Time Trial Events Research Articles

Comparative Analysis of Aerodynamic Drag Between Long Tail and Short Tail Aero Helmets Through Wind Tunnel Testing

Aerodynamic drag is a critical factor influencing the performance of competitive cyclists, particularly in time-trial events, where reducing drag can significantly improve speed and efficiency. Helmets are an essential component of aerodynamic gear, and their design plays a vital role in minimizing air resistance. However, the effect of different helmet shapes and head positions on aerodynamic performance has not been thoroughly examined. This study aims to investigate and compare the aerodynamic performance of long-tail (LT) and short-tail (ST) aero helmets, along with the Kabuto Aero SL, under varying pitch angles and speeds. Wind tunnel testing was conducted using an adult-sized mannequin head, with helmets evaluated at pitch angles ranging from 15° to 45° and wind speeds of 5 to 15 m/s. The results showed that the LT Aero helmet achieved the best performance at lower pitch angles (15°), while the ST Aero helmet performed optimally at a 25° pitch angle. The Kabuto Aero SL helmet demonstrated superior performance at low pitch positions, particularly at 15°. These findings highlight the importance of helmet design and head positioning in optimizing aerodynamic efficiency for cyclists in competitive conditions.

Experimental assessment of the effect of cyclist’s posture on comfort during time-trial events on road cycling

Experimental assessment of the effect of cyclist’s posture on comfort during time-trial events on road cycling

The design of an upper arm prosthesis utilising 3D printing conceived for the 2020 Tokyo paralympic games: A technical note.

This article describes the design and development of an upper-limb prosthesis for a current elite level paracyclist that was conceived for use in the 2020 Paralympic Games. The prosthetic limb was intended specifically for use in cycling time trial events. These are held on the road and in the velodrome whereby the athlete rides using a tucked aerodynamic position. The prosthesis was developed using computer aided design software and an extensive use of the 3D printed manufacturing process. The resulting technical note illustrates the design methodology and manufacturing considerations for a high performance form of assistive technology. However, it results in a solution that challenges the traditional aesthetic of prosthetic limbs intended for sport and physical activity.

Wearable and telemedicine innovations for Olympic events and elite sport.

Rapid advances in wearable technologies and real-time monitoring have resulted in major inroads in the world of recreational and elite sport. One such innovation is the application of real-time monitoring, which comprises a smartwatch application and ecosystem, designed to collect, process and transmit a wide range of physiological, biomechanical, bioenergetic and environmental data using cloud-based services. We plan to assess the impact of this wireless technology during Tokyo 2020, where this technology could help characterize the physiological and thermal strain experienced by an athlete, as well as determine future management of athletes during a medical emergency as a result of a more timely and accurate diagnosis. Here we describe some of the innovative technologies developed for numerous sports at Tokyo 2020 ranging from race walking (20 km and 50 km events), marathon, triathlon, road cycling (including the time trial event), mountain biking, to potentially team sports played outdoors. A more symbiotic relationship between sport, health and technology needs to be encouraged that harnesses the unique demands of elite sport (e.g., the need for unobtrusive devices that provide real-time feedback) and serves as medical and preventive support for the athlete's care. The implementation of such applications would be particularly welcome in the field of medicine (i.e., telemedicine applications) and the workplace (with particular relevance to emergency services, the military and generally workers under extreme environmental conditions). Laboratory and field-based studies are required in simulated scenarios to validate such emerging technologies, with the field of sport serving as an excellent model to understand and impact disease.

Aerodynamic drag in competitive tandem para-cycling: Road race versus time-trial positions

An athlete's riding posture is a key element for aerodynamic drag in cycling. Tandem cycling has the complication of having two athletes in close proximity to each other on a single tandem bicycle. The complex flow-field between the pilot and stoker in tandem cycling presents new challenges for aerodynamic optimisation. Aerodynamic drag acting on two tandem road race setups and two track time-trial setups were analysed with computational fluid dynamics (CFD) simulations. For validation purposes, wind tunnel measurements were designed providing drag measurements from both tandem athletes simultaneously using a quarter-scale model. A max drag force deviation of 4.9% was found between the wind tunnel experiments and CFD simulations of the quarter-scale geometry. Full-scale CFD simulations of upright, crouched, time-trial and frame-clench tandem setups were performed. The drag force experienced by individual athletes in all investigated tandem setups was compared to that of solo riders to enhance understanding of the aerodynamic interaction between both tandem athletes. The most aerodynamic tandem setup was found to be the frame-clench setup which is unique to tandem cycling and had a CDA of 0.286 m2, and could provide an advantage of 8.1 s over a standard time-trial setup for a 10 km time-trial event.

