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Giovanelli N, Pellegrini B, Bortolan L, Mari L, Schena F, Lazzer S. Do poles really "save the legs" during uphill pole walking at different intensities? Eur J Appl Physiol 2023; 123:2803-2812. [PMID: 37392255 DOI: 10.1007/s00421-023-05254-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/10/2023] [Indexed: 07/03/2023]
Abstract
PURPOSE In sky- and trail-running competitions, many athletes use poles. The aims of this study were to investigate whether the use of poles affects the force exerted on the ground at the feet (Ffoot), cardiorespiratory variables and maximal performance during uphill walking. METHODS Fifteen male trail runners completed four testing sessions on different days. On the first two days, they performed two incremental uphill treadmill walking tests to exhaustion with (PWincr) and without poles (Wincr). On the following days, they performed submaximal and maximal tests with (PW80 and PWmax) and without (W80 and Wmax) poles on an outdoor trail course. We measured cardiorespiratory parameters, the rating of perceived exertion, the axial poling force and Ffoot. RESULTS When walking on the treadmill, we found that poles reduced maximum Ffoot (- 2.8 ± 6.4%, p = 0.03) and average Ffoot (- 2.4 ± 3.3%, p = 0.0089). However, when outdoors, we found pole effect only for average Ffoot (p = 0.0051), which was lower when walking with poles (- 2.6 ± 3.9%, p = 0.0306 during submaximal trial and - 5.21 ± 5.51%, p = 0.0096 during maximal trial). We found no effects of poles on cardiorespiratory parameters across all tested conditions. Performance was faster in PWmax than in Wmax (+ 2.5 ± 3.4%, p = 0.025). CONCLUSION The use of poles reduces the foot force both on the treadmill and outdoors at submaximal and maximal intensities. It is, therefore, reasonable to conclude that the use of poles "saves the legs" during uphill without affecting the metabolic cost.
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Affiliation(s)
- Nicola Giovanelli
- Department of Medicine, University of Udine, P.Le Kolbe 4, 33100, Udine, Italy.
- School of Sport Science, Udine, Italy.
| | - Barbara Pellegrini
- CeRiSM Research Centre "Sport, Mountain, and Health", Rovereto, TN, Italy
- Department of Engineering for Innovation Medicine, University of Verona, Verona, Italy
| | - Lorenzo Bortolan
- CeRiSM Research Centre "Sport, Mountain, and Health", Rovereto, TN, Italy
- Department of Engineering for Innovation Medicine, University of Verona, Verona, Italy
| | - Lara Mari
- Department of Medicine, University of Udine, P.Le Kolbe 4, 33100, Udine, Italy
- School of Sport Science, Udine, Italy
| | - Federico Schena
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Stefano Lazzer
- Department of Medicine, University of Udine, P.Le Kolbe 4, 33100, Udine, Italy
- School of Sport Science, Udine, Italy
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2
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Lemire M, Faricier R, Dieterlen A, Meyer F, Millet GP. Relationship between biomechanics and energy cost in graded treadmill running. Sci Rep 2023; 13:12244. [PMID: 37507405 PMCID: PMC10382573 DOI: 10.1038/s41598-023-38328-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
The objective of this study was to determine whether the relationships between energy cost of running (Cr) and running mechanics during downhill (DR), level (LR) and uphill (UR) running could be related to fitness level. Nineteen athletes performed four experimental tests on an instrumented treadmill: one maximal incremental test in LR, and three randomized running bouts at constant speed (10 km h-1) in LR, UR and DR (± 10% slope). Gas exchange, heart rate and ground reaction forces were collected during steady-state. Subjects were split into two groups using the median Cr for all participants. Contact time, duty factor, and positive external work correlated with Cr during UR (all, p < 0.05), while none of the mechanical variables correlated with Cr during LR and DR. Mechanical differences between the two groups were observed in UR only: contact time and step length were higher in the economical than in the non-economical group (both p < 0.031). This study shows that longer stance duration during UR contributes to lower energy expenditure and Cr (i.e., running economy improvement), which opens the way to optimize specific running training programs.
