Cross-country Mountain Biking Research Articles

Performance differences between 26 and 29-inch wheels in cross-country mountain biking

ABSTRACT The popularity of 29-inch mountain bike wheels for cross-country races has been increasing since 2010, but scientific studies supporting their benefits are very scarce. The aim of this study was to analyse the effect of the different bicycle version (i.e. 26 vs 29-inch) in terrain with varying inclinations. Our results indicated that for full laps, the 29” version was slightly faster than 26” version (15.92 vs. 15.74 km/h; p < .001). No differences in the power outputs for these two conditions were reported (p > .05), but a higher mean heart rate (p = .009) was obtained for the riders using the bike with the 29” wheels (167.84 vs. 167.19 bpm; p < .015). Similar results were obtained for the uphill and flat sections, however, there were no differences (p > .05) between the bikes during the downhill sections for any of the studied variables. In conclusion, the 29” version performed better on the flat or uphill terrain but their use also resulted in increased rider heart rates compared to those using the 26”-inch version; no differences were reported for the downhill terrain. This information is relevant to MTB cyclists and could help them to improve their performance.

Current Perspectives of Cross-Country Mountain Biking: Physiological and Mechanical Aspects, Evolution of Bikes, Accidents and Injuries.

Mountain biking (MTB) is a cycling modality performed on a variety of unpaved terrain. Although the cross-country Olympic race is the most popular cross-country (XC) format, other XC events have gained increased attention. XC-MTB has repeatedly modified its rules and race format. Moreover, bikes have been modified throughout the years in order to improve riding performance. Therefore, the aim of this review was to present the most relevant studies and discuss the main results on the XC-MTB. Limited evidence on the topic suggests that the XC-MTB events present a variation in exercise intensity, demanding cardiovascular fitness and high power output. Nonetheless, these responses and demands seem to change according to each event. The characteristics of the cyclists differ according to the performance level, suggesting that these parameters may be important to achieve superior performance in XC-MTB. Moreover, factors such as pacing and ability to perform technical sections of the circuit might influence general performance. Bicycles equipped with front and rear suspension (i.e., full suspension) and 29″ wheels have been shown to be effective on the XC circuit. Lastly, strategies such as protective equipment, bike fit, resistance training and accident prevention measures can reduce the severity and the number of injuries.

Aerobic and Anaerobic Power Distribution During Cross-Country Mountain Bike Racing.

To determine aerobic and anaerobic demands of mountain bike cross-country racing. Twelve elite cyclists (7 males; V˙O2max = 73.8 [2.6]mL·min-1·kg-1, maximal aerobic power [MAP] = 370 [26]W, 5.7 [0.4]W·kg-1, and 5 females; V˙O2max = 67.3 [2.9]mL·min-1·kg-1, MAP = 261 [17]W, 5.0 [0.1]W·kg-1) participated over 4 seasons at several (119) international and national races and performed laboratory tests regularly to assess their aerobic and anaerobic performance. Power output, heart rate, and cadence were recorded throughout the races. The mean race time was 79 (12) minutes performed at a mean power output of 3.8 (0.4)W·kg-1; 70% (7%) MAP (3.9 [0.4]W·kg-1 and 3.6 [0.4]W·kg-1 for males and females, respectively) with a cadence of 64 (5) rev·min-1 (including nonpedaling periods). Time spent in intensity zones 1 to 4 (below MAP) were 28% (4%), 18% (8%), 12% (2%), and 13% (3%), respectively; 30% (9%) was spent in zone 5 (above MAP). The number of efforts above MAP was 334 (84), which had a mean duration of 4.3 (1.1) seconds, separated by 10.9 (3) seconds with a mean power output of 7.3 (0.6)W·kg-1 (135% [9%] MAP). These findings highlight the importance of the anaerobic energy system and the interaction between anaerobic and aerobic energy systems. Therefore, the ability to perform numerous efforts above MAP and a high aerobic capacity are essential to be competitive in mountain bike cross-country.