Performance Relationships in Timed and Mass-Start Events for Elite Omnium Cyclists.

To explore the extent to which factors that determine performance transfer within and between time-trial and mass-start events in the track-cycling Omnium. Official finish rank in the 3 time-trial events, in the 3 mass-start events, and in the competition overall were collated in 20 international Omnium competitions between 2010 and 2014 for 196 male and 140 female cyclists. Linear mixed modeling of the log-transformed finish time for the time-trial events and of log-transformed finish rank for all events and final rank provided estimates of within-athlete race-to-race changes in performance and average betweenathletes differences across a season. These estimates were converted to various correlations representing relationships within and between the various events and final rank. Intraclass correlation coefficients, representing race-to-race reproducibility of performance, were similar whether derived from finish rank or finish time for the time-trial events. Log-transformed finish ranks are therefore a suitable measure to assess and compare performance in time-trial and mass-start events. Omnium cyclists were more predictable in their performances from race to race in the timed events, whereas reduced predictability was observed in mass-start events. Interevent correlations indicated stronger links in performance between the timed disciplines, whereas performance in any of the mass-start events had only a slight positive relationship with performance in the other massstart events and little or no relationship with the timed events. Further investigation is warranted to determine whether factors related to performance in mass-start events can be identified to improve reproducibility or whether variability in performance results from random chance.

Aerodynamic performance and riding posture in road cycling and triathlon

Cycling performance is strongly dependent on aerodynamic drag, of which the majority is attributable to the rider. Previous studies have shown the importance of optimising athlete posture on the bicycle for individual time-trial events. This article identifies that performance in road cycling and draft-legal triathlon can be improved through aerodynamic optimisation of the athlete’s posture. Nine relevant cycling postures have been studied, and it was found that for road cycling, gripping the hoods with horizontal forearms can reduce the required cyclist power by 13.4%, and for draft-legal triathlon applications, the use of short bar extensions reduced the required power by up to 16.7%. It was also found that lowering the eyes and head increased drag in both drops and triathlon postures. Measurements of the velocity profiles of the wake of a cyclist in four different postures are presented, and it is shown that differences in drag coefficients between postures can be correlated with changes in the wake velocity defect and turbulence intensity distribution.

An experimental study on aerodynamic performance of time trial bicycle helmets

Aerodynamic efficiency is one of the important criteria for racing bicycle helmets, especially in time trial event. The physical characteristics of a bicycle helmet especially its venting geometry, position and number of vents play a crucial role in the aerodynamic efficiency of the helmet. Despite the importance of this, little information on aerodynamic behaviour of racing bicycle helmets is available. In this study, a series of commercially available time trial helmets were investigated in a wind tunnel environment over a range of wind speeds, and yaw and pitch angles to understand their aerodynamic behaviour. In order to obtain as realistic a data as possible, an instrumented mannequin was used in the wind tunnel testing. The experimental findings indicate that the aerodynamic performance of current production time trial helmets varies significantly. The results also show that helmet length as well as vent geometry and vent area have significant effects on aerodynamic drag of a time trial helmet. A time trial helmet having longer length and smooth vents with minimum vent area can reduce aerodynamic drag significantly.

The effect of an even-pacing strategy on exercise tolerance in well-trained cyclists

