Cross-country Runners Research Articles

Running Smoothness Differs Between Trained And Untrained Individuals

A gait smoothness index has been used to identify differences in walking gait between healthy and disease populations, but has not yet been applied to running gait, where it may indicate skill differences. The index quantifies the relative level of out-of-phase harmonics in the frequency spectrum. PURPOSE: To use a cross-sectional study design to discriminate running smoothness in four groups of healthy, young subjects. METHODS: We measured 3-D trunk acceleration using optical motion capture (Vicon, Centennial, CO) at 200 Hz for 60-90 s at 3.33, 3.89, and 4.44 m·s-1. Subjects included: 1) NCAA Division I cross-country runners (n=11); 2) high school cross-country runners (n=19); 3) untrained subjects with BMI < 25 (n = 8); and 4) untrained subjects with BMI > 25 (n=8). We performed a fast Fourier transform of the mediolateral (ML), anterioposterior (AP), and vertical (VT) acceleration signal and calculated the amplitude of the first 20 harmonics. AP and VT are dominated by the second harmonic, so odd numbered harmonics (out-of-phase accelerations) detract from smoothness. The smoothness index is the ratio of the sum of the even harmonic amplitudes to the sum of the odd harmonic amplitudes. Since the first harmonic dominates ML, the smoothness index for this axis is the ratio of odd to even. A higher ratio indicates greater smoothness. We used a group×speed ANOVA to test for main effects, with a Bonferroni post hoc test where appropriate. Analyses were performed in Matlab (2013b, Mathworks, Natick, MA). RESULTS: College and high school runners had higher AP smoothness than untrained-low BMI and untrained-high BMI (6.74 and 7.54 versus 4.33 and 4.43, respectively, p<0.05). For VT, college and high school runners had higher smoothness than untrained-high BMI (10.91 and 10.26 versus 6.75, respectively, p<0.05). High school runners also had a higher VT smoothness than untrained-low BMI (10.26 versus 8.32, respectively, p<0.05). There were no speed effects or any group×speed interactions (p>0.05). CONCLUSION: Running smoothness was significantly different between trained and untrained subject groups. It is unknown if this is due to training effects on biomechanics and motor control, training-associated body composition changes, or pre-existing characteristics leading to self-selection of running, all of which might change the contribution of out-of-phase movement to the AP and VT acceleration signal.

Training Intensity Distribution in Collegiate Cross Country Runners

Training Intensity Distribution in Collegiate Cross Country Runners

The Effect of Energy Status on Distance Running Performance Across a Competitive Season in Female Cross-country Runners

Female cross-country runners are at a higher risk for chronic energy deficiency (ED). Cross-sectional evidence demonstrates the negative effects of ED on surrogate markers of performance. The association between chronic ED and distance running performance in female cross-country runners across a season is unclear. PURPOSE: To examine competitive 5km time trial performance across a season in female cross-country runners categorized by energy status. METHODS: 18 female cross-country runners (19.5 ± 0.3 yrs, 54.6 ± 1.4 kg, 61.2 ± 1.7 mL/kg/min) participated in this prospective observational study across a 10-12 week competitive season. Outcome measures were assessed pre and post-season. Resting energy expenditure (REE) was measured using indirect calorimetry and compared to the Harris Benedict predicted REE (REE/pREE) as a marker of ED. Performance was assessed during an outdoor 5km time trial. Fasting blood samples were assayed for total triiodothyronine (TT3). Repeated measures ANOVA were performed to compare log TT3 and 5km time trial outcomes across the season among participants grouped by tertiles (n=6 each group) of pre-season REE/pREE (severe ED (SED; REE/pREE<0.84), moderate ED (MED; 0.84≤REE/pREE<0.90), and energy replete (ER; REE/pREE≥0.90)). RESULTS: There was a significant group effect (p=0.004), however no time or interaction effects (p>0.49) were observed for the 5km time trial. Pre-season the SED group was 4.1s (p=0.005) slower vs the MED group, while no differences were observed between the ER and the SED or MED groups (p>0.1). Post-season the SED group was 3.7s (p=0.002) and 2.6s (p=0.023) slower vs the MED and ER groups, respectively. For log TT3 there were no significant time or group effects (p>0.15), however a trend toward a significant interaction effect (p=0.097) was observed. Pre-season log TT3 was lower (p=0.043) in the SED vs MED groups, a trend to significance (p=0.067) was observed between the SED and ER groups, with no difference between the ER and MED groups. Log TT3 was not different between groups post-season (p=0.36). CONCLUSIONS: We provide evidence of decrements in 5km time trial performance in severely ED female cross-country runners. Early detection of severe ED utilizing REE may be a strategy for preventing suboptimal distance running performance across a competitive season.