The effect of 26 versus 29-inch wheel diameter in the transmission of vibrations in cross-country mountain biking

ABSTRACT Vibrations experienced by cyclists can affect their performance and health. We analysed the vibrations transmitted by mountain bike (26 or 29-inch wheels), in a 2,110 m circuit with a sample of 55 cyclists. The results indicate that the 29”-wheel increases speed (p < 0.001) and thus performance but it also increases exposure to vibrations as the root mean square (RMS) indicate (p = 0.001). The wheel diameter significantly affected the accelerometer-related dependent variables (p < 0.01), specifically seen in the RMS variable (p < 0.01). Regarding vibration transmission variables, it was found that the LW/FH, RW/FH, LA/RH, and RA/RH ratios were higher in the 29” bicycle than in 26” one. Average heart rate (p = 0.01) and maximum heart rate (p < 0.01) values were higher for the 29” bike with no significant differences in the average power values recorded. In conclusion, bicycles with 29” wheels transmit higher levels of vibration to riders.

Correlation between economy/efficiency and mountain biking cross-country race performance

ABSTRACT This study investigated the correlation between cycling economy (CE) and gross efficiency (GE) in Olympic cross-country mountain biking (XCO-MTB) race performance. Also was examined the correlation between CE, GE, and peak oxygen uptake (VO2peak). Sixteen male XCO-MTB athletes (30.9 ± 5.2 years, 68.7 ± 5.6 kg, 175.0 ± 5.7 cm, and VO2peak: 65.4 ± 4.9 mL·kg−1 min−1) completed two experimental sessions. On the first, anthropometric assessments and a maximal incremental test were performed. The maximal incremental test was performed in the cycle ergometer to determine VO2peak, CE, and GE. A week later, an XCO-MTB race was performed in the second visit, where the official race time was used as a performance indicator. An inverse, significant moderate correlation was found between race time (8318.3 ± 459.0 s) and both CE (r = −0.53; CI95% = −0.84 to −0.10; p = 0.0008), and GE (r = −0.67; CI95% = −0.89 to −0.22; p = 0.0001). However, the moderate correlation between CE and race time showed low power. No significant correlation was found between VO2peak and either CE (r = −0.45; CI95% = −0.77–0.06; p = 0.08) or GE (r = −0.47; CI95% = −0.78–0.04; p = 0.07). In conclusion, gross efficiency is an important component of XCO-MTB race performance. The VO2peak was not related to CE and GE. The evaluation of GE may be a useful addition to the battery of physiological tests in mountain bikers.

The National Interscholastic Cycling Association (NICA) Mountain Biking Injury Surveillance System (ISS): Analysis of 66,588 Student Athlete-Years of Injury Data.

Interscholastic youth cross-country mountain bike racing in the United States has grown significantly over the past decade, yet little is known about the risk profile in this age group. Aiming to protect participants, we implemented a prospective, longitudinal injury surveillance system for the purpose of better understanding youth mountain biking injuries and implementing safety measures. Data were collected during competition years 2018–2020, totaling 66,588 student athlete-years. Designated reporters from each team received weekly emails with exposure and incident report forms. Variables analyzed included demographic, rider-related, trail-related, and other data. Injury characteristics during the COVID-19 pandemic in 2020 were compared to the years 2018 and 2019. More student athletes participated in the 2020 season (25,261) than in prior seasons (18,575 in 2018 and 22,752 in 2019). During competition year 2020, overall injury proportion was lower (1.7% versus 3.0% in 2018 and 2.7% in 2019). Variables associated with injury, body part injured, type of injury, time-loss, and disposition following injury were similar between all years. Despite the pandemic and resultant changes to competition, student athletes continued to ride their bikes and become injured, but the proportion of injuries differed. This report details injury characteristics in youth mountain bike racing, including a comparison of before and during the pandemic.

Race Performance Prediction from the Physiological Profile in National Level Youth Cross-Country Cyclists.

