10-km Run Research Articles

The Effect of an Olympic Distance Triathlon on Pulmonary Diffusing Capacity and its Recovery 24 Hours Later.

The Olympic distance triathlon includes maximal exercise bouts with transitions between the activities. This study investigated the effect of an Olympic distance triathlon (1.5-km swim, 40-km bike, 10-km run) on pulmonary diffusion capacity (DLCO). In nine male triathletes (age: 24 ± 4.7 years), we measured DLCO and calculated the DLCO to alveolar volume ratio (DLCO/VA) and performed spirometry testing before a triathlon (pre-T), 2 hours after the race (post-T), and the day following the race (post-T-24 h). DLCO was measured using the 9-s breath-holding method. We found that (1) DLCO decreased significantly between pre- and post-T values (38.52 ± 5.44 vs. 35.92 ± 6.63 ml∙min-1∙mmHg-1) (p < 0.01) and returned to baseline at post-T-24 h (38.52 ± 5.44 vs. 37.24 ± 6.76 ml∙min-1∙mmHg-1, p > 0.05); (2) DLCO/VA was similar at the pre-, post- and post-T-24 h DLCO comparisons; and (3) forced expiratory volume in the first second (FEV1) and mean forced expiratory flow during the middle half of vital capacity (FEF25-75%) significantly decreased between pre- and post-T and between pre- and post-T-24-h (p < 0.02). In conclusion, a significant reduction in DLCO and DLCO/VA 2 hours after the triathlon suggests the presence of pulmonary interstitial oedema. Both values returned to baseline 24 hours after the race, which reflects possible mild and transient pulmonary oedema with minimal physiological significance.

Relationship of critical speed derived from a 10-min submaximal treadmill test to 5-km and 10-km running performances.

It has been shown that the critical speed (CS) predicted from a perceptually self-regulated 10-min submaximal treadmill test (T10) is reliable and closely matches the CS estimated from conventional methods. To assess the relationship between the T10 and 5-km and 10-km running performances, 36 recreational runners (mean SD: age: 32.2 ± 6.2 years, height: 173.2 ± 7.3cm, weight: 70.9 ± 8.8kg, maximal oxygen uptake (V̇O2max): 53.3 ± 6.1mL·kg-1·min-1) performed a ramp incremental test and 2 T10 tests (the first as a familiarization trial). Results showed that the T10 CS (3.9 ± 0.44 m·s-1) was significantly correlated with runners' last 6months best performances in 5km (20.3 ± 2.7min; r = -0.90) and 10km (42.7 ± 5.7min; r = -0.91), the V̇O2max (r = 0.75), the speed associated with the gas exchange threshold (vGET: 3.38 ± 0.36 m·s-1; r = 0.76), the speed associated with the second ventilatory threshold (vVT2: 4.15 ± 0.49 m·s-1; r = 0.84), and the speed associated with the V̇O2max (vV̇O2max: 4.78 ± 0.54 m·s-1; r = 0.87). Moreover, 79% and 83% of the variance in 5-km and 10-km performances could be explained solely by the CS predicted from the T10. Results evidenced the strong relationship and practical performance relevance of the T10 CS test. Novelty: Critical speed derived from a 10-min submaximal treadmill test (T10) is significantly correlated with 5-km and 10-km running performances. The T10 critical speed test may represent a useful tool for assessing running performance capabilities.

Effects of standing and walking on plantar pressure distribution in recreational runners before and after long-distance running

With marathon-running grew in popularity, the effect of long-distance running on plantar pressure has been more attractive. It has been proposed that long-distance running influences the deviation in the center of pressure (COP) during standing and the changes to plantar pressure during walking. The objective of this study was to observe the effects on the COP motion amplitude of static standing and the plantar pressure distribution of walking after long-distance running. The influence of a 10-km run on changes to plantar pressure was assessed during standing and walking. Plantar pressure was measured before and immediately after running. In the study, seven males and five females participated in barefoot tests of static standing and dynamic walking. In the static standing tests, COP was measured under the following four ordered conditions: (1) bipedal, eyes open, standing; (2) bipedal, eyes closed, standing; (3) unipedal, eyes open, standing and (4) unipedal, eyes closed, standing. Under each condition, the data was collected while a stable standing posture for 10 s. In the dynamic walking tests, the contact duration and plantar pressure were recorded. The standing tests results revealed no significant differences between males and females while slight differences before vs. after running. Running for a single time had no effect on COP deviation during standing. The walking tests results revealed an initial landing on the lateral heel. After landing on the lateral heel, the females quickly transferred to the medial heel. The movement of the pressure to the medial heel was slower in males than females. After running, the pressure of females was more inward, while that of males was more outward under the metatarsal zones in the propulsion phase.

