could be relevant in other contexts or with longer-term supplementation, and may still warrant individual experimentation under controlled conditions.
What is my Rating of Perceived scientific Enjoyment?
RP(s)E = 7 out of 10. My Rating of Perceived Scientific Enjoyment was moderate because the paper demonstrated good methodological rigour in database searching, risk of bias assessment, and evaluation of publication bias. However, it lacked pre-registration and GRADE certainty evaluation. The small number of included studies and mixed study quality reduce confidence in the findings. Nonetheless, it provides a valuable synthesis in a niche but relevant area for endurance physiology.
Important: Don’t make any major changes to your daily habits based on the findings of one study, especially if the study is small (e.g., less than 30 participants in a randomised controlled trial or less than 5 studies in a meta-analysis) or poor quality (e.g., high risk of bias or low certainty of evidence in a meta-analysis). What do other trials in this field show? (Follow the link to explore those trials.) Do they confirm the findings of this study or have mixed outcomes? Are there other high-quality systematic reviews and meta-analyses evaluating the entirety of the evidence in this field? (Follow the link to explore those reviews.) If so, what do they find? What is the risk of bias or certainty of evidence of the included studies? I’ve written a deep-dive article on this topic; check it out here.
Scroll down for the next study
Effect of different types of exercise on bone mineral density in postmenopausal women: a systematic review and network meta-analysis. Xiaoya et al. (2025) Sci Rep. (click the title to access the full article)
What type of study is this?
This study is
a systematic reviewA systematic review answers a specific research question by systematically collating all known experimental evidence, which is collected according to pre-specified eligibility criteria. A systematic review helps inform decisions, guidelines, and policy. with a network meta-analysisNetwork meta-analysis is a statistical method that allows for the comparison of multiple treatments simultaneously by integrating data from various studies. It uses complex statistical models to assess the effectiveness of different interventions, even when some treatments have not been directly compared in head-to-head trials.
What was the authors’ hypothesis or research question?
The authors aimed to evaluate and compare the effectiveness of various exercise modalities on improving bone mineral density (BMD) in postmenopausal women.
What did the authors do to test the hypothesis or answer the research question?
This study followed the PRISMA and CINeMA guidelines for systematic reviews and network meta-analyses. The authors registered their protocol in PROSPERO (CRD42023472051). A total of 49 randomised controlled trials published between 1993 and 2023 were included, encompassing 3,360 postmenopausal women. The average participant age was 60.83 years (SD = 5.87). Eight exercise types were compared: aerobic exercise, resistance training, combined aerobic and resistance training, whole-body vibration, tai chi, walking, impact exercise, and mixed exercise. The study outcomes were changes in BMD at the lumbar spine and femoral neck. The analysis used both direct and indirect comparisons, and effects were measured as mean differences (MD) with 95% credible interval (CrI)A measure of uncertainty used in Bayesian statistics. The 95% credible interval is a plausible range of values within which the true value (e.g., the true treatment effect) would be found 95% of the time if the data was repeatedly collected in different samples of people, given the data and prior information. If this range of values (the credible interval) crosses zero, there effect is not credible.. The risk of biasRisk of bias in meta-analysis refers to the potential for systematic errors in the studies included in the analysis, which can lead to misleading or invalid results. Assessing this risk is crucial to ensure the reliability of the conclusions drawn from the combined data. was assessed using Cochrane risk of bias (RoB2) toolThe Cochrane Risk of Bias 2 (RoB 2) tool is a standardized instrument developed by Cochrane for assessing the risk of bias in randomized controlled trials (RCTs). It is widely used to evaluate the internal validity of results from studies in a systematic review by examining bias arising from the randomization process, deviations from intended interventions, missing outcome data, the measurement of the outcome, and the selection of the reported result..
What did the authors find?