Cross-country mountain biking is an Olympic sport discipline with high popularity among elite and amateur cyclists. However, there is a scarcity of data regarding the key determinants of performance, particularly in young cross-country cyclists. The aim of this study was to examine the physiological profile of youth national-level cross-country cyclists and to determine those variables that were able to best predict the performance in an official race. Ten youth cross-country cyclists of a national team underwent a complete evaluation that included anthropometric assessments, laboratory tests to evaluate the wattage at blood lactate thresholds and at maximal oxygen uptake (POVO2max), and field tests to make an in-depth power profile of the athletes. The data obtained in the above-mentioned tests was analysed along with total and partial race times during a competition belonging to the Union Cycliste Internationale (UCI) calendar. In the present study, large and statistically significant correlations (r = −0.67 to −0.95, p ≤ 0.05) were found between maximal and submaximal indices of aerobic fitness and cycling performance, especially when they were normalised to body mass. A multiple regression analysis demonstrated that the wattage at 2 mmol/L, 4 mmol/L and POVO2max were able to explain 82% of the variance in total race time. In summary, the results of this study support the use of maximal and submaximal indices of aerobic power as predictors of performance in youth cross-country cyclists.

Mouthguard use and attitudes regarding dental trauma among elite cross-country mountain biking and field hockey athletes.

Cross-country mountain biking and field hockey are two Olympic sports that pose a potential risk for dentofacial trauma. However, mouthguard use is not mandatory in either of these sports and knowledge about tooth rescue among athletes is often neglected. The aim of this cross-sectional epidemiological survey was to evaluate the prevalence of sports-related dentofacial injuries, mouthguard use, and attitudes regarding tooth rescue among cross-country mountain biking and field hockey athletes participating at pre-Olympic competitions held in Rio de Janeiro, Brazil. A convenience sample of 217 athletes from 33 countries participating in cross-country mountain biking (n=82; mean age=30.96±8.52years) and field hockey (n=135; mean age=19.72±2.46years) pre-Olympic competitions were examined clinically, and they answered a questionnaire regarding previous history of sports-related dentofacial injuries, attitudes toward mouthguard use, and tooth rescue. There were 120 (55.30%) males and 97 (44.70%) females who participated in the study. The prevalence of facial trauma was higher in mountain biking (54.88%) than in field hockey (26.66%, P<.001). Fracture was the most prevalent facial injury in mountain biking (80%), while laceration was the most prevalent in field hockey (30.55%). Extensive dental injuries occurred more often in mountain biking (47.37%) than in hockey (12.50%). The teeth most often affected were the maxillary central incisors in both mountain biking (57.89%) and field hockey (93.75%). Mouthguard use was more frequent among field hockey athletes (41.48%) than in mountain biking (1.22%, P<.001). The overall knowledge about tooth rescue was low, and most of the athletes in both sports did not know what to do in case of an avulsed tooth. Prevalence of dentofacial injuries among XCO-MTB and field hockey athletes participating at this pre-Olympic event was high. The majority of the athletes in this study did not use mouthguards and were unaware of recommendations in the case of an avulsed tooth.

Pacing strategy during Olympic Cross-Country Mountain Bike: effects of performance level, age and sex

Objectives: the aim of the present study was to verify the pacing strategy during a season of a Cross-Country Mountain Bike (XCO-MTB) and the effects of performance level, age and sex. Method: Overall, 802 paces in 4 age-sex categories were analyzed: male elite (EliteM; n = 272), female elite (EliteF; n = 170), male under-23 (U23M; n = 247) and female under-23 (U23F; n = 113). Races were divided into Initial Lap; middle one (Middle1); middle two (Middle2) and Final Lap. The athletes were divided into high performance (HP); intermediated performance (IP) and low performance (LP). The magnitude-based inference and the effect size were assessed to check the changes clinically important. Results: it was observed a similar fast-start strategy for all categories. Both HP EliteM and EliteF athletes showed higher speed in Final Lap than LP (EliteM - ES = 0.5; 90%CI -0.8 to -0.2; very likely and EliteF - ES = 1.0; 90%CI -1.4 to -0.6; almost certain). The U23F athletes showed higher speeds in Initial Lap than EliteF (ES = 0.21; 90%CI - 0.1 to 0.5; likely), however in Final Lap the speeds was lower in U23F (ES = 1; 90%CI -1.3 to -0.6; very likely). Conclusion: the fast-start strategy is typically used during a XCO-MTB race independently of performance level, age or sex. HP Elite athletes are able to maintain higher speeds in the Final Lap. U23F athletes used to do a more variable pacing strategy with more aggressive fast-start strategy and lower speed in Final Lap than EliteF.

