Performance enhancement: Superhuman athletes

Thyroid function, physical activity and sedentary behaviour: A bidirectional two-sample Mendelian randomisation study

Background

The interinfluence of thyroid function and daily physical activity (PA) remains unclear. We examined the causal relationship between genetically proxied thyroid-related traits; hypothyroidism, hyperthyroidism, thyroid stimulating hormone (TSH) and free thyroxine (FT4), and daily PA measures; leisure screen time (LST) and moderate-to-vigorous physical activity (MVPA), using Mendelian randomisation (MR) analysis.

Methods

We used genome-wide association study (GWAS) data from the ThyroidOmics Consortium and the most comprehensive meta-analysis on PA, comprising data on hypothyroidism (n = 53 423), hyperthyroidism (n = 51 823), TSH within the reference range (n = 54 288), fT4 within the reference range (n = 49 269), LST (n = 526 725), and MVPA (n = 608 595) to conduct a bidirectional two-sample MR analysis. The inverse variance weighted (IVW) method was employed as the primary result. Sensitivity analyses included MR-Egger, weighted median, and MR pleiotropy residual sum and outlier (MR-PRESSO) regression. Similar investigations were conducted in the reverse direction. Finally, we analysed a multivariable MR using body mass index (BMI)-related traits GWAS data.

Results

In the primary IVW analysis, an increase in genetically proxied TSH levels significantly increased LST (correlation coefficient (β) = 0.040; 95% confidence interval (CI) = 0.020-0.061, P = 9.776 × 10-5). The multivariable MR analysis indicated that the positive causal effect still existed when considering the influence of BMI (MVMR-IVW: β = 0.042; 95% CI = 0.011-0.073, P = 0.007). Conversely, there was no evidence to suggest that PA impacts thyroid function.

Conclusions

The results of this MR analysis suggest that thyroid function influences daily PA. The positive association between TSH and LST is not confounded or mediated by BMI.

Gene doping detection in the era of genomics

Recent progress in gene editing has enabled development of gene therapies for many genetic diseases, but also made gene doping an emerging risk in sports and competitions. By delivery of exogenous transgenes into human body, gene doping not only challenges competition fairness but also places health risk on athletes. World Anti-Doping Agency (WADA) has clearly inhibited the use of gene and cell doping in sports, and many techniques have been developed for gene doping detection. In this review, we will summarize the main tools for gene doping detection at present, highlight the main challenges for current tools, and elaborate future utilizations of high-throughput sequencing for unbiased, sensitive, economic and large-scale gene doping detections. Quantitative real-time PCR assays are the widely used detection methods at present, which are useful for detection of known targets but are vulnerable to codon optimization at exon-exon junction sites of the transgenes. High-throughput sequencing has become a powerful tool for various applications in life and health research, and the era of genomics has made it possible for sensitive and large-scale gene doping detections. Non-biased genomic profiling could efficiently detect new doping targets, and low-input genomics amplification and long-read third-generation sequencing also have application potentials for more efficient and straightforward gene doping detection. By closely monitoring scientific advancements in gene editing and sport genetics, high-throughput sequencing could play a more and more important role in gene detection and hopefully contribute to doping-free sports in the future.

Thyroid Function and Physical Activity: A Population-Based Cohort Study

Background: Thyroid hormones are important metabolic regulators exerting effects in multiple systemic functions including muscular and cardiorespiratory function. Thyroid hormones may influence physical activity levels. However, there are currently no studies evaluating the association between thyroid function and physical activity levels in the general population. Methods: In a population-based cohort study between 2006 and 2013, we assessed the cross-sectional and longitudinal (with a mean follow-up time of 5 years) association of serum thyrotropin (TSH) and free thyroxine (fT4) with physical activity (metabolic equivalent task [MET] hours per week). Information on physical activity was collected using a validated questionnaire (Longitudinal Aging Study Amsterdam, median 22.50 MET hours per week). The association of TSH and fT4 with physical activity was examined using linear regression models in the cross-sectional and longitudinal analyses, adjusted for age, sex, lifestyle factors, and cardiovascular disease. In sensitivity analyses, we examined the association between thyroid function and physical activity including only participants within the reference range of thyroid function. We additionally examined moderate and vigorous physical activity separately as outcomes. Results: We included 2470 participants for the cross-sectional analysis (mean age 57.3 years, 58% women) and 1907 participants for the longitudinal analysis (mean age 56.9 years). There was no association between TSH (mIU/L) or fT4 (ng/dL) and physical activity (β = 0.65, 95% confidence interval [CI, -1.67 to 2.98] and β = 2.76, [CI -7.15 to 12.66], respectively) on cross-sectional analysis. Similarly, in the longitudinal analyses, we observed no association of TSH (β = 1.16, [CI -1.31 to 3.63]) or fT4 (β = -6.63, [CI -17.06 to 3.80]) with physical activity. Conclusions: We did not observe an association between the endogenous thyroid hormone level and total physical activity. Further studies need to be performed to evaluate whether thyroid hormone replacement therapy is associated with physical activity.