English

Background: Long distance practice running are growing and nutritional ergogenic are commonly used as a potential aid in final training and competition performance. Caffeine (CAF) and carbohydrates (CHO) are among the most commonly used supplements due to their expected ergogenic properties that can optimize energetic systems. The objective of this study was to examine potential changes in 10-km running performance with acute isolated and combined CAF and CHO supplementation. Material and method: Fifteen recreational endurance-trained runners performed four 10-km running performance on an official athletic track (400 m) under four supplementation conditions: placebo and placebo (PLA+PLA), placebo and caffeine (PLA+CAF), placebo and carbohydrates (PLA+CHO), caffeine and carbohydrates (CAF+CHO). CAF and CHO supplementation consisted of capsules of 6 mg·kg-1 and 8% CHO solution (1 g·kg-1) respectively, ingested 60 and 30 minutes before the performance tests. Placebo was obtained through empty capsules for CAF and juice for CHO without sugar (Clight®). During each trial running speed to calculate 10-km mean velocity (MV) and maximum heart rate (HRmax) were analyzed. Results: There was a difference in the pacing strategy adopted by the runners with higher MV during the initial phase for PLA+CAF and CAF+CHO groups and in the final phase for PLA+ CHO. However, there was no statistically significant difference in 10-km running performance between the conditions, as well as for HRmax. Conclusions: The use of acute, isolated and combined CAF+CHO supplementation had influence in the pacing strategy, but no in 10- km final performance, of recreational runners.

Changes in ankle work, foot work, and tibialis anterior activation throughout a long run

BackgroundThe ankle and foot together contribute to over half of the positive and negative work performed by the lower limbs during running. Yet, little is known about how foot kinetics change throughout a run. The amount of negative foot work may decrease as tibialis anterior (TA) electromyography (EMG) changes throughout longer-duration runs. Therefore, we examined ankle and foot work as well as TA EMG changes throughout a changing-speed run. MethodsFourteen heel-striking subjects ran on a treadmill for 58 min. We collected ground reaction forces, motion capture, and EMG. Subjects ran at 110%, 100%, and 90% of their 10-km running speed and 2.8 m/s multiple times throughout the run. Foot work was evaluated using the distal rearfoot work, which provides a net estimate of all work contributors within the foot. ResultsPositive foot work increased and positive ankle work decreased throughout the run at all speeds. At the 110% 10-km running speed, negative foot work decreased and TA EMG frequency shifted lower throughout the run. The increase in positive foot work may be attributed to increased foot joint work performed by intrinsic foot muscles. Changes in negative foot work and TA EMG frequency may indicate that the TA plays a role in negative foot work in the early stance of a run. ConclusionThis study is the first to examine how the kinetic contributions of the foot change throughout a run. Future studies should investigate how increases in foot work affect running performance.

Acute caffeine mouth rinsing does not improve 10-km running performance in CYP1A2 C-allele carriers.

This study assessed whether caffeine mouth rinsing affects 10-km run performance and vertical jump in recreational runners. A double-blind, placebo-controlled, crossover study was conducted. Ten well-trained volunteers performed two trials, following caffeine or placebo mouth rinse, separated by seven days. Immediately before the 10-km run, a 10-second mouth rinse with either 300mg of caffeine (1.2%) or microcrystalline cellulose (placebo) diluted in 25mL of water was performed. Pre- and post-exercise, participants performed a vertical jump test. A Garmin Forerunner® GPS, was used to measure 10-km running time and an 11-point Borg scale was used post-exercise to measure ratings of perceived exertion. Blood samples were also collected during the visit in the laboratory in the afternoon period to classify individuals according to their CYP1A2 genotype. Vertical jump performance was evaluated using a force plate. Nine runners (90%) were CC homozygotes and one (10%) was an AC heterozygote for CYP1A2. There was no difference in 10-km time-trial performance (Placebo: 47.07±5.18 vs. CAF: 47.45±6.34min, p=0.89), ratings of perceived exertion (Placebo: 17±1 vs. CAF: 16±2, p=0.34) or vertical jump power (Placebo, Pre: 4.5±0.6W•kg-1 and Post: 4.5±0.7W•kg-1; CAF: Pre: 4.4±0.7W•kg-1 and Post: 4.4±0.8W•kg-1, d=0.21, p=0.66) between trials. Acute caffeine mouth rinsing (1.2%) did not improve 10-km performance and showed similar null effects on vertical jump performance in CYP1A2 C-allele carriers.

