Environmental challenges facing athletes, stakeholders and spectators at Paris 2024 Olympic and Paralympic Games: an evidence-based review of mitigation strategies and recommendations.

The upcoming Paris 2024 Olympic and Paralympic Games could face environmental challenges related to heat, air quality and water quality. These challenges will pose potential threats to athletes and impact thousands of stakeholders and millions of spectators. Recognising the multifaceted nature of these challenges, a range of strategies will be essential for mitigating adverse effects on participants, stakeholders and spectators alike. From personalised interventions for athletes and attendees to comprehensive measures implemented by organisers, a holistic approach is crucial to address these challenges and the possible interplay of heat, air and water quality factors during the event. This evidence-based review highlights various environmental challenges anticipated at Paris 2024, offering strategies applicable to athletes, stakeholders and spectators. Additionally, it provides recommendations for Local Organising Committees and the International Olympic Committee that may be applicable to future Games. In summary, the review offers solutions for consideration by the stakeholders responsible for and affected by the anticipated environmental challenges at Paris 2024.

Prehospital management of exertional heat stroke at sports competitions for Paralympic athletes.

OBJECTIVES: To adapt key components of exertional heat stroke (EHS) prehospital management proposed by the Intenational Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 so that it is applicable for the Paralympic athletes. METHODS: An expert working group representing members with research, clinical and lived sports experience from a Para sports perspective reviewed and revised the IOC consensus document of current best practice regarding the prehospital management of EHS. RESULTS: Similar to Olympic competitions, Paralympic competitions are also scheduled under high environmental heat stress; thus, policies and procedures for EHS prehospital management should also be established and followed. For Olympic athletes, the basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling and advanced clinical care. Although these principles also apply for Paralympic athletes, slight differences related to athlete physiology (eg, autonomic dysfunction) and mechanisms for hands-on management (eg, transferring the collapsed athlete or techniques for whole-body cooling) may require adaptation for care of the Paralympic athlete. CONCLUSIONS: Prehospital management of EHS in the Paralympic setting employs the same procedures as for Olympic athletes with some important alterations.

Physiology of handcycling: A current sports perspective.

Handcycling is a mode of mobility, and sport format within Para-cycling, for those with a lower limb impairment. The exercise modality has been researched extensively in the rehabilitation setting. However, there is an emerging body of evidence detailing the physiological responses to handcycling in the competitive sport domain. Competitive handcyclists utilize equipment that is vastly disparate to that used for rehabilitation or recreation. Furthermore, the transferability of findings from early handcycling research to current international athletes regarding physiological profiles is severely limited. This narrative review aims to map the landscape within handcycling research and document the growing interest at the elite end of the exercise spectrum. From 58 experimental/case studies and four doctoral theses, we provide accounts of the aerobic capacity of handcyclists and the influence training status plays; present research regarding the physiological responses to handcycling performance, including tests of sprint performance; and discuss the finite information on handcyclists' training habits and efficacy of bespoke interventions. Furthermore, given the wide variety of protocols employed and participants recruited previously, we present considerations for the interpretation of existing research and recommendations for future work, all with a focus on competitive sport. The majority of studies (n = 21) reported aerobic capacity, detailing peak rates of oxygen uptake and power output, with values >3.0 L min-1 and 240 W shown in trained, male H3-H4 classification athletes. Knowledge, though, is lacking for other classifications and female athletes. Similarly, little research is available concerning sprint performance with only one from eight studies recruiting athletes with an impairment.

Physiological responses during simulated 16 km recumbent handcycling time trial and determinants of performance in trained handcyclists.