Cognitive Enhancing Drugs in Sport: Current and Future Concerns

Sporting authorities and policy makers have warned of a radical increase in the availability and use of so-called 'smart' drugs, which putatively deliver cognitive enhancements in the form of improved focus, concentration, alertness, and rapid decision-making. Although the potential for health risks is well documented when it comes to performance enhancing drugs in sport, the health implications of cognitive enhancing drugs (CEDs) remain unclear. Objectives: This article aims to provide a foundational understanding about CEDs and their application in sport. It considers what little is known about the types, nature, impact, and implications of their use for athletes and sport policy. Method: A narrative literature review was undertaken to ascertain the emerging role of CEDs beyond their clinical use to treat prescribed disorders, including the limited studies in the sporting domain. This review also considered literature pertinent to the impact of CEDs in sport and the challenges for sport policy. Results: Given the prospects of negative health impacts, policy-makers interested in preventing and controlling the use of CEDs, as well as reducing harm to athletes at all levels of performance, need guidance. This article highlights multi-faceted concerns and shines a spotlight on key issues for sporting bodies to consider regarding the critical impact that widespread use and adoption of these substances might entail. Conclusion: While the World Anti-Doping Agency (WADA) is seemingly awake to the threat posed, actions to circumvent the spread of CEDs throughout sport are nascent and require greater understanding and attention.

Computational and Complex Network Modeling for Analysis of Sprinter Athletes' Performance in Track Field Tests

Sports and exercise today are popular for both amateurs and athletes. However, we continue to seek the best ways to analyze best athlete performances and develop specific tools that may help scientists and people in general to analyze athletic achievement. Standard statistics and cause-and-effect research, when applied in isolation, typically do not answer most scientific questions. The human body is a complex holistic system exchanging data during activities, as has been shown in the emerging field of network physiology. However, the literature lacks studies regarding sports performance, running, exercise, and more specifically, sprinter athletes analyzed mathematically through complex network modeling. Here, we propose complex models to jointly analyze distinct tests and variables from track sprinter athletes in an untargeted manner. Through complex propositions, we have incorporated mathematical and computational modeling to analyze anthropometric, biomechanics, and physiological interactions in running exercise conditions. Exercise testing associated with complex network and mathematical outputs make it possible to identify which responses may be critical during running. The physiological basis, aerobic, and biomechanics variables together may play a crucial role in performance. Coaches, trainers, and runners can focus on improving specific outputs that together help toward individuals' goals. Moreover, our type of analysis can inspire the study and analysis of other complex sport scenarios.

Biology of VO2 max: looking under the physiology lamp

In this review, we argue that several key features of maximal oxygen uptake (VO₂ max) should underpin discussions about the biological and reductionist determinants of its interindividual variability: (i) training-induced increases in VO₂ max are largely facilitated by expansion of red blood cell volume and an associated improvement in stroke volume, which also adapts independent of changes in red blood cell volume. These general concepts are also informed by cross-sectional studies in athletes that have very high values for VO₂ max. Therefore, (ii) variations in VO₂ max improvements with exercise training are also likely related to variations in these physiological determinants. (iii) All previously untrained individuals will respond to endurance exercise training in terms of improvements in VO₂ max provided the stimulus exceeds a certain volume and/or intensity. Thus, genetic analysis and/or reductionist studies performed to understand or predict such variations might focus specifically on DNA variants or other molecular phenomena of relevance to these physiological pathways.

Genetic modification of the human germ line: The reasons why this project has no future

Modification of the human germ line has remained a distant but valuable objective for most biologists since the emergence of genetics (and even before). To study the historical transformations of this project, I have selected three periods - the 1930s, at the pinnacle of eugenics, around 1974 when molecular biology triumphed, and today - and have adopted three criteria to estimate the feasibility of this project: the state of scientific knowledge, the existence of suitable tools, and societal demands. Although the long-awaited techniques to modify the germ line are now available, I will show that most of the expectations behind this project have disappeared, or are considered as being reachable by highly different strategies.