Previous research has suggested that the optimal pacing strategy for self-paced exercise lasting >4min is a uniform distribution of work, but this posit is not well established for prolonged endurance events. This study examined the utility of even pacing during 20km cycling time trials (TTs). Fifteen well-trained male cyclists ([Formula: see text]O2max=4.80±0.38 Lmin(-1)) completed three best effort self-paced (SP) simulated 20km TTs, followed by two even-paced trials. In one even-paced trial, participants cycled to exhaustion (EPtlim) at a fixed intensity equivalent to their best SP performance. In the other EP trial, participants were instructed to maintain this target intensity for a distance of 20km, but the actual intensity was free to vary depending on the effort and cadence of the cyclist (EP-maintained). Cardiorespiratory, blood lactate and perceptual (RPE and affect) measures were assessed throughout. Nine out of fifteen cyclists failed the EPtlim task, completing 51-83% (10.3-15.3km) of the work done in their SP trial. Failure as a result of even pacing was associated with a faster rise in blood lactate, attainment of a higher relative intensity during SP and a moderate fast starting strategy. This failure was independent of the nature of the even-paced task. By adopting an uneven, parabolic distribution of work, cyclists in this study were able to achieve an average intensity during self-paced exercise in excess of their maximum sustainable power output. A subsequent matched even-paced bout resulted in cumulative metabolic stress that could not be managed by moment-to-moment changes in power output. These results challenge the notion that strict even pacing is optimal for endurance time trial events.

The Relationship between Cortisol and Bone Mineral Density in Competitive Male Cyclists.

Objective. The purpose of this study was to determine whether race day cortisol was related to bone mineral density (BMD) in competitive male cyclists. A secondary purpose was to determine additional factors associated with BMD in competitive male cyclists. Methods. Measurements of lumbar spine and hip BMD were performed in 35 male competitors in a state championship cycling time trial event. Salivary cortisol was measured 10 minutes prior to the start of the race and 5 minutes after race finished. Participants reported daily calcium intake, age, years of bike training, races per season, and average weekly minutes spent riding a bike, weight training, and running on a survey. Results. Cortisol level increased significantly from pre- to postcompetition but was not significantly associated with BMD. Increased weekly minutes of weight training was associated with higher BMD of the lumbar spine and the hip. The increased number of years of cycling experience was associated with lower BMD of the femoral neck. Increased daily calcium intake was associated with higher BMD of the lumbar spine and femoral neck. Conclusions. Findings indicate that cyclists should participate in weight training and increase calcium intake in order to increase or maintain BMD of the lumbar spine and hip.

Time Trial Exertion Traits of Cycling's Grand Tours

We examined 26 professional riders during time trial (TT) competitions of the Grand Tours of cycling (Tour de France and Vuelta Espana; 1997-2003) for the exertional characteristics of contending vs. non-contending (i.e., support) riders. We categorized HR time during TT into training impulse (TRIMP) defined from seasonal VO2max testing [Phase I (<ventilatory threshold (VT approximately 64% VO2max); Phase II (VT-respiratory compensation threshold, approximately 83% VO2max); Phase III >RCP]. Races were: Short TT (<15 km; 8.9+/-2.9 km); Individual TT (>15 km; 48.12+/-8.7 km); Uphill TT (20.0+/-8.7 km) and Team TT (44.1+/-20.9 km). We observed statistically significant event-by-contender interactions for all TT (all, P<0.0001) except the short TT. During uphill TT, contenders exerted fewer total TRIMP (P<0.01), more Zone 3 TRIMP (P<0.05), and fewer Zone 2 TRIMP (P<0.01) vs. non-contenders. For individual TT, contenders accumulated more Total and Zone 3 TRIMP vs. non-contenders (all, P<0.05). Interestingly, during the team TT, contenders accumulated more Zone 3, and fewer Zone 2 TRIMP (all, P<0.05), despite having the opportunity to draft behind other riders while in paceline race formation. During TT events, contending riders compete at a level of exertion corresponding to a higher metabolic demand during the uphill TT, individual TT and team TT.

Exertional Characteristics of Time Trial Performance During the Grand Tours of Cycling