PURPOSE: To characterise the physiological profiles of trained handcyclists, during recumbent handcycling, to describe the physiological responses during a 16 km time trial (TT) and to identify the determinants of this TT performance. METHODS: Eleven male handcyclists performed a sub-maximal and maximal incremental exercise test in their recumbent handbike, attached to a Cyclus II ergometer. A physiological profile, including peak aerobic power output (POPeak), peak rate of oxygen uptake ([Formula: see text]O2Peak), aerobic lactate threshold (AeLT) and PO at 4 mmol L-1 (PO4), were determined. Participants also completed a 16 km simulated TT using the same experimental set-up. Determinants of TT performance were identified using stepwise multiple linear regression analysis. RESULTS: Mean values of POPeak = 252 ± 9 W, [Formula: see text]O2Peak = 3.30 ± 0.36 L min-1 (47.0 ± 6.8 mL kg-1 min-1), AeLT = 87 ± 13 W and PO4 = 154 ± 14 W were recorded. The TT was completed in 29:21 ± 0:59 min:s at an intensity equivalent to 69 ± 4% POPeak and 87 ± 5% [Formula: see text]O2Peak. POPeak (r = - 0.77, P = 0.006), PO4 (r = - 0.77, P = 0.006) and AeLT (r = - 0.68, P = 0.022) were significantly correlated with TT performance. PO4 and POPeak were identified as the best predictors of TT performance (r = 0.89, P < 0.001). CONCLUSION: POPeak, PO4 and AeLT are important physiological TT performance determinants in trained handcyclists, differentiating between superior and inferior performance, whereas [Formula: see text]O2peak was not. The TT took place at an intensity corresponding to 69% POPeak and 87% [Formula: see text]O2peak.

Physiological Correlates to In-race Paratriathlon Cycling Performance.

The purpose was to determine the physiological correlates to cycling performance within a competitive paratriathlon. Five wheelchair user and ten ambulant paratriathletes undertook laboratory-based testing to determine their: peak rate of oxygen uptake; blood lactate- and ventilatory-derived physiological thresholds; and, their maximal aerobic power. These variables were subsequently expressed in absolute (l∙min -1 or W), relative (ml∙kg-1∙min -1 or W∙kg -1) and scaled relative (or ml∙kg - 0.82 ∙min -1, ml∙kg - 0.32 ∙min -1 or W∙kg -0.32) terms. All athletes undertook a paratriathlon race with 20 km cycle. Pearson's correlation test and linear regression analyses were produced between laboratory-derived variables and cycle performance to generate correlation coefficients (r), standard error of estimates and 95% confidence intervals. For wheelchair users, performance was most strongly correlated to relative aerobic lactate threshold (W∙kg -1) (r=-0.99; confidence intervals: -0.99 to -0.99; standard error of estimate=22 s). For ambulant paratriathletes, the greatest correlation was with maximal aerobic power (W∙kg -0.32) (r=-0.91; -0.99 to -0.69; standard error of estimate=88 s). Race-category-specificity exits regarding physiological correlates to cycling performance in a paratriathlon race with further differences between optimal scaling factors between paratriathletes. This suggests aerobic lactate threshold and maximal aerobic power are the pertinent variables to infer cycling performance for wheelchair users and ambulant paratriathletes, respectively.

The inflammatory response to a wheelchair half-marathon in people with a spinal cord injury - the role of autonomic function.

This study investigates the relationship between autonomic function and the inflammatory response to a wheelchair half-marathon in people with a spinal cord injury (SCI). Seventeen wheelchair athletes with a cervical SCI (CSCI, N = 7) and without CSCI (NON-CSCI, N = 10) participated in a wheelchair half-marathon. Blood was taken prior, post and 1 h post-race to determine the concentrations of adrenaline, noradrenaline, extracellular heat shock protein 72 (eHsp72) and interleukin-6 (IL-6). A sit-up tilt test was performed to assess autonomic function at rest. CSCI showed a lower supine ratio of the low and high frequency power of the variability in RR intervals (LF/HF RRI, p = 0.038), total and low frequency power of the systolic blood pressure variability (TP SBP, p < 0.001; LF SBP, p = 0.005) compared to NON-CSCI. Following the race, catecholamine concentrations increased only in NON-CSCI (p < 0.036). The increase in IL-6 post-race was larger in NON-CSCI (p = 0.040). Post-race catecholamine levels explained 60% of the variance in the IL-6 response (r = 0.77, p = 0.040), which was further increased when the resting autonomic function indices were added to the regression model (R2 > 81%, p < 0.012). In summary, the dampened acute inflammatory response to a wheelchair half-marathon in CSCI was strongly associated with the autonomic dysfunction present in this group.

The effect of pre-cooling or per-cooling in athletes with a spinal cord injury: A systematic review and meta-analysis.