For lumbar spine BMD (46 studies, 2,963 women), the most effective exercise intervention was combined aerobic exercise + resistance training (mean difference [MD] = 32.35, 95% 95% CrA measure of uncertainty used in Bayesian statistics. The 95% credible interval is a plausible range of values within which the true value (e.g., the true treatment effect) would be found 95% of the time if the data was repeatedly collected in different samples of people, given the data and prior information. If this range of values (the credible interval) crosses zero, there effect is not credible. [8.08; 56.62], P-score = 0.87), followed by aerobic exercise alone (MD = 22.33, 95% CrI [6.67; 37.99], P-score = 0.74), and resistance training (MD = 16.38, 95% CrI [5.03; 27.73], P-score = 0.60). For femoral neck BMD (37 studies, 2,679 women), combined aerobic exercise + resistance training was again most effective (MD = 140.00, 95% CrI [40.89; 239.11], P-score = 0.99), followed by whole-body vibration (MD = 26.07, 95% CrI [2.97; 49.16], P-score = 0.80), and resistance training (MD = 16.98, 95% CrI [8.98; 24.99], P-score = 0.72). No statistically significant differences were found between the remaining exercise types and the control group. Funnel plots were used to assess publication biasPublication bias in meta-analysis occurs when studies with significant results are more likely to be published than those with non-significant findings, leading to distorted conclusions. This bias can inflate effect sizes and misrepresent the true effectiveness of interventions, making it crucial to identify and correct for it in research., and the certainty of the evidence was rated using CINeMA, although exact ratings were not reported in the main text. The authors concluded that combined aerobic and resistance exercise is the most effective intervention for improving bone mineral density in postmenopausal women, followed by aerobic and resistance training alone, with whole-body vibration showing additional benefits for femoral neck BMD.
What were the strengths?
The study was methodologically rigorous: it followed PRISMA guidelines, registered its protocol in PROSPERO, and used a comprehensive database search (six databases: PubMed, Embase, Cochrane, Google Scholar, Web of Science, and Scopus). The risk of bias was evaluated using Cochrane risk of bias (RoB2) toolThe Cochrane Risk of Bias 2 (RoB 2) tool is a standardized instrument developed by Cochrane for assessing the risk of bias in randomized controlled trials (RCTs). It is widely used to evaluate the internal validity of results from studies in a systematic review by examining bias arising from the randomization process, deviations from intended interventions, missing outcome data, the measurement of the outcome, and the selection of the reported result., and confidence in the findings was assessed with CINeMA. The inclusion of 49 randomised controlled trials, comprising over 3,300 participants, provided robust data for the network meta-analysis. A strength of the network approach is its capacity to integrate both direct and indirect evidence across multiple interventions.
What were the limitations?
There are several limitations. The exercise intensity and frequency were not consistently reported across studies, preventing a detailed dose-response analysis. The network suffered from imbalances, such as limited direct comparisons for some interventions like whole-body vibration and tai chi. There was also large variability in study designs and participant characteristics. The authors acknowledge that some results may have been under- or overestimated due to unmeasured confounding. Additionally, few studies included women with mobility impairments or older age, limiting generalizability.
How was the study funded, and are there any conflicts of interest that may influence the findings?
The study was supported by Henan Province Youth Natural Fund, the Henan Province Higher Education Young Backbone Teacher Training Program, and the Henan Province Postdoctoral Research Grant. The authors declared no competing financial interests or personal relationships.
Can the findings be applied to training/coaching practice?
For endurance athletes and coaches, the findings reinforce the value of resistance and aerobic training in maintaining skeletal health, which is particularly important in ageing female populations or athletes recovering from amenorrhea-related bone loss. Although targeted at postmenopausal women, the physiological principles may inform training and rehabilitation plans focused on bone health. However, these findings are more relevant for clinical populations than elite endurance athletes.
What is my Rating of Perceived scientific Enjoyment?
RP(s)E = 8 out of 10. My Rating of Perceived Scientific Enjoyment was high because the paper demonstrated strong methodological rigour, thorough reporting, and clear relevance to clinical practice. It used a well-structured network meta-analysis design and adhered to key systematic review standards. The strengths—such as a large sample size, comprehensive database coverage, and transparency via pre-registration—outweighed its limitations, which primarily related to heterogeneity and insufficient reporting of exercise parameters.