PURPOSE: To describe the exertional characteristics of contending (attempting to win an award) vs. non-contending riders (domestiques) during time trial (TT) competitions in the Grand Tours of cycling.FigureMETHODS: We examined 26 individual riders [age (26.5 ± 1.5 y), and VO2max (75 ± 2.5 ml·kg·min−1)] from 11 Grand Tours (Tour de France, n = 4; Vuelta Espana, n = 7) during 35 time trials (910 race exposures) consisting of short (<15 km); individual (>15 km); uphill and team TT. During each race, we categorized HR time into a TRIMP schema based on annual VO2max testing: Zone I (<ventilatory threshold (VT; ~ 70% VO2max); Zone II (VT - respiratory compensation point (RCP; ~90% VO2max); Zone III>RCP. RESULTS: We observed significant statistical effects for event type (P<0.0001), contender status (P<0.0001) and event-by-contender interaction (P<0.0001) for all TT but the short TT. Contenders were faster during the uphill and individual TT event (P p < 0.05) only. For the uphill TT, contenders accumulated fewer total TRIMP vs. noncontenders (**, 74.2 ± 12.4 vs. 99.3 ± 13.8; P < 0.01); yet more Zone 3 TRIMP (27.6 ± 10.1 vs. 0.2 ± 0.2; P < 0.05). Non-contenders accumulated more Zone 2 TRIMP (*, 44.8 ± 12.7 vs. 88.9 ± 15.1; P < 0.01). In the individual TT, contenders accumulated more Zone 3 TRIMP vs. non-contenders (*, 60.9 ± 10.6 vs. 21.6 ± 4.4; P < 0.05), as well as more total TRIMP (**, P < 0.05). For the team TT, contenders accumulated more Zone 3 TRIMP (*, 57.9 ± 8.9 vs. 36.4 ± 1.5; P < 0.01) and non-contenders more Zone 2 TRIMP (P < 0.05). CONCLUSIONS: During Grand Tours, contending riders accumulate more Zone 3 TRIMP during uphill and individual TT. Surprisingly, they accumulate more Zone 3 TRIMP during the team TT despite (theoretically) longer periods in a draft position.

The Relationship Between Power-Based Training Variables and Individual Time Trial Performance in Women's Cycling

Performance during the individual time trial and climbing events during stage races in professional road cycling often have the greatest influence on the final individual standings. However, the relationship between power-based training variables and performance in women's individual time trials during actual competition is not clear. PURPOSE: The goal of this investigation was to determine the correlation of anaerobic and aerobic power-based measures derived from training with race performances their predictive capabilities to race performance. METHODS: Power meter data from training sessions and racing during the 3 wks prior to each stage race and the competition was collected from eight international level professional female road cyclists (age = 31.1 ±3.3 yrs, mass = 56.1 ±2.8 kg) who had finished at least 4 of the 5 stage races that were part of the 2005 USCF National Racing Calendar series. The highest 1MMP (minute mean maximal power), 5MMP and 20MMP from the 3-wk period prior to each event were used to derive critical power (CP). Stepwise linear regression was conducted for each time trial with CP and 30MMP (W and W/kg) as the independent variables to determine the best predictor of performance time. Statistical significance was set at p < 0.05. RESULTS: The overall mean CP ranged from 4.2 to 4.8 W/kg while the 30MMP ranged from 4.3 to 5.0 W/kg. Critical power (W/kg) was the best predictor overall for performance time for all five of the events analyzed in the study (Race 1: adj. R2 = 0.604, p < 0.024; Race 2: 0.764, p < 0.006; Race 3: 0.704, p < 0.023; Race 4: 0.980, p < 0.001; Race 5: 0.784, p < 0.005). The standard estimate of errors (SEE) for the prediction of performance times using CP (W/kg) were ±51, ±18, ±61, ±6, and ± 10s for mean performance times of 1028 ±82, 640 ± 36, 2614 ± 112, 986 ± 39, and 465 ± 21 s, respectively. The inclusion of 30MMP (W/kg) with CP (W/kg) marginally, though significant, improved the SEE for one uphill time trial by 7 s. CONCLUSION: Critical power (W/kg) derived from power outputs produced during training and racing prior to competition was a better predictor of the uphill and hilly terrain time trial events used in this study when compared to 30MMP (W and W/kg) and CP (W). Coaches and athletes could use CP to better prepare for similar time trial events and potentially use CP as a measurement for talent identification.