The NICA injury surveillance system: Design, methodology and preliminary data of a prospective, longitudinal study of injuries in youth cross country mountain bike racing

ObjectivesTo describe the design and implementation of an injury surveillance system for youth mountain bike racing in the United States, and to report preliminary first-year results. DesignDescriptive sports injury epidemiology study. MethodsAfter two and a half years of development and extensive beta-testing, an electronic injury surveillance system went live in January, 2018. An automated email is sent to a Designated Reporter on each team, with links to the injury reporting form. Data collected include demographic information, injured body part, injury diagnosis, trail conditions and other factors associated with injury occurrence. Results837 unique injuries were reported in 554 injury events among 18,576 student-athletes. The overall injury event proportion was 3.0%. The most common injury among student-athletes was concussion/possible concussion (22.2%), followed by injuries to the wrist and hand (19.0%). Among 8,738 coaches, there were 134 unique injuries reported that occurred in 68 injury events, resulting in an overall injury event proportion of 0.8%. The shoulder (38.2%) was the most commonly injured body part among coaches. Injuries among coaches tended to more frequently result in fractures, dislocations and hospital admission compared with injuries among student-athletes. Among student-athletes, female riders sustained lower limb injuries more than male riders (34.0% vs. 20.7%, p<0.001). ConclusionsA nationwide injury surveillance system for youth mountain bike racing was successfully implemented in the United States. Overall injury event proportions were relatively low, but many injury events resulted in concussions/possible concussions, fractures, dislocations and 4 weeks or longer of time loss from riding.

Hyperproteic supplementation attenuates muscle damage after simulated Olympic cross-country mountain biking competition: a randomized case-control study

Abstract Aim: We investigated the effect of high-protein (HI-PRO - 70% protein and 30% carbohydrate) and high-carbohydrate supplementation (HI-CHO - 70% carbohydrate and 30% protein) on muscle damage, haemoglobin, immune response, perceived pain and recovery post-simulated XCO. Methods: For this,10 amateur athletes (38±9.6 yrs.) were measured pre-, post- and 24-h post-trial. Results: In comparison to the pre-trial, the post-trial athletes presented leucocytosis (p≤0.001; 14.7±6.1 and 13.6±5.6 cells x103; for HI-PRO and HI-CHO, respectively) and neutropenia (p≤0.001; 11.9±5.2 and 10.7±4.9 cells x103; for HI-PRO and HI-CHO, respectively) but recovered at 24-h post-trial (Leukocytes: 6.9±1.4 and 7.1±1.4 cells x103; for HI-PRO and HI-CHO, respectively; neutrophils: 3.6±1.2 and 3.9±1.1 cells x103; for HI-PRO and HI-CHO, respectively) without a difference between conditions (p=0.808 and p=0.531; for leukocytes and neutrophils, respectively). A similar result was observed for perceived pain and recovery, where the condition did not interfere with these variables between the o measurement moments (p=0.245 and p=0.491; for pain and recovery respectively). There was an interaction effect for lactate dehydrogenase (LDH), where HI-PRO presented a lower serum concentration 24-h post-trial compared to HI-CHO (p=0.039; 181.3±21.9 and 201.0±10.4 IU/L; for HI-PRO and HI-CHO, respectively). Conclusion: HI-PRO supplementation results in better muscle damage recovery but only for LDH. Athletes should evaluate the cost-benefit of choosing the nutrients to be consumed immediately post-training or competition.