Important: Don’t make any major changes to your daily habits based on the findings of one study, especially if the study is small (e.g., less than 30 participants in a randomised controlled trial or less than 5 studies in a meta-analysis) or poor quality (e.g., high risk of bias or low certainty of evidence in a meta-analysis). What do other trials in this field show? (Follow the link to explore those trials.) Do they confirm the findings of this study or have mixed outcomes? Is there a high-quality systematic review and meta-analysis evaluating the entirety of the evidence in this field? (Follow the link to explore those reviews.) If so, what does the analysis show? What is the risk of bias or certainty of evidence of the included studies?
Scroll down for the next study
Running Economy After a Low- and High-Intensity Training Session in Naturally Menstruating Endurance-Trained Female Athletes: The FENDURA Project. Docter et al. (2025) Scand J Med Sci Sports. (click the title to access the full article)
What type of study is this?
This study is
a randomised controlled trialThe “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after the exposure to treatment/control. with crossover.Crossover means that all subjects completed all interventions (control and treatment) usually with a wash-out period in between.
What was the authors’ hypothesis or research question?
The authors aimed to evaluate whether naturally menstruating endurance-trained females could maintain running economyThe rate of energy expenditure (measured in kiloJoules [KJ], kilocalories [kcal] or oxygen consumption [V̇O2]) per kilogram bodymass (kg) per unit of distance i.e. per 1 kilometer traveled. A runner with a lower energy cost per kilometer has a higher economy than a runner with a higher energy cost. during typical low- and high-intensity training sessions, and whether the menstrual cycle phase would confound this ability.
What did the authors do to test the hypothesis or answer the research question?
The study included 24 naturally menstruating, endurance-trained female athletes aged 17–40 years. After prescreening and exclusions based on menstrual cycle verification, 16 participants completed high-intensity sessions (HIT) and 15 completed low-intensity sessions. Participants performed three low-intensity sessions and/or three HIT sessions during three distinct menstrual phases: early follicular, ovulatory, and mid-luteal. Running economy was measured before and after each session, expressed both as energy cost (kcal/kg/km) and oxygen cost (mL/kg/km). Mixed linear regression models analysed the influence of exercise and menstrual phase on running economy.
What did the authors find?
For low-intensity sessions, neither energy cost (1.34 vs. 1.35 kcal/kg/km, p = 0.762) nor oxygen cost (272 vs. 274 mL/kg/min, p = 0.128) changed significantly. For HIT sessions, energy cost remained unchanged (1.33 vs. 1.34 kcal/kg/km, p = 0.130), but oxygen cost slightly increased (269 vs. 274 mL/kg/min, p = 0.003), suggesting a small deterioration in running economy. The menstrual cycle phase did not act as a confounder as regression coefficientsThe r-value represents the correlation coefficient, which is a statistic that measures the strength and direction of a linear relationship between two variables, ranging from -1 to +1. An r value close to +1 indicates a strong positive correlation, close to -1 a strong negative correlation, and around 0 no linear relationship. changed by less than 10%. The authors concluded that running economy can be maintained during a typical 1-hour low-intensity session, and while energy cost remains stable after high-intensity sessions, oxygen cost may slightly increase. Menstrual cycle phase does not confound the ability to maintain running economy in these conditions.
What were the strengths?
The study had strong methodological rigour, including menstrual cycle phase verification using the three-step method (calendar counting, urinary ovulation testing, serum hormone analysis). The session order was randomised, and the diet and training load were carefully replicated. The protocol was also pre-registered. Furthermore, the statistical reporting was detailed, and both energy cost and oxygen cost were analysed. Lastly, participants were endurance-trained females, addressing a population often underrepresented in sports research.
What were the limitations?