OBJECTIVES: For individuals with a spinal cord injury, thermoregulatory challenges presented by the environment are amplified, increasing the risk of exertional heat illness. Thus, this systematic review and meta-analysis aims to quantify the effects of pre- and per-cooling on core temperature (Tc), skin temperature (Tsk) and thermal sensation in participants with spinal cord injury and assess the influence of lesion level on the effects of cooling. DESIGN: Systematic review with meta-analysis. METHODS: Out of 2107 potential studies, 17 were identified via the inclusion criteria for a total of 145 research participants. A total of 12 studies were included in the primary analysis of Tc; 9 included in the analysis of Tsk; and 9 included in the analysis of thermal perceptions. 15 experimental conditions were included in the secondary analysis of lesion level on the effects of cooling. RESULTS: Cooling reduced Tc (Hedges' g = 0.44; 95% confidence intervals 0.16, 0.72; p < 0.001), Tsk (Hedges' g = 1.11; 95% confidence intervals 0.56, 1.66; p < 0.002) and thermal sensation (Hedges' g = 0.60; 95% confidence intervals 0.27, 0.93; p < 0.001). Subgroup analysis revealed pre-cooling (Hedges' g = 0.92), reduced Tc to a greater extent than per-cooling (Hedges' g = 0.25; p = 0.020). The effect of lesion level on the effectiveness of cooling on Tc had a moderate, positive association (r = 0.518, p = 0.048). CONCLUSION: Pre-cooling may reduce Tc to a greater extent than per-cooling during subsequent exercise. Pre- and per-cooling can attenuate the increase in thermal strain in athletes with a spinal cord injury. The beneficial effects of cooling are greater in tetraplegic individuals.

Ice Slurry Ingestion Lowers Thermoregulatory Strain in Wheelchair Tennis Players During Repeated Sprint Intervals in the Heat.

PURPOSE: To examine the efficacy of per-cooling via ice slurry ingestion (ICE) in wheelchair tennis players exercising in the heat. METHOD: Eight wheelchair tennis players undertook sprints (4 sets of 10 × 5 s over 40 min) in a hot environment (∼32 °C), interspersed by 3 boluses of 2.67 g·kg (6.8 g·kg total) ICE or drinking temperate water (control condition). Athletes performed an on-court test of repeated sprint ability (20 × 20 m) in temperate conditions immediately before and 20 minutes after the heat exposure, and time to complete each sprint as well as intermediate times were recorded. Gastrointestinal and weighted mean skin and forehead temperatures were collected throughout the heat exposure, as were thermal sensation, heart rate, and blood lactate concentration. Sweat rate was calculated from body mass changes and fluid/ice intakes. RESULTS: Compared with the control condition, ICE resulted in a significantly lower gastrointestinal temperature (95% CI, 0.11-0.17 °C; P < .001), forehead temperature (0.58-1.06 °C; P < .001), thermal sensation (0.07-0.50 units; P = .017), and sweat rate (0.06-0.46 L·h-1; P = .017). Skin temperature, heart rate, and blood lactate concentration were not significantly different between conditions (P ≥ .598). There was no overall change preheating to postheating (P ≥ .114) or an effect of condition (P ≥ .251) on repeated sprint times. CONCLUSIONS: ICE is effective at lowering objective and subjective thermal strain when consumed between sets of repeated wheelchair sprints in the heat. However, ICE has no effect on on-court repeated 20-m sprint performance.

High Thermoregulatory Strain During Competitive Paratriathlon Racing in the Heat.

PURPOSE: Paratriathletes may display impairments in autonomic (sudomotor and/or vasomotor function) or behavioral (drinking and/or pacing of effort) thermoregulation. As such, this study aimed to describe the thermoregulatory profile of athletes competing in the heat. METHODS: Core temperature (Tc) was recorded at 30-second intervals in 28 mixed-impairment paratriathletes during competition in a hot environment (air temperature = 33°C, relative humidity = 35%-41%, and water temperature = 25°C-27°C), via an ingestible temperature sensor (BodyCap e-Celsius). Furthermore, in a subset of 9 athletes, skin temperature was measured. Athletes' wetsuit use was noted while heat illness symptoms were self-reported postrace. RESULTS: In total, 22 athletes displayed a Tc ≥ 39.5°C with 8 athletes ≥40.0°C. There were increases across the average Tc for swim, bike, and run sections (P ≤ .016). There was no change in skin temperature during the race (P ≥ .086). Visually impaired athletes displayed a significantly greater Tc during the run section than athletes in a wheelchair (P ≤ .021). Athletes wearing a wetsuit (57% athletes) had a greater Tc when swimming (P ≤ .032), whereas those reporting heat illness symptoms (57% athletes) displayed a greater Tc at various time points (P ≤ .046). CONCLUSIONS: Paratriathletes face significant thermal strain during competition in the heat, as evidenced by high Tc, relative to previous research in able-bodied athletes and a high incidence of self-reported heat illness symptomatology. Differences in the Tc profile exist depending on athletes' race category and wetsuit use.