Running Your Best Triathlon Race.

Negative or evenly paced racing strategies often lead to more favorable performance outcomes for endurance athletes. However, casual inspection of race split times and observational studies both indicate that elite triathletes competing in Olympic-distance triathlon typically implement a positive pacing strategy during the last of the 3 disciplines, the 10-km run. To address this apparent contradiction, the authors examined data from 14 International Triathlon Union elite races over 3 consecutive years involving a total of 725 male athletes. Analyses of race results confirm that triathletes typically implement a positive running pace strategy, running the first lap of the standard 4-lap circuit substantially faster than laps 2 (∼7%), 3 (∼9%), and 4 (∼12%). Interestingly, mean running pace in lap 1 had a substantially lower correlation with 10-km run time (r = .82) than both laps 2 and 3. Overall triathlon race performance (ranking) was best associated with run performance (r = .82) compared with the swim and cycle sections. Lower variability in race pace during the 10-km run was also reflective of more successful run times. Given that overall race outcome is mainly explained by the 10-km run performance, with top run performances associated with a more evenly paced strategy, triathletes (and their coaches) should reevaluate their pacing strategy during the run section.

A Combined Approach for Health Assessment in Adolescent Endurance Runners.

Background: It has been shown that prolonged exhaustive exercise, such as half-marathon running, could lead to transient post-exercise elevation of cardiac troponins, increase in oxidative stress, and mild decline in renal function in adolescent athletes. With increases in sports participation involving young people, there has been much interest in pre and post health evaluations following exercise. Evaluations can be used to identify pre-existing health confounders and to examine any detrimental responses that may occur post exercise. Study purpose & Methods: The purpose of this study was to evaluate pre and post exercise measures of cardiac function, serum albumin, systemic immunoglobulin (Serum IgA and IgG), cortisol and testosterone in adolescent (age: 16.2 ± 0.6) male endurance runners performing in 21-km maximal run. Results: Results revealed that cortisol, IgA and IgG levels significantly decreased 2, 4, and 24 h post exercise compared to pre-exercise levels (p < 0.05). Testosterone levels reduced 4 h post exercise (p < 0.05) but were restored to baseline values following 24 h. There were no changes recorded for albumin levels post exercise (p > 0.05). ECG assessments did not show any abnormalities at the T wave axis, ST segments and Q wave pre or post exercise. Conclusions: The findings from this study suggest that a single bout of prolonged maximum running is not likely to induce abnormal electrical activity in the heart, but does decrease serum immunoglobulin, and homeostasis of anabolic and catabolic hormones in trained adolescent endurance runners.

10 km performance prediction by metabolic and mechanical variables: influence of performance level and post-submaximal running jump potentiation

ABSTRACT We aimed to develop models to explain performance and pacing during a 10-km running trial. Well-trained runners (n = 27, VO2max = 62.3 ± 4.5 mL·kg−1·min−1) divided into High (HPG, T10km = 33.9 ± 1.2 min, n = 9) and Low (LPG, T10km = 37.9 ± 1.2 min, n = 18) performers completed, in different days, the half squat and loaded squat jump (LSJ) exercises (1st day), an incremental test and a submaximal running bout to induce jump potentiation (2nd day), and a 10-km time trial (3rd day). Pacing was significantly different between performance groups (p < 0.05). The inclusion of mechanical and metabolic variables increased the explained variance in performance (LPG, r2adj = 0.87, p < 0.001; HPG, r2adj = 0.99 p < 0.01). Analysis between potentiation and non-potentiation groups revealed significant differences for the speed in the last 400 m (p = 0.02), and in the final RPE (p = 0.03). Performance and pacing can be explained by combining metabolic and mechanical variables and should be controlled by performance level. The relationship between jump potentiation and speed during the last 400 m may suggest that post-activation performance enhancement could be involved in pacing regulation.

