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Volker Scheer, Tanja I. Janssen, Solveig Vieluf and Hans-Christian Heitkamp

Trail running is a popular sport that has recently been recognized by the International Association of the Athletics Federations as a new running discipline hosting its own trail world championships ( www.itra.org ). It is therefore of interest to athletes, coaches, and researchers to find training

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James W. Navalta, Jeffrey Montes, Nathaniel G. Bodell, Charli D. Aguilar, Ana Lujan, Gabriela Guzman, Brandi K. Kam, Jacob W. Manning and Mark DeBeliso

population is utilizing wearable technology. Among the most common leisure activities is hiking, which has seen participation increase almost 200 fold in recent years, and is one of the top two outdoor activities performed ( Cordell et al., 2005 ; Manning et al., 2015 ). Additionally, trail running has seen

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Nicola Giovanelli, Lea Biasutti, Desy Salvadego, Hailu Kinfu Alemayehu, Bruno Grassi and Stefano Lazzer

Purpose:

to evaluate the effects of a trail-running race on muscle oxidative function by measuring pulmonary gas exchange variables and muscle fractional O2 extraction.

Methods:

Eighteen athletes were evaluated before (PRE) and after (POST) a trail running competition of 32-km or 50-km with 2000 m or 3500 m of elevation gain, respectively. During the week before the race, runners performed an incremental uphill running test and an incremental exercise by utilizing a one-leg knee-extension (KE) ergometer. The KE exercise was repeated after the end of the race. During the KE test we measured oxygen uptake (V’O2) and micromolar changes in deoxygenated hemoglobin (Hb)+myoglobin (Mb) concentrations (Δ[deoxy(Hb+Mb)]) on vastus lateralis with a portable near-infrared spectroscopy.

Results:

V’O2peak was lower at POST vs. PRE (-23.9±9.0%, p<0.001). V’O2peak at POST was lower than V’O2 at the same workload at PRE (-8.4±15.6%, p<0.050). Peak power output and time to exhaustion decreased at POST by -23.7±14.3% and -18.3±11.3%, respectively (p<0.005). At POST the increase of Δ[deoxy(Hb + Mb)] as a function of work rate, from unloaded to peak, was less pronounced (from 20.2±10.1 to 64.5±21.1% of limb ischemia at PRE to 16.9±12.7 to 44.0±18.9% at POST). Peak Δ[deoxy(Hb+Mb)] values were lower at POST (by -31.2±20.5%; p<0.001).

Conclusions:

trail running leads to impairment in skeletal muscle oxidative metabolism, possibly related to muscle damage from repeated eccentric contractions. In association with other mechanisms, the impairment of skeletal muscle oxidative metabolism is likely responsible of the reduced exercise capacity and tolerance during and following these races.

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Roberta Antonini Philippe, Nadège Rochat, Michaël Vauthier and Denis Hauw

We analyzed the courses of experience of 10 runners who volunteered to describe their experiences of withdrawal during an ultra-trail race. Data collected contained traces of past activities elicited in self-confrontation interviews. Data were coded and compared with identify structures in common sequences. Seven representative sequences were identified: feeling pain; putting meaning to those feelings; adjusting one’s running style; attempting to overcome the problem; other runners’ influences; assessing the situation; and deciding to withdraw. Results showed that disruptive events could cause progressive, cumulative, and varied transformations in runners’ courses of experience that led inevitably to withdrawal. Practical implications for mental preparation and race management are proposed.

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Gianluca Vernillo, Alfredo Brighenti, Eloisa Limonta, Pietro Trabucchi, Davide Malatesta, Grégoire P. Millet and Federico Schena

Purpose:

To quantify changes in skeletal-muscle oxygenation and pulmonary O2 uptake (V̇O2) after an extreme ultratrail running bout.

Methods:

Before (PRE) and after (POST) the race (330-km, 24000 D±), profiles of vastus lateralis muscle oxygenation (ie, oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb], and tissue oxygenation index [TOI]) and V̇O2 were determined in 14 athletes (EXP) and 12 control adults (CON) during two 4-min constant-load cycling bouts at power outputs of 1 (p1) and 1.5 (p1.5) W/kg performed in randomized order.