The sample size was modest (n = 15–16 per session), limiting the generalizability of the results. The duration (60 minutes) and design (recovery intervals during HIT) may have been insufficient to induce large changes in running economy. No direct comparison between low-intensity sessions and HIT sessions was made (e.g., matched work output). Furthermore, the study did not explore potential inter-individual variability in the susceptibility to fatigue.
How was the study funded, and are there any conflicts of interest that may influence the findings?
This study was funded by the Tromsø Research Foundation and UiT The Arctic University of Norway via the Female Endurance Athlete (FENDURA) project. The authors explicitly declared no conflicts of interest.
Can the findings be applied to training/coaching practice?
The findings are useful for endurance athletes and coaches, particularly female athletes, by showing that 1-hour low- and high-intensity sessions do not meaningfully impair running economy. This knowledge can inform training program design without undue concern for deterioration in running economy across the menstrual cycle, promoting evidence-based training strategies inclusive of female physiology. However, due to the small sample size, further research is required to have confidence in the observed effects.
What is my Rating of Perceived scientific Enjoyment?
RP(s)E = 9 out of 10. My Rating of Perceived Scientific Enjoyment was high because the paper carefully addressed an underexplored but important question using a well-structured design, verified menstrual cycle phases accurately, and provided thorough and transparent reporting. Although the sample size was small and the practical relevance of the findings doesn’t lead to major changes in practice, the methodological robustness and focus on a neglected athlete group made it a scientifically enjoyable read.
Important: Don’t make any major changes to your daily habits based on the findings of one study, especially if the study is small (e.g., less than 30 participants in a randomised controlled trial or less than 5 studies in a meta-analysis) or poor quality (e.g., high risk of bias or low certainty of evidence in a meta-analysis). What do other studies in this field show? (Follow the link to explore those trials.) Do they confirm the findings of this study or have mixed outcomes? Is there a high-quality systematic review and meta-analysis evaluating the entirety of the evidence in this field? If so, what does the analysis show? What is the risk of bias or certainty of evidence of the included studies?
Scroll down for the next study
Continuous vertical jump test is a reliable alternative to wingate anaerobic test and isokinetic fatigue tests in evaluation of muscular fatigue resistance in endurance runners. Acar et al. (2025) BMC Sports Sci Med Rehabil. (click the title to access the full article)
What type of study is this?
This study is
a randomised controlled trial.The “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after the exposure to treatment/control.
What was the authors’ hypothesis or research question?
The authors aimed to assess whether the total work measured during the continuous vertical jump test is a valid alternative to the Wingate anaerobic power test and isokinetic fatigue test for evaluating muscular fatigue resistance. The authors also aimed to examine whether these measures correlated with half-marathon and ultra-marathon race performance.
What did the authors do to test the hypothesis or answer the research question?
The study involved 22 healthy male recreational distance runners (meanThe average of a set of numbers, calculated by summing all the values and dividing by the total number of values. age 35.23 ± 21.12 years, height 171.13 ± 21.35 cm, weight 69.49 ± 11.25 kg). Participants underwent anthropometric assessments and performed a Wingate anaerobic power test, an isokinetic fatigue test, and a vertical jump test over four laboratory visits, with 24-hour recovery periods between tests within a seven-week window. They also completed both half-marathon and ultra-marathon races, with vertical jump tests performed immediately after each race. Outcomes measured included total work during each testing modality, race times, and heart rates. Statistical analyses involved repeated measures Bland-Altman analysesA method for assessing agreement between two quantitative measurements by plotting the differences against the averages of the two measures. It identifies bias (mean difference) and limits of agreement (range where most differences fall). and intraclass correlation coefficients (ICC)The ICC is a measure of the reliability or agreement between multiple measurements or raters assessing the same target. It reflects both the degree of correlation and the agreement between measurements, with values ranging from 0 (no agreement) to 1 (perfect agreement)..to assess agreement between measures.
What did the authors find?