Correlation Between Inflammatory and Epigenetic Marks With Aerobic Performance in 10-km Runners

ABSTRACT Purpose: Our goals were to evaluate the effect of a 10-km running trial on inflammatory and epigenetic markers of 10-km runners and correlate the biochemical findings with anthropometric variables and performance. Methods: Twenty trained 10-km runners and seven sedentary male volunteers were recruited. Venous blood samples were collected at different times: under resting conditions, before the 10 Km race, and immediately after the finish. Inflammatory markers (IL-6, IL-10, and IL-β) and cortisol levels were evaluated in plasma, while DNA methyltransferases (DNMT1 and DNMT3b) contents were measured in peripheral blood mononuclear cells (PBMCs). Results: Higher levels of plasma IL-6 levels were observed in 10-km runners compared to the sedentary group. After the trial, the runners had a significant increase on IL-6, IL-10, and cortisol plasma levels compared to baseline. Conclusion: Our findings suggest that inflammatory profile, but not DNMT content, influences aerobic performance in 10-km runners.

Associations between Vpeak, vLT and 10-km running performance in recreational runners

The main aim of the present study was to verify which variable, between peak running velocity (Vpeak) and the velocity at lactate threshold (vLT), better correlates with 10-km running performance. The second aim was to demonstrate the association between these two variables (Vpeak and vLT). Seventeen male, recreational, endurance-trained runners perfomed three tests: incremental exercise test to determine Vpeak and other for vLT determination by maximal deviation method (Dmax), and 10-km running performance. Incremental tests were performed on the treadmill and the 10-km running test on the outdoor track. Incremental tests started with a velocity of 8 km·h−1, which increased by 1 km·h−1 between each successive 3-min stage until exhaustion. For vLT determination it was required pauses for blood samples collection. It was found that both Vpeak and vLT were highly correlated with 10-km mean velocity (MV10-km) (r = 0.92 and 0.81, respectively). It was found a high association between Vpeak and vLT (r = 0.91). Both Vpeak and vLT were highly associated with MV10-km, in which Vpeak better correlates with performance. In addition, Vpeak and vLT were highly related to each other. In practical application, coaches and runners should use both Vpeak and vLT as parameters to prescribe and monitor running training to provide valuable information on the progress of training and its control.

The effect of an Olympic distance triathlon on the respiratory muscle strength and endurance in triathletes.

High-intensity exercise, marathons, and long distances triathlons have been shown to induce the fatigue of respiratory muscles (RMs). Never-theless, fatigue and the recovery period have not been studied in re-sponse of an Olympic distance triathlon (1.5-km swim, 40-km bike, 10-km run: short-distance triathlon). The aim of this study was to evaluate the RM fatigue induced by an Olympic distance triathlon. Nine male triath-letes (24±1.1 years) underwent spirometric testing and the assessment of RM performance. Respiratory function tests were conducted in sit-ting position. Spirometric parameters, maximal inspiratory and expirato-ry pressures, and RM endurance assessed by measuring the time limit were evaluated before (pre-T), after (post-T), and the day following the triathlon (post-T-24 hr). Residual volume increased: pre-T vs. post-T (P<0.002), maximal inspiratory pressure significantly decreased from 127.4±17.2 (pre-T) to 121.6±18.5 cmH2O (post-T) (P<0.001) and returned to the pre-T value 24 hr after the race (125.0±18.6). RM endurance sig-nificantly decreased from 4:51±0:8 (pre-T) to 3:13±0:7 min (post-T, P< 0.001) and then remained decreased for 24 hr after the race from 4:51± 0:8 (pre-T) to 3:39±0:4 min 24 hr after (P<0.002). Both, strength and en-durance of inspiratory muscles decrease after Olympic distance triath-lon. Furthermore, the impaired of inspiratory muscle endurance 24 hr after the race suggested a slow recovery and persistence of inspiratory muscle fatigue.

АНАЛИЗ ИЗНОСА КОЛЕСНЫХ ПАР ВАГОНОВ УЛАН-БАТОРСКОЙ ЖЕЛЕЗНОЙ ДОРОГИ

The article is devoted to the analysis of the wear of the crest of the wheel pairs of freight cars of the Ulanbator Railway. Based on numerous experimental data, the factors affecting wear are investigated. According to the change in ridge thickness, the wear rate of the first wheelset over 5000 km is less than the third, and the wear of the second wheelset is less than the fourth. Subsequent 10,000 km and 30,000 km of run, this indicator changes in the opposite direction, therefore, it is necessary to change the sequence of wheelsets.