What are the Differences in Injury Proportions Between Different Populations of Runners? A Systematic Review and Meta-Analysis.

BackgroundMany runners suffer from injuries. No information on high-risk populations is available so far though.ObjectivesThe aims of this study were to systematically review injury proportions in different populations of runners and to compare injury locations between these populations.Data SourcesAn electronic search with no date restrictions was conducted up to February 2014 in the PubMed, Embase, SPORTDiscus and Web of Science databases. The search was limited to original articles written in English. The reference lists of the included articles were checked for potentially relevant studies.Study Eligibility CriteriaStudies were eligible when the proportion of running injuries was reported and the participants belonged to one or more homogeneous populations of runners that were clearly described. Study selection was conducted by two independent reviewers, and disagreements were resolved in a consensus meeting.Study Appraisal and Synthesis MethodsDetails of the study design, population of runners, sample size, injury definition, method of injury assessment, number of injuries and injury locations were extracted from the articles. The risk of bias was assessed with a scale consisting of eight items, which was specifically developed for studies focusing on musculoskeletal complaints.ResultsA total of 86 articles were included in this review. Where possible, injury proportions were pooled for each identified population of runners, using a random-effects model. Injury proportions were affected by injury definitions and durations of follow-up. Large differences between populations existed. The number of medical-attention injuries during an event was small for most populations of runners, except for ultra-marathon runners, in which the pooled estimate was 65.6 %. Time-loss injury proportions between different populations of runners ranged from 3.2 % in cross-country runners to 84.9 % in novice runners. Overall, the proportions were highest among short-distance track runners and ultra-marathon runners.LimitationsThe results were pooled by stratification of studies according to the population, injury definition and follow-up/recall period; however, heterogeneity was high.ConclusionsLarge differences in injury proportions between different populations of runners existed. Injury proportions were affected by the duration of follow-up. A U-shaped pattern between the running distance and the time-loss injury proportion seemed to exist. Future prospective studies of injury surveillance are highly recommended to take running exposure and censoring into account.Electronic supplementary materialThe online version of this article (doi:10.1007/s40279-015-0331-x) contains supplementary material, which is available to authorized users.

Muscle size, quality, and body composition: characteristics of division I cross-country runners.

The primary purpose of this study was to identify the relationship between muscle cross-sectional area (mCSA), echo intensity (EI), and body composition of Division I cross-country runners. The secondary purpose was to examine differences in these variables in athletes stratified based on stress-fracture (SFx) history. Thirty-six athletes were stratified based on sex and SFx history. A panoramic scan vastus lateralis was performed using a GE Logiq-e B-mode ultrasound. Echo intensity and mCSA were determined from the scan using a grayscale imaging software (ImageJ). Body composition measures were determined using dual-energy x-ray absorptiometry. For females, mCSA was significantly correlated with left leg lean mass (LM; R = 0.54) and EI (R = -0.57). Lean mass was significantly correlated with bone mineral density (BMD; R = 0.58) and bone mineral content (BMC; R = 0.56), whereas BMC was also correlated with leg LM (R = 0.72). For males, mCSA was significantly correlated with leg LM (R = 0.66), BMD (R = 0.50), and BMC (R = 0.54). Leg LM was significantly correlated with BMD (R = 0.53) and BMC (R = 0.77). Personal best times for males were significantly correlated with fat mass (R = 0.489) and %fat (R = 0.556) for the 10- and 5-km races, respectively. Female and male athletes with a history of SFx were not significantly different across any variables when compared with athletes with no history. These correlations suggest that more muscle mass may associate with higher BMD and BMC for stronger bone structure. Modifications in training strategies to include heavy resistance training and plyometrics may be advantageous for preventing risk factors associated with SFx reoccurrence.

Longitudinal monitoring of performance in cross-country running by young orienteering runners

The aim of this paper focused on the one of platform of the system for regular work with talented children and youth on the field of the orienteering. The article brings partial results of longitudinal testing talented youth of East Bohemian region of the Czech Republic in orienteering. 10 – 14-year orienteering talented runners took part in testing motor skills standardized tests. The text approaches the methodology and presents the selected results of the measurement – the performance in cross-country running test at 3 km and 5 km depending on age category as one of the many tests that young athletes participating always at the beginning of the season. Results of the research show a significant difference among selected athletes and indicate tendencies performance in cross-country running of youth orienteering runners in the region. The conclusions highlight the long-decreasing level of endurance abilities of young orienteering contestants between 1997 and 2014, describes the possible reasons and suggestions remedial options.