Results:

At POST, normalized [HHb] values increased (p1, +38.0%; p1.5, +27.9%; P < .05), while normalized [O2Hb] (p1, –20.4%; p1.5, –14.4%; P < .05) and TOI (p1, –17.0%; p1.5, –17.7%; P < .05) decreased in EXP. V̇O2 values were similar (P > 0.05). An “overshoot“ in normalized [HHb]:V̇O2 was observed, although the increase was significant only during p1.5 (+58.7%, P = .003). No difference in the aforementioned variables was noted in CON (P > .05).

Conclusions:

The concentric and, particularly, the eccentric loads characterizing this extreme ultratrail-running bout may have led to variations in muscle structure and function, increasing the local muscle deoxygenation profile and the imbalance between O2 delivery to working muscles and muscle O2 consumption. This highlights the importance of incorporating graded training, particularly downhill bouts, to reduce the negative influence of concentric and severe eccentric loads to the microcirculatory function and to enhance the ability of runners to sustain such loading.

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Carol A. Parise and Martin D. Hoffman

Background:

Even pacing has been recommended for optimal performances in running distances up to 100 km. Trail ultramarathons traverse varied terrain, which does not allow for even pacing.

Purpose:

This study examined differences in how runners of various abilities paced their efforts in the Western States Endurance Run (WSER), a 161 km trail ultramarathon in North America, under hot vs cooler temperatures.

Method:

Temperatures in 2006 (hot) and 2007 (cooler) ranged from 7-38°C and 2-30°C, respectively. Arrival times at 13 checkpoints were recorded for 50 runners who finished the race in both years. After stratification into three groups based on finish time in 2007 (<22, 22-24, 24-30 h), paired t tests were used to compare the difference in pace across checkpoints between the years within each group. The χ2 test was used to compare differences between the groups on the number of segments run slower in the hot vs cooler years.

Results:

For all groups, mean pace across the entire 161 km race was slower in 2006 than in 2007 (9:23 ± 1:13 min/km vs 8:42 ± 1:15 min/km, P < .001) and the pace was slower from the start of the race when temperatures were still relatively cool. Overall, the <22 h cohort ran slower in 2006 than 2007 over 12 of the 14 segments examined, the 22–24 h cohort was slower across 10 of the segments, and the >24 h cohort was slower across only 6 of the segments χ2 2 = 6.00, P = .050). Comparable pacing between the 2 y corresponded with onset of nighttime and cooling temperatures.

Conclusions:

Extreme heat impairs all runners’ ability to perform in 161 km ultramarathons, but faster runners are at a greater disadvantage compared with slower competitors because they complete a greater proportion of the race in the hotter conditions.

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Fabrice Vercruyssen, Mathieu Gruet, Serge S. Colson, Sabine Ehrstrom and Jeanick Brisswalter

Background:

Physiological mechanisms behind the use of compression garments (CGs) during off-road running are unknown.

Purpose:

To investigate the influence of wearing CGs vs conventional running clothing (CON) on muscle contractile function and running economy before and after short-distance trail running.

Methods:

Knee-extensor neuromuscular function and running economy assessed from two 5-min treadmill runs (11 and 14 km/h) were evaluated before and after an 18.6-km short-distance trail run in 12 trained athletes wearing either CGs (stocking + short-tight) or CON. Quadriceps neuromuscular function was assessed from mechanical and EMG recording after maximal percutaneous electrical femoral-nerve stimulations (single-twitch doublets at 10 [Db10] and 100 Hz [Db100] delivered at rest and during maximal quadriceps voluntary contraction [MVC]).

Results:

Running economy (in mL O2 · km–1 · kg–1) increased after trail running independent of the clothing condition and treadmill speeds (P < .001). Similarly, MVC decreased after CON and CGs conditions (–11% and –13%, respectively, P < .001). For both clothing conditions, a significant decrease in quadriceps voluntary activation, Db10, Db100, and the low-to-high frequency doublet ratio were observed after trail running (time effect, all P < .01), without any changes in rectus femoris maximal M-wave.