Heat-related issues and practical applications for Paralympic athletes at Tokyo 2020.

International sporting competitions, including the Paralympic Games, are increasingly being held in hot and/or humid environmental conditions. Thus, a greater emphasis is being placed on preparing athletes for the potentially challenging environmental conditions of the host cities, such as the upcoming Games in Tokyo in 2020. However, evidence-based practices are limited for the impairment groups that are eligible to compete in Paralympic sport. This review aims to provide an overview of heat-related issues for Paralympic athletes alongside current recommendations to reduce thermal strain and technological advancements in the lead up to the Tokyo 2020 Paralympic Games. When competing in challenging environmental conditions, a number of factors may contribute to an athlete's predisposition to heightened thermal strain. These include the characteristics of the sport itself (type, intensity, duration, modality, and environmental conditions), the complexity and severity of the impairment and classification of the athlete. For heat vulnerable Paralympic athletes, strategies such as the implementation of cooling methods and heat acclimation can be used to combat the increase in heat strain. At an organizational level, regulations and specific heat policies should be considered for several Paralympic sports. Both the utilization of individual strategies and specific heat health policies should be employed to ensure that Paralympics athletes' health and sporting performance are not negatively affected during the competition in the heat at the Tokyo 2020 Paralympic Games.

Mixed Active and Passive, Heart Rate-Controlled Heat Acclimation Is Effective for Paralympic and Able-Bodied Triathletes.

Purpose: The aims of this study are to explore the effectiveness of mixed active and passive heat acclimation (HA), controlling the relative intensity of exercise by heart rate (HR) in paratriathletes (PARA), and to determine the adaptation differences to able-bodied (AB) triathletes. Methods: Seven elite paratriathletes and 13 AB triathletes undertook an 8-day HA intervention consisting of five HR-controlled sessions and three passive heat exposures (35°C, 63% relative humidity). On the first and last days of HA, heat stress tests were conducted, whereby thermoregulatory changes were recorded during at a fixed, submaximal workload. The AB group undertook 20 km cycling time trials pre- and post-HA with performance compared to an AB, non-acclimated control group. Results: During the heat stress test, HA lowered core temperature (PARA: 0.27 ± 0.32°C; AB: 0.28 ± 0.34°C), blood lactate concentration (PARA: 0.23 ± 0.15 mmol l-1; AB: 0.38 ± 0.31 mmol l-1) with concomitant plasma volume expansion (PARA: 12.7 ± 10.6%; AB: 6.2 ± 7.7%; p ≤ 0.047). In the AB group, a lower skin temperature (0.19 ± 0.44°C) and HR (5 ± 6 bpm) with a greater sweat rate (0.17 ± 0.25 L h-1) were evident post-HA (p ≤ 0.045), but this was not present for the PARA group (p ≥ 0.177). The AB group improved their performance by an extent greater than the smallest worthwhile change based on the normal variation present with no HA (4.5 vs. 3.7%). Conclusions: Paratriathletes are capable of displaying partial HA, albeit not to same extent as AB triathletes. The HA protocol was effective at stimulating thermoregulatory adaptations with performance changes noted in AB triathletes.

Brief Report: Training Load, Salivary Immunoglobulin A, and Illness Incidence in Elite Paratriathletes.

PURPOSE: To gain an exploratory insight into the relation between training load (TL), salivary secretory immunoglobulin A (sIgA), and upper respiratory tract illness (URI) in elite paratriathletes. METHODS: Seven paratriathletes were recruited. Athletes provided weekly saliva samples for the measurement of sIgA over 23 consecutive weeks (February to July) and a further 11 consecutive weeks (November to January). sIgA was compared to individuals' weekly training duration, external TL, and internal TL, using time spent in predetermined heart-rate zones. Correlations were assessed via regression analyses. URI was quantified via weekly self-report symptom questionnaire. RESULTS: There was a significant negative relation between athletes' individual weekly training duration and sIgA secretion rate (P = .028), with changes in training duration accounting for 12.7% of the variance (quartiles: 0.2%, 19.2%). There was, however, no significant relation between external or internal TL and sIgA parameters (P ≥ .104). There was no significant difference in sIgA when URI was present or not (101% vs 118% healthy median concentration; P ≥ .225); likewise, there was no difference in sIgA when URI occurred within 2 wk of sampling or not (83% vs 125% healthy median concentration; P ≥ .120). CONCLUSIONS: Paratriathletes' weekly training duration significantly affects sIgA secretion rate, yet the authors did not find a relation between external or internal TL and sIgA parameters. Furthermore, it was not possible to detect any link between sIgA and URI occurrence, which throws into question the potential of using sIgA as a monitoring tool for early detection of illness.