Muscle Size, Quality, and Body Composition: Characteristics of Division I Cross-Country Runners

Muscle Size, Quality, and Body Composition: Characteristics of Division I Cross-Country Runners

Prevalence of stress urinary incontinence in elite female endurance athletes.

The goal of the study was to assess the prevalence of stress urinary incontinence in a group of elite female endurance athletes, as professional sport is one of the risk factors for stress urinary incontinence. SUI rates in the groups of female cross-country skiers and runners were compared to determine whether the training weather conditions like temperature and humidity influenced the prevalence of urinary incontinence. An anonymous questionnaire was distributed among 112 elite female athletes ie., 57 cross-country skiers and 55 runners. We used a short form of the Urogenital Distress Inventory (UDI-6) to assess the presence of SUI symptoms and the level of urogenital distress. Only women who had been practicing sport professionally for at least 3 years, on an international and national level, were included in the research. The study group consisted of 76% nulliparous and 24% parous women. 45.54% of all participants reported leakage of urine associated with sneezing or coughing which indicates stress urinary incontinence. 29.46% were not bothered by the urogenital distress symptoms. 42.86% of the participants were slightly bothered by the symptoms, 18.75% were moderately bothered, 8.04% were significantly bothered and 0.89% were heavily bothered. The absence of statistically significant differences between both groups seems to indicate that training weather conditions did not influence the prevalence of SUI in elite female endurance athletes.

Anti-Dieting Advice From Teammates: A Pilot Study of the Experience of Female Collegiate Cross Country Runners

Disordered eating behaviors and restrictive dieting can have negative health consequences for female athletes. Teammates can play an important role in primary and secondary prevention of these unhealthy eating practices through verbal and non-verbal communication about what behaviors are normative and desirable. The present study tested two tested hypotheses related to the way anti-dieting advice from teammates is distributed: (a) that there are significant between-team differences in the level of anti-dieting advice received, and (b) that the frequency of anti-dieting advice from teammates is positively associated with the severity of an individual’s eating disorder symptomatology and negatively associated with their body mass index (BMI). Participants were female members (n = 89) of six U.S. National Collegiate Athletic Association Division I women’s cross country teams. Findings revealed significant between-team differences in the frequency of anti-dieting advice, controlling for team levels of disordered eating. Eating pathology and BMI were positively associated with anti-dieting advice received. Implications for the design of interventions to encourage effective within-team communication for promoting teammate health are discussed.

Single muscle fiber gene expression with run taper.

This study evaluated gene expression changes in gastrocnemius slow-twitch myosin heavy chain I (MHC I) and fast-twitch (MHC IIa) muscle fibers of collegiate cross-country runners (n = 6, 20±1 y, VO2max = 70±1 ml•kg−1•min−1) during two distinct training phases. In a controlled environment, runners performed identical 8 kilometer runs (30∶18±0∶30 min:s, 89±1% HRmax) while in heavy training (∼72 km/wk) and following a 3 wk taper. Training volume during the taper leading into peak competition was reduced ∼50% which resulted in improved race times and greater cross-section and improved function of MHC IIa fibers. Single muscle fibers were isolated from pre and 4 hour post run biopsies in heavily trained and tapered states to examine the dynamic acute exercise response of the growth-related genes Fibroblast growth factor-inducible 14 (FN14), Myostatin (MSTN), Heat shock protein 72 (HSP72), Muscle ring-finger protein-1 (MURF1), Myogenic factor 6 (MRF4), and Insulin-like growth factor 1 (IGF1) via qPCR. FN14 increased 4.3-fold in MHC IIa fibers with exercise in the tapered state (P<0.05). MSTN was suppressed with exercise in both fiber types and training states (P<0.05) while MURF1 and HSP72 responded to running in MHC IIa and I fibers, respectively, regardless of training state (P<0.05). Robust induction of FN14 (previously shown to strongly correlate with hypertrophy) and greater overall transcriptional flexibility with exercise in the tapered state provides an initial molecular basis for fast-twitch muscle fiber performance gains previously observed after taper in competitive endurance athletes.

Summer training factors and risk of musculoskeletal injury among high school cross-country runners.