Power Output Demands of Womenʼs Road Cycling Time Trial

Over the past 20 years the power output produced during many different types of cycling competition have been described (eg., cyclocross, mountain bike, track sprint, men's road and women's road). Little, if any, information is available describing the power output profiles of nationally competitive female road cyclists during the time trial. PUPPOSE: To document the cycling power output produced by nationally competitive female road cyclists during a 20-km time trial (∼30min) and to compare this power output with the maximum mean power output produced during a laboratory based 30-minute time trial (MMP30min) and the power output corresponding to VO2max (MAP). METHODS: On two successive years (Y1 and Y2) members of the Australian National Women's Road Cycling team (Y1 n=8, 25±4y, 168±4 cm, 59±3 kg, 321±20 WMAP, 63±3 ml.kg-1.min-1 VO2pk; Y2 n=6, 23±4y, 166±3 cm, 59±3 kg, 313 W MAP, 62±2, ml.kg-1·min-1 VO2pk) participated in a maximum graded exercise test (125W; inc. 25 W every 3min) and on the subsequent day a maximum 30-min laboratory time trial using a Lode electromagnetically braked cycle ergometer. Within 4 wks cyclists competed in the National Championship time trial event (∼27 km, ∼40 min) using a time trial bike fitted with a dynamically calibrated instrumented crank (SRM, 4 sg model). Power output, velocity and cadence data were sampled at 1 hz. For both years the time-trial was raced on a relatively flat course. A paired t-test was used to compare differences in power output produced in the lab and the field. RESULTS: On both years the monitored cyclist achieved top 10 results at the National Championships. The average laboratory MMP30min was similar for both years (Y1 – 265±22 W, 4.5±.4 W.kg-1; Y2 – 259±15 W, 4.3±.2 W.kg-1), a power output corresponding to 82±4% and 80±3% of the MAP. Compared to the laboratory MMP30min the average time trial power output in the field was ∼10–15W lower (Y1 – 254±15 W, p=.02; Y2 – 250±13 W, p=.01) and demonstrated greater variability. The average power output during the time trial in the field was within 3 W of the power output associated with the onset of blood lactate as calculated using the Dmax technique (Y1 – 256±25 W; Y2 – 253±21 W). CONCLUSIONS: These data are the first to document the power output produced by nationally competitive female road cyclists during a 27-km time trial in the field (>260 W or 4.5 W.kg-1 for ∼40 minutes). In the field power output tends to be lower than in the lab (approximately Dmax power) and more variable possibly due to the slightly longer effort (∼8–1 0min) and forced reductions in power output during sharp cornering in the field.

Can Anaerobic Capacity be Fully Utilized in Two Minutes of Supra-Maximal Speed Skating Exercise?

0122 Because of the limited phosphagen stores and maximal attainable lactate concentration in muscle, it is assumed that the anaerobic energy production (Ean) has a maximum: the anaerobic capacity. Two minutes of exhausting exercise is assumed to be required for maximal use of anaerobic sources. In time trial events in cycling (500–3000m), we found indications that two minutes might not be sufficient to fully utilize the anaerobic capacity. PURPOSE: To determine if the anaerobic capacity can be fully utilized in two minutes of supra-maximal exercise. METHODS: Because the nature of speed skating emphasizes the importance of the anaerobic system, elite level speed skaters (n = 8) performed a 1500m speed skating race (lasting about 2 min) and sub-maximal efficiency tests. Depending on their specialization, pairs of skaters also skated a 500m, 1000m, 3000m or 5000m. Final time is recorded for all distances. External energy production (Eext) was calculated using aerodynamic models, taking data from video analysis and ice friction measurements as input. The mechanical equivalent of aerobic energy production (Eaer) was calculated from breath-by-breath VO2 and the measured skating efficiency. Ean was determined by subtracting Eaer from Eext. The relative contribution of Ean to the total energy production was calculated (%Ean). Ean on the 500, 1000, 3000 and 5000m was related to the subject's Ean on the 1500m. RESULTS: %Ean is considerable for every skated distance. Furthermore, the results show that Ean increases with the duration of the event.TableCONCLUSION: The anaerobic contribution is substantial in all distances. The present results show that, in accordance with literature, distances < 1500m are too short to fully utilize anaerobic capacity. For the longer distances, Ean exceeds the value as measured at the 1500m, so it can be concluded that even in an exercise of highly anaerobic nature the anaerobic capacity is not fully taxed in the time span as is suggested in literature.