Conclusions:

Wearing CGs does not reduce physiological alterations induced during short-distance trail running. Further studies should determine whether higher intensity of compression pressure during exercises of longer duration may be effective to induce any physiological benefits in experienced trail runners.

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Veera Ehrlén

This case study examines contemporary recreational sports practitioners’ communication practices and social tie formation from the perspective of two lifestyle sports disciplines: climbing and trail running. Online survey results from 301 climbers and trail runners from Finland indicate that computer-mediated communication (CMC) has established its place in recreational lifestyle sports cultures; however, it has not done it at the expense of face-to-face (FtF) communication. Online interaction produces weak social ties with instrumental and informative value, but physical location is essential in establishing ties with emotional and appraisal value. This paper argues that it is the sports subculture and individual practitioners’ needs that define how interaction is realized, and what importance different online and off-line communication practices have. Besides studying communication practices, this case study explores the social meanings practitioners attribute to their social contacts.

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Dennis-Peter Born, Thomas Stöggl, Mikael Swarén and Glenn Björklund

Purpose:

To investigate the cardiorespiratory and metabolic response of trail running and evaluate whether heart rate (HR) adequately reflects the exercise intensity or if the tissue-saturation index (TSI) could provide a more accurate measure during running in hilly terrain.

Methods:

Seventeen competitive runners (4 women, V̇O2max, 55 ± 6 mL · kg–1 · min–1; 13 men, V̇O2max, 68 ± 6 mL · kg–1 · min–1) performed a time trial on an off-road trail course. The course was made up of 2 laps covering a total distance of 7 km and included 6 steep uphill and downhill sections with an elevation gain of 486 m. All runners were equipped with a portable breath-by-breath gas analyzer, HR belt, global positioning system receiver, and near-infrared spectroscopy (NIRS) device to measure the TSI.

Results:

During the trail run, the exercise intensity in the uphill and downhill sections was 94% ± 2% and 91% ± 3% of maximal heart rate, respectively, and 84% ± 8% and 68% ± 7% of V̇O2max, respectively. The oxygen uptake (V̇O2) increased in the uphill sections and decreased in the downhill sections (P < .01). Although HR was unaffected by the altering slope conditions, the TSI was inversely correlated to the changes in V̇O2 (r = –.70, P < .05).

Conclusions:

HR was unaffected by the continuously changing exercise intensity; however, TSI reflected the alternations in V̇O2. Recently used exclusively for scientific purposes, this NIRS-based variable may offer a more accurate alternative than HR to monitor running intensity in the future, especially for training and competition in hilly terrain.

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Martin D. Hoffman

Purpose:

To examine pacing among the most successful runners in the 161-km Western States Endurance Run (WSER) to determine if variations in segmental speed relate to performance, ambient temperature, and calendar year.

Methods:

Segmental speed and coefficient of variation (CV) in speed were analyzed for 10 race segments of 24 races from 1985 through 2013.

Results:

Segmental speeds did not differ between the eventual winners and lead runners and only differed between the 1st and 2nd finishers in the 2nd half of the race. Mean CV in speed was lower (P < .01) for the winners (12%) than for the other top-5 finishers (14–15%). CV in speed was related (r = .80, P = .006) to finish time for the fastest 10 finish times at the WSER. Multiple linearregression analysis revealed mean CV in speed for the top-5 runners to be related to maximum ambient temperature (coefficient =.14, P < .05) and calendar year (coefficient = –.086, P = .034).

Conclusions:

Mountain trail running is characterized by wide variations in speed, but the fastest times are achieved when speed fluctuations are limited. This is generally accomplished by the winners remaining relatively close behind the lead runners before taking the lead in the middle half of the race, and then avoiding slowing as much as the other top runners in the latter race stages. Variations in speed increase with high ambient temperatures, and the small decrease in segmental speed variability among top runners across the nearly 30 y of this study suggests that the best runners have improved at pacing this race.