Prospective cohort. To examine the relationship between summer training practices and risk of injury during the first month of a high school interscholastic cross-country season. Several prospective studies have reported a high incidence of injury in adolescent cross-country runners. However, limited reports exist on the role of summer training practices and risk of injury among these runners. Four hundred twenty-one athletes (186 girls, 235 boys) who competed in interscholastic cross-country were followed during a cross-country season. At the start of the season, all participants completed a questionnaire regarding summer training routines. Time-loss, running-related injuries were tracked during the subsequent season. Logistic regression analysis was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of initial injury during the first month of the season associated with summer training variables. Sixty-seven runners (15.9%) had a confirmed injury during the first month of the season, with a higher percent among girls (19.4%) than boys (13.2%) (P = .06). Overall, 60.1% of the participants ran during the summer prior to the season, with a significantly higher percent among girls (71.5%) than boys (51.1%) (P<.0001). Overall, no significant association (OR = 0.9; 95% CI: 0.5, 1.5; P = .90) was found between not running sometime during the preceding summer and increased risk of initial injury during the first month of the season. Among only the runners who ran during the summer, after adjusting for sex and prior injury, first-month injuries were more common among those who did not frequently alternate short and long mileage on different days (OR = 3.0; 95% CI: 1.4, 6.4; P = .005), and/or who ran 8 weeks or fewer (OR = 2.7; 95% CI: 1.2, 5.8; P = .01) during their summer training. Running 8 weeks or fewer (P = .03), not frequently alternating mileage on different days (P = .01), and running a higher percentage of time on predominantly hill (P = .001) and irregular terrains (P = .004) were associated with increased risk of injury for girls. These findings suggest that injuries during the first month of the high school cross-country season may be reduced if runners who participate in summer training activities run a greater number of weeks and frequently vary their daily running mileage during the summer. For girls, training programs that reduce mileage on hills and irregular terrains may help to minimize the occurrence of running-related injury. Prognosis, level 1b-.

Effect of Compression Stockings on Physiological Responses and Running Performance in Division III Collegiate Cross-Country Runners During a Maximal Treadmill Test

There is a growing trend for runners to use compression stockings (CS) to improve performance. The purpose of this study was to determine the effect of CS on physiological variables associated with running performance. Participants were 10 NCAA division III cross-country runners. The study used a randomized, crossover design with 2 conditions (with CS and without CS). Both conditions consisted of a maximal treadmill test that involved 3-minute stages of increasing speed and incline, separated by a minute and one-half walking recovery stage. Seven days later, the participants repeated the maximal test but switched CS condition. Heart rate, blood lactate (BLa), blood lactate threshold, maximal oxygen consumption (VO2max), respiratory exchange ratio, rating of perceived exertion, and time to fatigue were measured. Before and during the maximal treadmill tests, the variables showed no significant difference (p ≤ 0.05) between the CS conditions. Blood lactate was lower while wearing CS when measured during recovery at the 1-minute (CS = 13.3 ± 2.9 mmol · L(-1), non-CS = 14.8 ± 2.8 mmol · L(-1), p = 0.03) and the 5-minute (CS = 11.0 ± 2.7 mmol · L(-1), non-CS = 12.8 ± 2.8 mmol · L(-1), p = 0.02) periods. Time to fatigue was longer without CS (CS = 23.570 ± 2.39 minutes, non-CS = 23.93 ± 2.49 minutes, p = 0.04). These findings suggest that CS may not improve running performance, but could lend credence to certain manufacturers' claims of improved recovery through lower BLa values after exercise.

Mental toughness in sport: motivational antecedents and associations with performance and psychological health.

We argue that basic psychological needs theory (BPNT) offers impetus to the value of mental toughness as a mechanism for optimizing human functioning. We hypothesized that psychological needs satisfaction (thwarting) would be associated with higher (lower) levels of mental toughness, positive affect, and performance and lower (higher) levels of negative affect. We also expected that mental toughness would be associated with higher levels of positive affect and performance and lower levels of negative affect. Further, we predicted that coaching environments would be related to mental toughness indirectly through psychological needs and that psychological needs would indirectly relate with performance and affect through mental toughness. Adolescent cross-country runners (136 male and 85 female, M(age) = 14.36) completed questionnaires pertaining to BPNT variables, mental toughness, and affect. Race times were also collected. Our findings supported our hypotheses. We concluded that BPNT is generative in understanding some of the antecedents and consequences of mental toughness and is a novel framework useful for understanding mental toughness.

Relationship Between Stress Fractures, Muscle Size, Quality, And Body Composition In Division I Cross-country Runners

Relationship Between Stress Fractures, Muscle Size, Quality, And Body Composition In Division I Cross-country Runners

The Association Between Quality Of Movement And Dynamic Stability In High School Cross Country Runners.

The Association Between Quality Of Movement And Dynamic Stability In High School Cross Country Runners.