Influence of wheel rim width on rolling resistance and off-road speed in cross-country mountain biking

ABSTRACTThe rim width of cross-country mountain bike wheel sets has increased in recent years, but the effect of this increase on performance remains unknown. The aim of this study was to analyse the influence of rim width on rolling resistance and off-road speed. We compared 3 tubeless wheel sets: 25 mm inner width as baseline, 30 mm width with the same tyre stiffness, and 30 mm width with the same tyre pressure. Three riders conducted 75 rolling resistance tests for each wheel set on a cross-country course. We determined rolling resistance using the virtual elevation method and calculated off-road speeds for flat and uphill conditions using a mathematical model. Baseline rolling resistance (Cr) was 0.0298, 90% CI [0.0286, 0.0310], which decreased by 1.4%, [0.7, 2.2] with the wider rim and the same tyre stiffness and increased by 0.9%, [0.1, 1.6] with the wider rim and the same tyre pressure. The corresponding effects on off-road speed were most likely trivial (0.0% to 0.7% faster and 0.1% to 0.6% slower, respectively). Because the effect of rim width on off-road speed seems negligible, athletes should choose the rim width that offers the best bike handling and should experiment with low tyre pressures.

Physiological determinants of elite mountain bike cross-country Olympic performance

ABSTRACTDetailed physiological phenotyping was hypothesized to have predictive value for Olympic distance cross-country mountain bike (XCO-MTB) performance. Additionally, mean (MPO) and peak power output (PPO) in 4 × 30 s all-out sprinting separated by 1 min was hypothesized as a simple measure with predictive value for XCO-MTB performance. Parameters indicative of body composition, cardiovascular function, power and strength were determined and related to XCO-MTB national championship performance (n = 11). Multiple linear regression demonstrated 98% of the variance (P < 0.001) in XCO-MTB performance (tXCO-MTB; [min]) is explained by maximal oxygen uptake relative to body mass (VO2peak,rel; [ml/kg/min]), 30 s all-out fatigue resistance (FI; [%]) and with a minor contribution from quadriceps femoris maximal torque (Tmax; [Nm]): tXCO-MTB = −0.217× VO2peak,rel.–0.201× FI+ 0.012× Tmax+ 85.4. Parameters with no additional predictive value included hemoglobin mass, leg peak blood flow, femoral artery diameter, knee-extensor peak workload, jump height, quadriceps femoris maximal voluntary contraction force and rate of force development. Additionally, multiple linear regression demonstrated parameters obtained from 4x30s repeated sprinting explained 88% of XCO-MTB variance (P < 0.001) with tXCO-MTB = −5.7× MPO+ 5.0× PPO+ 55.9. In conclusion, XCO-MTB performance is predictable from VO2peak,rel and 30 s all-out fatigue resistance. Additionally, power variables from a repeated sprint test provides a cost-effective way of monitoring athletes XCO-MTB performance.

Power Output and Pacing During International Cross-Country Mountain Bike Cycling.

To characterize the physiological profiles of elite cross-country mountain-bike (XCO-MTB) cyclists and to examine their pacing and power-output (PO) distribution during international races. Over 2 competitive seasons, 8 male XCO-MTB cyclists (VO2max 79.9 [5.2]mL·min-1·kg-1, maximal aerobic power [MAP] 411 [18]W and 6.3 [0.4]W·kg-1) regularly undertook incremental tests to assess their PO and heart rate (HR) at first and second ventilatory thresholds (VT1 and VT2) and at VO2max. During the same period, their PO, HR, speed, and cadence were recorded over 13 international races (total of 30 recorded files). Mean PO, speed, cadence, and HR during the races were 283 (22)W (4.31 [0.32]W·kg-1, 68% [5%] MAP), 19.7 (2.1)km·h-1, 68 (8)rpm, and 172 (11) beats·min-1 (91% [2%] HRmax), respectively. The average times spent below 10% of MAP, between 10% of MAP and VT1, between VT1 and VT2, between VT2 and MAP, and above MAP were 25% (5%), 21% (4%), 13% (3%), 16% (3%), and 26% (5%), respectively. Both speed and PO decreased from the start loop to lap 1 before stabilizing until the end of the race. Elite off-road cyclists demonstrated typical values of world-class endurance cyclists with an excellent power-to-mass ratio. This study demonstrated that XCO-MTB races are performed at higher intensities than reported in previous research and are characterized by a fast start followed by an even pace.