The study found no significant differences in total work output across Wingate anaerobic power tests, isokinetic fatigue tests, and vertical jump tests under baseline, post-half-marathon, and post-ultra-marathon conditions (p > 0.05). The total work during the vertical jump test was highly correlated with the Wingate anaerobic power test (ICC > 0.84 across conditions). Bland-Altman analyses showed 95% limits of agreementIn Bland-Altman analysis, the range within which 95% of the differences between two measurement methods are expected to fall. They are calculated as the mean difference (bias) ± 1.96 times the standard deviation of the differences. Narrow limits suggest good agreement; wide limits suggest poor agreement. ranging from 23.46% to 36.79% of Wingate anaerobic power test total work. Post-race vertical jump test total work was negatively correlated with race times and running speeds (all comparisons, p < 0.01), indicating that higher work output was associated with faster race performance. The authors concluded that the continuous vertical jump test is a valid and reliable alternative to the Wingate anaerobic test and isokinetic fatigue test for evaluating muscular fatigue resistance in endurance runners, offering a practical tool for assessing training load and performance.
What were the strengths?
The study's strengths include the use of multiple established testing methods (Wingate anaerobic power test, isokinetic fatigue test, vertical jump test) with clear descriptions, rigorous statistical analysis, high internal consistency (Cronbach’s alphaCronbach’s alpha is a statistic used to assess the internal consistency or reliability of a set of scale or test items. Values range from 0 to 1, with higher values (typically >0.7) indicating better reliability. > 0.90), the use of ICCThe ICC is a measure of the reliability or agreement between multiple measurements or raters assessing the same target. It reflects both the degree of correlation and the agreement between measurements, with values ranging from 0 (no agreement) to 1 (perfect agreement).. to confirm test-retest reliability, and comprehensive measurement across non-fatigued and fatigued conditions. The methodology also adhered to principles such as randomisation of test order, use of familiarisation sessions to reduce learning effects, and standardised protocols.
What were the limitations?
Weaknesses include a relatively small sample size (N=22), which limits generalizability, especially since only male recreational runners were included. The manual application of resistance in the Wingate anaerobic power test could also have introduced measurement inaccuracies. Additionally, the vertical jump test, being a vertical jumping test, may not perfectly model the specific neuromuscular fatigue induced by prolonged running. Furthermore, no blinding was reported, and the absence of a formal sample size calculation or protocol pre-registration diminishes methodological robustness. In addition, although reliability was high, the moderate effect sizes and large measurement error (e.g., 95% limits of agreementIn Bland-Altman analysis, the range within which 95% of the differences between two measurement methods are expected to fall. They are calculated as the mean difference (bias) ± 1.96 times the standard deviation of the differences. Narrow limits suggest good agreement; wide limits suggest poor agreement. ranging from 23.46% to 36.79% of Wingate anaerobic power test total work) suggest caution when interpreting small performance changes.
How was the study funded, and are there any conflicts of interest that may influence the findings?
No funding information is provided in the paper. The authors declared no conflicts of interest.
Can the findings be applied to training/coaching practice?
The findings are quite useful for endurance athletes and coaches. The vertical jump test provides a time-efficient and practical method to monitor muscular fatigue resistance without requiring expensive or laboratory-specific equipment like that needed for the Wingate anaerobic power test or the isokinetic fatigue test. This has direct implications for designing training programs, monitoring athlete fatigue over a season, and optimising recovery strategies. However, coaches should be cautious about over-relying on the vertical jump test alone, considering its limited sensitivity to endurance-specific fatigue.
What is my Rating of Perceived scientific Enjoyment?
RP(s)E = 6 out of 10. While I enjoyed the topic being studied and the methodology was solid in many areas, my Rating of Perceived Scientific Enjoyment was moderate because the paper lacked key elements such as protocol registration, blinding, and formal adherence to standardised reporting guidelines. Additionally, the limited sample size and population specificity reduced its scientific generalizability, and the measurement errors shown by Bland-Altman analyses diminish the confidence in the utility of the jump test over existing tools.