Changes in Achilles’ Tendon Cross-sectional Area in Collegiate Cross-country Runners Across a Competitive Season

Changes in Achilles’ Tendon Cross-sectional Area in Collegiate Cross-country Runners Across a Competitive Season

Odd-impact loading results in increased cortical area and moments of inertia in collegiate athletes

The purpose of this study was to investigate tibial changes in volumetric bone mineral density and geometry that take place in athletes from pre- to post-season. Female college athletes (n=36) and ten controls recruited from the student population were included in the study. Participants had their left tibia scanned by pQCT at 4, 20, and 66% of the overall length from the distal end before and after their competitive seasons. Subjects were divided into four groups: non-athlete (controls, n=10), moderate-impact (cross-country runners, n=13), high-impact (volleyball and basketball, n=11), and odd-impact (soccer, n=12). Anterior-posterior and medial-lateral diameter increased at the 4% site in control subjects. In the moderate-impact group, medial-lateral moment of inertia (MOI) increased by 1.2±1.8 (mean±SD) percent at the 20% site. In high-impact group, anterior-posterior MOI increased by 1.6±2.0 percent at the 66% site. In odd-impact group, cortical area (1.4±2.3%) and cortical thickness (1.8±2.8%) increased at the 20% site increased, as did the polar MOI (1.8±2.2%) at the 66% site. Load-specific changes resulting in improved measures of bone strength take place in athletes during a competitive season. These changes may result in improved resistance to fractures and stress fractures.

Team-Level Approaches to Addressing Disordered Eating: A Qualitative Study of Two Female Collegiate Cross Country Running Teams

The objective of this study was to consider strategies used by two similarly competitive female collegiate cross country running teams to address teammate eating behaviors perceived to be unhealthy and problematic. Data were obtained through semi-structured individual interviews with team members (n = 35). Teams differed in how they addressed problematic eating behaviors: members of one team described a collaborative, positive, team-focused and direct approach, while the most commonly described strategy for the other team was to do nothing. Possible contextual and compositional reasons for between-team differences and implications for prevention and detection of disordered eating among female athletes are discussed.

Osteoporosis health beliefs of women with increased risk of the female athlete triad.

Women with increased risk of the female athlete triad (Triad) are more susceptible to osteoporosis compared to other women. The study included 65 women with increased risk of the Triad who had their osteoporosis health beliefs measured to assess their concern for the disease. Participants were female collegiate cross-country runners at different levels of competition, including National Association of Intercollegiate Athletics (NAIA) and National Collegiate Athletic Association (NCAA) Divisions III, II, and I. Although these participants have an increased risk of the Triad and are more susceptible to osteoporosis, on a scale of 1 to 5, results showed that they had low to moderate perceived susceptibility to osteoporosis with a mean score as high as 2.81 and moderate perceived severity of osteoporosis with a mean score as high as 3.38. A statistically significant difference in perceived susceptibility to osteoporosis was found between female collegiate cross-country runners in the NAIA and those in the NCAA DIII. Reasons that could explain relatively low levels of concern for osteoporosis in female collegiate cross-country runners and reasons for significant differences in perceived susceptibility to osteoporosis are given, and recommendations for health education and intervention to help care for this population are provided.

Effects of Resistance Training on Running Economy and Cross-country Performance

Heavy-resistance training and plyometric training offer distinct physiological and neuromuscular adaptations that could enhance running economy and, consequently, distance-running performance. To date, no studies have examined the effect of combining the two modes of training on running economy or performance. Fifty collegiate male and female cross-country runners performed a 5-km time trial and a series of laboratory-based tests to determine aerobic, anthropometric, biomechanical, and neuromuscular characteristics. Thereafter, each athlete participated in a season of six to eight collegiate cross-country races for 13 wk. After the first 4 wk, athletes were randomly assigned to either heavy-resistance or plyometric plus heavy-resistance training. Five days after completing their final competition, runners repeated the same set of laboratory tests. We also estimated the effects of the intervention on competition performance throughout the season using athletes of other teams as controls. Heavy-resistance training produced small-moderate improvements in peak speed, running economy, and neuromuscular characteristics relative to plyometric resistance training, whereas changes in biomechanical measures favored plyometric resistance training. Men made less gains than women in most tests. Both treatments had possibly harmful effects on competition times in men (mean = 0.5%; 90% confidence interval = ±1.2%), but there may have been benefit for some individuals. Both treatments were likely beneficial for all women (-1.2%; ±1.3%), but heavy-resistance training was possibly better than plyometric resistance training. The changes in laboratory-based parameters related to distance-running performance were consistent with the changes in competition times for women but only partly for men. Our data indicate that women should include heavy-resistance training in their programs, but men should be cautious about using it in season until more research establishes whether certain men are positive or negative responders.