Maximal Lactate Steady State Rowing Intensity can be Predicted by a 6-Km Rowing Time Trial

0298 It has been suggested that endurance training at intensities approximating maximal lactate steady state (MLSS) may heighten exercise adaptations while minimizing the risk of overtraining related injuries. Measuring MLSS in the laboratory is labor intensive, as laboratory equipment, technicians, and a substantial time investment are all required for invasive physiological testing. Conversely, athletic time trial events are often completed in endurance sports and are relatively simple. If rowers were able to predict MLSS workload from a time trial, it would become comparatively simple for more athletes to become aware of their MLSS workload. PURPOSE: To test the hypothesis that a relationship exists between the average workload during a 6-km rowing time trial and the MLSS workload. METHODS: Female athletes (n = 23) from a varsity Division I collegiate rowing team were utilized as subjects (age 20.1 ± 1.1yrs, weight 72.0 ± 7.4 kg, height 162.6 ± 6.6 cm, VO2 peak 46.6 ± 3.7 ml/kg/min). Athletes underwent a maximal power output test on the rowing ergometer (max power 263.3 ± 27.5 W). To determine MLSS, each subject completed two to four 30-minute constant workload rows at intensities relative to their individual maximal power output. To eliminate test interruptions, blood samples were collected via toe stick at rest and every 5 minutes during the 30-minute rows. The criterion for achievement of MLSS was the highest concentration of blood lactate that could be maintained (± 1 mM) during the last 20 minutes of a 30-minute constant workload rows (mean MLSS 2.59 ± 0.62 mM). Subsequently, each rower completed a 6-km time trial where mean power output was recorded. RESULTS: There was a significant correlation between 6-km time trial mean power output and the power output at MLSS (r = 0.92, p<0.0001). However, 6-km time trial mean power output (214.4 ± 22.9 W) was significantly greater than the power output at MLSS (168.3 ± 19.1W). Hence, the power output at MLSS was equivalent to 78.5% of the 6-km time trial mean power output. CONCLUSIONS: The hypothesis that completion of a 6-km time trial would predict MLSS power output was supported. In rowers, as MLSS workload increases, time to complete the 6-km time trial decreases. Furthermore, this suggests that training to improve MLSS workload may improve 6-km rowing performance. Supported in part by Abbott Laboratories.

Determination of optimal pacing strategy in track cycling with an energy flow model

The purpose of this study was to investigate the effect of pacing strategies on performance times in the 1000 m time trial event and the 4000 m pursuit event in track cycling. For this purpose, we simulated these events with a model based on the flow of energy in cycling. Different strategies in distributing the available anaerobic energy were evaluated and we compared model predictions of split times and final times with values achieved by cyclists during championships. The best result at the 1000 m time trial was obtained when the cyclist had the highest anaerobic peak power output and used an 'all-out' strategy. The fastest time on the 4000 m pursuit was achieved with an 'all-out' start at a high level of initial power output, followed by a constant anaerobic power output after 12 seconds, resulting in an evenly paced race. The results show that even small variations in pacing strategy may have substantial effects on performance. There seems to be an opportunity to gain a competitive advantage when individual athletes experiment with small variations in pacing strategy to find the precise individual strategy that works best under specific conditions.

Ergogenic demands of a 24 hour cycling event.

The maximal aerobic performance (VO2 max) and energy costs of cycling at various power outputs and equivalent road speeds of a highly trained endurance cyclist (age 23.4 yrs, height 1.95 m, weight 73.1 kg), were measured in the laboratory on an eddy-current cycle ergometer, and the physiological responses related to determinations made during a 24 h cycling time trial event, using continuous ECG recording from which estimates of ergogenic demands were obtained. The cyclist covered a distance of 694 km during the event at an average speed of 28.9 km.h-1 which corresponded to an equivalent oxygen cost of 38.5 ml.kg-1 min-1 and represented approximately 55% of his VO2 max. During the event, the cyclist expended an estimated 82,680 kJ of energy, of which approximately 44,278 kJ (54%) were supplied by repeated feedings of liquids, solids and semi-solids and some 38,402 kJ (46%) came from the stored energy reserves which resulted in a 1.19 kg loss of body weight during the event. The energy demands of the activity were more than three times greater than the highest recorded values of severe industrial work, and similar to the hourly rates of expenditure of shorter duration competitive events, but above the highest values reported over other extreme endurance events over the same period of time. The results thus represent near maximal levels of sustainable ergogenic effort by man over a complete 24 h cycle.