Quantification of brake data acquired with a brake power meter during simulated cross-country mountain bike racing

There is currently a dearth of information describing cycling performance outside of propulsive and physiological variables. The aim of the present study was to utilise a brake power meter to quantify braking during a multi-lap cross-country mountain bike time trial and to determine how braking affects performance. A significant negative association was determined between lap time and brake power (800.8 ± 216.4 W, mean ± SD; r = −0.446; p < 0.05), while the time spent braking (28.0 ± 6.4 s) was positively associated with lap time (314.3 ± 37.9 s; r = 0.477; p < 0.05). Despite propulsive power decreasing after the first lap (p < 0.05), lap time remained unchanged (p > 0.05) which was attributed to decreased brake work (p < 0.05) and brake time (p < 0.05) in both the front and rear brakes by the final lap. A multiple regression model incorporating braking and propulsion was able to explain more of the variance in lap time (r2 = 0.935) than propulsion alone (r2 = 0.826). The present study highlights that riders’ braking contributes to mountain bike performance. As riders repeat a cross-country mountain bike track, they are able to change braking, which in turn can counterbalance a reduction in power output. Further research is required to understand braking better.

Physiological and anthropometric characteristics of top-level youth cross-country cyclists

ABSTRACTIn the literature there is a lack of data about the development of top level athletes in cross-country mountain biking (XCO). The purpose of this study was to analyze anthropometric and physiological characteristics of some of the best XCO bikers aged between 13 and 16. The study involved 45 bikers (26 males and 19 females) belonging to a youth national team. The evaluations, consisting of anthropometric measures, incremental cycling tests (VO2max, PPO, P@RCP), and 30 s Wingate Tests (PMax, PMean), were conducted over a lapse of 4 years. Our findings showed in bikers, already at young age, a specific athletic profile advantageous for XCO performance. At the age of 16, just before entering the junior category and competing at international level, male and female bikers showed physiological values normalized to the body mass comparable to those reported in literature for high level athletes (VO2max>70 and >60 ml/kg/min, PPO >6.5 and >5.5 W/kg, respectively in males and females). The production of high power-to-weight ratios and high peaks of anaerobic power attests the presence of highly developed aerobic and anaerobic systems in young XCO cyclists reflecting the high physiological demand of this sport.

Pacing Strategy During Simulated Mountain Bike Racing

Cross-country mountain biking (XCO) is a popular high-intensity endurance cycling event, but XCO pacing strategy has not been fully examined. This study examined the pacing strategies of different XCO athletes during a laboratory-simulated XCO performance test. Brazilian cyclists classified as performance-cohort level 3 performed an XCO race simulation. The simulation consisted of four 10-km laps with a gradient of 0-10%. No group-vs-time interaction was found in lap time (P = .169), absolute (P = .719) and relative (P = .607) power output, ratings of perceived exertion (P = .182), or heart rate (P = .125). There was a time main effect, as athletes decreased power output by 0.3W/kg throughout the XCO simulation, thereby resulting in a 1.6-min decrement per lap. The power output corresponding to the onset of blood lactate accumulation adequately represented the mean power of the first lap. These results showed that 2 groups of cyclists with different training status adopted similar pacing strategies during an XCO race simulation, as they both used a fast-starting pacing strategy followed by positive pacing that resulted in a linear decrease in power output at every lap.