THE EFFECTS OF AN 18-WEEK TRAINING PROGRAMME ON MOVEMENT ECONOMY OF A LONG-DISTANCE RUNNER – A CASE STUDY

Study aim: The aim of the work was to determine the effects of an 18-week training programme on the economics of running at a speed corresponding to the lactate threshold of an athlete from the track-and-field section of AZS AWF (University of Physical Education) Kraków. In addition, the objective was to determine the average heart rate and speed during a 10-km during in relation to threshold values for these parameters. Materials and methods: In the study, heart rate and speed at lactate threshold were determined using the pitch test. The indirect calorimetry method was applied to assess energy expenditure of the run. The training work carried out by the study participant was subject to registration and quantitative as well as qualitative analysis. Results: Observations indicated that the implemented training programme resulted in a reduction of energy expenditure by 6.32% when running at threshold speed. During the 10-km competitive run, the studied athlete obtained an average heart rate and running speed at a level corresponding to 109% and 108% (respectively) of the threshold values for the specified parameters. Conclusions: The proposed training programme had a positive effect on running economics at threshold speed. It was shown that the average heart rate and speed obtained during the competition over a distance of 10 km exceeded the threshold values of the mentioned parameters by 9 and 8%, respectively.

Cumulative Metrics of Tendon Load and Damage Vary Discordantly with Running Speed.

Cumulative load has become a popular metric in running biomechanics research to account for potential spatiotemporal changes associated with different locomotion strategies. This study investigated how incorporating mechanical fatigue principles into Achilles tendon cumulative load measurements affected their relationship with running speed. Achilles tendon forces and strains were estimated from a dynamometry/ultrasound session followed by a motion capture session, where participants ran at three speeds. Three cumulative measures of increasing complexity were calculated using Achilles tendon force/strain: 1) cumulative load, defined as the product of the stance phase time integral of Achilles tendon force/strain and the stride count for 1 km of running; 2) cumulative damage, which accounted for the nonlinear relationship between load magnitude and fatigue life by exponentially weighting the time integral of Achilles tendon force/strain before multiplication with stride count; and (3) the probability of fatigue failure, which expanded upon the cumulative damage measure of Achilles tendon strain by fitting a probabilistic Weibull model to existing fatigue life data to account for the inherent variability that exists in the fatigue life of biological samples. Cumulative load measures significantly decreased with running speed, whereas the cumulative damage and probabilistic measures either increased or did not change significantly with running speed. The choice of cumulative metric has an important influence on the interpretation of overuse injury risk with changes in running speed. Although cumulative load metrics certainly provide meaningful information about the load experienced over a given distance, they do not account for the tissue damage incurred by such load. Cumulative load metrics should therefore be interpreted with caution when making inferences to overuse injury risk.

Skin Application of 4% Menthol Enhances Running Performance in Hot and Humid Climate.

Aerobic performance is negatively impacted by tropical climate due to impairment of thermoregulatory mechanisms. We tested the hypothesis that a torso application of a 4% menthol solution would have the same effect on a best performance 10-km run as an external use of cold water. Thirteen trained male athletes completed four outdoor 10-km runs (T=29.0±1.3°C, relative humidity 59.0±13.6%) wearing a tee-shirt soaked every 2-km either in a cold (~6°C) or warm/ambient (~28°C) solution, consisting in water or in a 4% menthol solution, (CTL, MENT-Amb, CLD and MENT-CLD). Run performances were improved from 4.8 to 6.1% in CLD (51.4±5.5 min), MENT-Amb (52.2±5.9 min) and MENT-CLD (51.4±5.1 min) conditions (vs. CTL, 55.4±8.4 min, P<0.05), without differences between these three conditions, whereas heart rate (177±13bpm), body temperature (38.7±0.6°C) and drink ingestion (356±170 g) were not modified. Thermal sensation after running was lower in MENT-CLD (vs. CTL, P<0.01) and thermal acceptability was higher in CLD and MENT-Amb (vs. CTL, P<0.05), but thermal comfort, feeling scale and rate of perceived exertion remained unchanged. The use of menthol on skin enhances aerobic performance in a tropical climate, and no differences in performance were observed between menthol and traditional percooling strategies. However, combining both menthol and traditional percooling brought no further improvements.