Important: Don’t make any major changes to your daily habits based on the findings of one study, especially if the study is small (e.g., less than 30 participants in a randomised controlled trial or less than 5 studies in a meta-analysis) or poor quality (e.g., high risk of bias or low certainty of evidence in a meta-analysis). What do other trials in this field show? (Follow the link to explore those trials.) Do they confirm the findings of this study or have mixed outcomes? Is there a high-quality systematic review and meta-analysis evaluating the entirety of the evidence in this field? If so, what does the analysis show? What is the risk of bias or certainty of evidence of the included studies? I’ve written a deep-dive article series on fatigue; check it out at veohtu.com/whatisfatigue.
All the other interesting papers I found this month are below.
Dig in and evaluate the authors’ findings by clicking on the titles to access the full papers.
Learn to critically evaluate each paper using the framework I used for my favourite papers. In doing so, aim to be sceptical, not cynical.
General training methods.
Effects of nitrate supplements on cardiopulmonary fitness at high altitude: A meta-analysis of nine randomized controlled trials. Kang et al. (2025) PLoS One. Evidence for sustained physiological adaptation between consecutive exercise bouts at simulated altitude. Joyce et al. (2025) Physiol Rep. Exploring the impact of high altitude on physiological parameters and training characteristics of endurance runners. Codella et al. (2025) J Sports Med Phys Fitness. Continuous vertical jump test is a reliable alternative to wingate anaerobic test and isokinetic fatigue tests in evaluation of muscular fatigue resistance in endurance runners. Acar et al. (2025) BMC Sports Sci Med Rehabil.Sports nutrition and hydration.
Personalized Nutrition for the Enhancement of Elite Athletic Performance. Sutehall et al. (2025) Scand J Med Sci Sports. Sports supplements.
Effects of exercise on different antioxidant enzymes and related indicators: a systematic review and meta-analysis of randomized controlled trials. Xie et al. (2025) Sci Rep. A Single Night in Hypoxia Either with or without Ketone Ester Ingestion Reduces Sleep Quality without Impacting Next-Day Exercise Performance. Stalmans et al. (2025) Med Sci Sports Exerc. Athlete health (including mental health).
Effect of different types of exercise on bone mineral density in postmenopausal women: a systematic review and network meta-analysis. Xiaoya et al. (2025) Sci Rep. Impact of moderate environmental heat stress during running exercise on circulating markers of gastrointestinal integrity in endurance athletes. Beiter et al. (2025) Physiol Rep. Injury and rehab.
Machine learning approaches to injury risk prediction in sport: a scoping review with evidence synthesis. Leckey et al. (2025) Br J Sports Med. Female athlete physiology and sex differences.
Running Economy After a Low- and High-Intensity Training Session in Naturally Menstruating Endurance-Trained Female Athletes: The FENDURA Project. Docter et al. (2025) Scand J Med Sci Sports. Influence of Sleep Quality on Recovery and Performance in Endurance and Ultra-Endurance Runners: Sex Differences Identified Through Hierarchical Clustering. Matos et al. (2025) Healthcare (Basel). Reproductive Health Management of Female Adolescent Athletes With Relative-Energy Deficiency in Sport. Romano et al. (2025) J Pediatr Adolesc Gynecol.
And, to help you wash down the latest evidence, here's a snifter from my recent indulgence...
My beer of the month.
Gingerbready Vedder.
Brewed by Brew Toon (Peterhead, Scotland).
Gingerbread tonka marshmallow stout.
8.4% ABV.
I looked in the Rear View Mirror before ordering this tipple and there she was, the Elderly Woman Behind The Counter In A Small Town. The bartender, Jeremy, poured an Even Flow of this Black stuff. After drinking, I'm now a Better Man and feel Alive.
RP(be)E(r)(Rating of Perceived beer Enjoyment)
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. Consequently, to provide access to exercise science and sports nutrition education to folks from all walks of life, I publish freely accessible high-quality exercise science and nutritional science content. This nerd alert newsletter is 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.
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.com — some of my articles contain links to information on Examine.com but I do not receive any royalties or bonuses from those links. These companies have 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.