A Multi-Factorial Assessment of Elite Paratriathletes' Response to Two Weeks of Intensified Training.

PURPOSE: In able-bodied athletes, several hormonal, immunological and psychological parameters are commonly assessed in response to intensified training due to their potential relationship to acute fatigue and training/non-training stress. This has yet to be studied in Paralympic athletes. METHODS: Ten elite paratriathletes were studied for five weeks around a 14-day overseas training camp whereby training load was 137% of pre-camp levels. Athletes provided: six saliva samples (one pre-camp, four during camp, one post-camp) for cortisol, testosterone and secretory immunoglobulin A; weekly psychological questionnaires (POMS and RESTQ-S); daily resting heart rate and subjective wellness measures including sleep quality and quantity. RESULTS: There was no significant change in salivary cortisol, testosterone, cortisol:testosterone ratio or secretory immunoglobulin A during intensified training (p≥0.090). Likewise, there was no meaningful change in resting heart rate or subjective wellness measures (p≥0.079). Subjective sleep quality and quantity increased during intensified training (p≤0.003). There was no significant effect on any POMS subscale other than lower anger (p=0.049) whilst there was greater general recovery and lower sport and general stress from RESTQ-S (p≤0.015). CONCLUSIONS: There was little to no change in parameters commonly associated with the fatigued state which may relate to the training camp setting minimising external life stresses and the careful management of training loads from coaches. This is the first evidence of such responses in Paralympic athletes.

Qualitative release assessment to estimate the likelihood of henipavirus entering the United Kingdom.

The genus Henipavirus includes Hendra virus (HeV) and Nipah virus (NiV), for which fruit bats (particularly those of the genus Pteropus) are considered to be the wildlife reservoir. The recognition of henipaviruses occurring across a wider geographic and host range suggests the possibility of the virus entering the United Kingdom (UK). To estimate the likelihood of henipaviruses entering the UK, a qualitative release assessment was undertaken. To facilitate the release assessment, the world was divided into four zones according to location of outbreaks of henipaviruses, isolation of henipaviruses, proximity to other countries where incidents of henipaviruses have occurred and the distribution of Pteropus spp. fruit bats. From this release assessment, the key findings are that the importation of fruit from Zone 1 and 2 and bat bushmeat from Zone 1 each have a Low annual probability of release of henipaviruses into the UK. Similarly, the importation of bat meat from Zone 2, horses and companion animals from Zone 1 and people travelling from Zone 1 and entering the UK was estimated to pose a Very Low probability of release. The annual probability of release for all other release routes was assessed to be Negligible. It is recommended that the release assessment be periodically re-assessed to reflect changes in knowledge and circumstances over time.

Assessing the risks of West Nile virus-infected mosquitoes from transatlantic aircraft: implications for disease emergence in the United Kingdom.

The number of West Nile virus (WNV)-infected mosquitoes aboard aircraft from the United States that arrive in the United Kingdom each summer was determined using a quantitative risk assessment. In the worst-case scenario, when WNV levels in mosquitoes are high (at epidemic levels) the probability of at least one WNV-infected mosquito being introduced into the United Kingdom was predicted to be 0.99. During these periods, a mean of 5.2 infected mosquitoes were estimated to be aboard flights from the United States to the United Kingdom during May to October, with 90% certainty that the exact value lies between one and ten mosquitoes. Heathrow airport was predicted to receive the majority of the infected mosquitoes (72.1%). Spatial analysis revealed the region surrounding Heathrow satisfies the criteria for potential WNV exposure as both WNV-competent mosquitoes and susceptible wild bird species are present. This region is, therefore, recommended for targeted, risk-based surveillance of WNV-infected mosquitoes in addition to an increased awareness of the risks to horses, birds and humans.