The effectiveness of front fork systems at damping accelerations during isolated aspects specific to cross-country mountain biking

Cross-country mountain bike suspension reportedly enhances comfort and performance through reduced vibration and impact exposure. This study analysed the effectiveness of three different front fork systems at damping accelerations during the crossing of three isolated obstacles (stairs, drop, and root). One participant completed three trials on six separate occasions in a randomised order using rigid, air-sprung, and carbon leaf-sprung forks. Performance was determined by time to cross obstacles, while triaxial accelerometers quantified impact exposure and damping response. Results identified significant main effect of fork type for performance time (p < 0.05). The air-sprung and leaf-sprung forks were significantly slower than the rigid forks for the stairs (p < 0.05), while air-sprung suspension was slower than the rigid for the root protocol (p < 0.05). There were no differences for the drop protocol (p < 0.05). Rigid forks reduced overall exposure (p < 0.05), specifically at the handlebars for the stairs and drop trials. More detailed analysis presented smaller vertical accelerations at the handlebar for air-sprung and leaf-sprung forks on the stairs (p < 0.05), and drop (p < 0.05) but not the root. As such, it appears that the suspension systems tested were ineffective at reducing overall impact exposure at the handlebar during isolated aspects of cross-country terrain features which may be influenced to a larger extent by rider technique.

A multidimensional approach to performance prediction in Olympic distance cross-country mountain bikers

ABSTRACTThis study adopted a multidimensional approach to performance prediction within Olympic distance cross-country mountain biking (XCO-MTB). Twelve competitive XCO-MTB cyclists (VO2max 60.8 ± 6.7 ml · kg−1 · min−1) completed an incremental cycling test, maximal hand grip strength test, cycling power profile (maximal efforts lasting 6–600 s), decision-making test and an individual XCO-MTB time-trial (34.25 km). A hierarchical approach using multiple linear regression analyses was used to develop predictive models of performance across 10 circuit subsections and the total time-trial. The strongest model to predict overall time-trial performance achieved prediction accuracy of 127.1 s across 6246.8 ± 452.0 s (adjusted R2 = 0.92; P < 0.01). This model included VO2max relative to total cycling mass, maximal mean power across 5 and 30 s, peak left hand grip strength, and response time for correct decisions in the decision-making task. A range of factors contributed to the models for each individual subsection of the circuit with varying predictive strength (adjusted R2: 0.62–0.97; P < 0.05). The high prediction accuracy for the total time-trial supports that a multidimensional approach should be taken to develop XCO-MTB performance. Additionally, individual models for circuit subsections may help guide training practices relative to the specific trail characteristics of various XCO-MTB circuits.

Peak oxygen uptake in a sprint interval testing protocol vs. maximal oxygen uptake in an incremental testing protocol and their relationship with cross-country mountain biking performance

In the literature, the exercise capacity of cyclists is typically assessed using incremental and endurance exercise tests. The aim of the present study was to confirm whether peak oxygen uptake (V̇O2peak) attained in a sprint interval testing protocol correlates with cycling performance, and whether it corresponds to maximal oxygen uptake (V̇O2max) determined by an incremental testing protocol. A sample of 28 trained mountain bike cyclists executed 3 performance tests: (i) incremental testing protocol (ITP) in which the participant cycled to volitional exhaustion, (ii) sprint interval testing protocol (SITP) composed of four 30 s maximal intensity cycling bouts interspersed with 90 s recovery periods, (iii) competition in a simulated mountain biking race. Oxygen uptake, pulmonary ventilation, work, and power output were measured during the ITP and SITP with postexercise blood lactate and hydrogen ion concentrations collected. Race times were recorded. No significant inter-individual differences were observed in regards to any of the ITP-associated variables. However, 9 individuals presented significantly increased oxygen uptake, pulmonary ventilation, and work output in the SITP compared with the remaining cyclists. In addition, in this group of 9 cyclists, oxygen uptake in SITP was significantly higher than in ITP. After the simulated race, this group of 9 cyclists achieved significantly better competition times (99.5 ± 5.2 min) than the other cyclists (110.5 ± 6.7 min). We conclude that mountain bike cyclists who demonstrate higher peak oxygen uptake in a sprint interval testing protocol than maximal oxygen uptake attained in an incremental testing protocol demonstrate superior competitive performance.