Agreement and reproducibility of field and laboratory tests in the prediction of running speed in a 10-km race in amateur runners

Knowing running speed, particularly by means of easy-to-apply tests and low cost, is important for the definition of the race strategy and the most appropriate training throughout the preparation period. The aim was to compare the agreement and reproducibility of critical velocity (CV), anaerobic threshold (AT), and the simulated time trial on the track for the determination of the running speed in a 10-km race in amateur runners. A cross-sectional study was conducted with 34 runners of both genders aged 42.4±11.0 years. We measured their CV, assessed their body composition and AT. Participants performed also a simulated time trial on a 10-km running track and an official 10-km race. The delta of the comparisons and the standard error of estimate between the running velocities determined by the CV, AT, and the simulated time trial on the track ranged from 0.55 to -0.79 km/h and 0.14 to 0.59 km/h, respectively. Furthermore, CV and AT were compared to the 10-km running speed. Good agreement and reproducibility were observed between the velocities determined by the CV, AT, and the simulated time trial on the track with the real-time of a 10-km official race.

Critical velocity estimates running velocity in a 10-km running race in recreational runners

Abstract The aim of this study was to compare the estimated running velocity in a critical velocity (CV) test with the real running velocity in a 10-km race. This is a cross-sectional study with a convenience sample of 34 runners, 20 males and 14 females (42,4 ± 11,0). The participants attended two days of testing and one day to participate in an official 10-km race. During the visits, the following tests were performed: i) 400-meter running track test and ii) 2000 meter running track test. They were randomly selected and held in official athletics track with at least 48 hours rest between them. The athletes were instructed to participate in the study properly recovered, fed and hydrated. The CV was calculated as the linear relation between distance and race time, corresponding to the slope of the linear regression line. Both tests occurred in similar climatic situations. We found good agreement between the velocities estimated through the CV test and the real running velocity of a 10-km race. Although there was a difference in velocities estimated by the CV test and the real 10-km race, the variation delta was low. Thus, these data indicate that the CV test seems to be a good tool for estimating the velocity of a 10-km race. The CV determined in the field with two fixed distances 400 and 2000 meter was valid to estimate the running velocity of a 10-km race.

Cold-Water Immersion Does Not Accelerate Performance Recovery After 10-km Street Run: Randomized Controlled Clinical Trial

ABSTRACTThe use of strategies to assure better post-effort recovery is frequent in sports settings. There are several interventions available for exercise induced muscle damage recovery, but cold-water immersion (CWI) stands out among them. The effects of CWI are unclear in the literature and, although the number of street runners has been growing, there is a gap in the scientific evidence regarding the use of CWI to recover runners’ performance after a 10-km street run. Purpose: The goal of our study was to analyze the effects of CWI on the recovery of muscle damage markers after a 10-km street run. Method: We randomly assigned thirty male recreational street runners, immediately after a 10-km street run, into three recovery groups: control (rest for 10 minutes), immersion (10 min immersed in water without ice at room temperature) and CWI (10 min immersed in water with ice at 10ºC). We assessed pain, triple hop distance, extensor peak torque and blood creatine kinase levels pre- and post-run, post-intervention and 24 hours after the run. Results: The 10-km run was enough to decrease triple hop distance and extensor peak torque, and increase levels of creatine kinase (p < 0.05); however, we found no time/group interactions in any of the assessed variables after we applied the appropriate interventions (p > 0.05). Conclusion: 10-min CWI at 10°C was no more effective than water immersion and rest in recovering muscle damage markers after 10-km runs.

Correlating clinical assessment and MRI findings in diagnosing calf injuries in elite male Australian rules footballers.

Calf complex injuries represent a significant injury burden among Australian Rules athletes. To date, there has been limited research correlating clinical and radiological findings of pathology within the calf. The objective of this study is to determine how accurately magnetic resonance imaging (MRI) findings correlate with clinical measures of calf muscle complex pathology in elite male athletes. A prospective cohort study was conducted on Australian rules elite athletes. A cohort of 45 athletes underwent a high-load training session of approximately 10 km of running. Athletes were then assessed by a sports physiotherapist who made a diagnosis of no pathology, delayed onset muscle soreness, strain or other. Subsequently, the athletes underwent MRI of their bilateral calf complexes. Radiologists interpreted the MRI findings and radiological diagnosis were correlated with clinical diagnosis. A total of 90 calf MRIs were performed. Correlation of clinical and radiological diagnosis occurred in 57 cases. Of the 33 cases which did not correlate, there were 4 radiologically significant acute calf strains in clinically asymptomatic athletes, 3 of which involved old scar tissue. MRI may detect clinically insignificant injuries within the calf complex. If an athlete does not have any clinically relevant symptoms, abnormal signal on MRI may represent a different diagnosis to muscle strain. Signal change on MRI proximal to scar tissue may represent reactive oedema. Clinical history and examination should be correlated with radiological findings is recommended when diagnosing calf injury in elite athletes.