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Affiliation(s)
- Marcel Lemire
- Faculty of Sport Sciences, University of Strasbourg, Strasbourg, France
- Institut de Recherche en Informatique, Mathématiques, Automatique Et Signal, Université de Haute-Alsace, 68070, Mulhouse, France
| | - Robin Faricier
- School of Kinesiology, The University of Western Ontario, London, ON, Canada
| | - Alain Dieterlen
- Faculty of Sport Sciences, University of Strasbourg, Strasbourg, France
- Institut de Recherche en Informatique, Mathématiques, Automatique Et Signal, Université de Haute-Alsace, 68070, Mulhouse, France
| | - Frédéric Meyer
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
- Digital Signal Processing Group, Department of Informatics, University of Oslo, Oslo, Norway.
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
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3
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Saller M, Nagengast N, Frisch M, Fuss FK. A Review of Biomechanical and Physiological Effects of Using Poles in Sports. Bioengineering (Basel) 2023; 10:bioengineering10040497. [PMID: 37106684 PMCID: PMC10135831 DOI: 10.3390/bioengineering10040497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/31/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
The use of poles in sports, to support propulsion, is an integral and inherent component of some sports disciplines such as skiing (cross-country and roller), Nordic walking, and trail running. The aim of this review is to summarize the current state-of-the-art of literature on multiple influencing factors of poles in terms of biomechanical and physiological effects. We evaluated publications in the subfields of biomechanics, physiology, coordination, and pole properties. Plantar pressure and ground reaction forces decreased with the use of poles in all included studies. The upper body and trunk muscles were more active. The lower body muscles were either less active or no different from walking without poles. The use of poles led to a higher oxygen consumption (VO2) without increasing the level of perceived exertion (RPE). Furthermore, the heart rate (HR) tended to be higher. Longer poles reduced the VO2 and provided a longer thrust phase and greater propulsive impulse. The mass of the poles showed no major influence on VO2, RPE, or HR. Solely the activity of the biceps brachii increased with the pole mass.
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Affiliation(s)
- Maximilian Saller
- Chair of Biomechanics, Faculty of Engineering Science, University of Bayreuth, 95447 Bayreuth, Germany
| | - Niko Nagengast
- Chair of Biomechanics, Faculty of Engineering Science, University of Bayreuth, 95447 Bayreuth, Germany
| | - Michael Frisch
- Chair of Biomechanics, Faculty of Engineering Science, University of Bayreuth, 95447 Bayreuth, Germany
| | - Franz Konstantin Fuss
- Chair of Biomechanics, Faculty of Engineering Science, University of Bayreuth, 95447 Bayreuth, Germany
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4
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Fornasiero A, Savoldelli A, Zignoli A, Callovini A, Decet M, Bortolan L, Schena F, Pellegrini B. Eager to set a record in a vertical race? Test your VO 2max first! J Sports Sci 2023; 40:2544-2551. [PMID: 36725692 DOI: 10.1080/02640414.2023.2172801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We investigated the relationship between maximal oxygen consumption (VO2max) and performance in vertical races (VRs). In total, 270 performances, from 26 VRs, and cardiopulmonary data of 64 highly-trained mountain runners (53 M, V O2max: 75.7±5.8 mL/min/kg; 11 F: 65.7±3.4 mL/min/kg), collected over a 11-year period (2012-2022), were analysed. The relationship between performance and VO2max was modelled separately for national (NVRs), international (IVRs), and VRs of current pole-unassisted and pole-assisted vertical kilometre (VK) records (RVRs). Three different (p<0.001) exponential models described the relationship between performance and VO2max in IVRs (R2=0.96, p<0.001), NRs (R2=0.91, p<0.001) and RVRs (R2=0.97, p<0.001). Estimated VO2max requirements (with 95% CI) to win/set a record time in IVRs were 86.2(85.3-87.1)/89.4(88.2-90.5) and 74.0(73.6-74.4)/76.8(76.4-77.3) mL/min/kg, for males and females, respectively, 86.1(85.0-87.1)/90.4(89.0-91.8) and 74.8(74.2-75.3)/77.1(77.6-77.7) mL/min/kg in RVRs, decreasing to 83.7(82.5-84.9)/87.6(86.0-89.2) and 66.8(65.9-67.7)/70.7(70.1-71.4) mL/min/kg in NVRs. Our study also suggested a tendency towards a non-uniform variation in the metabolic demand of off-road running, likely attributable to the different features of the VRs (e.g., terrain, technical level, use of poles). These data provide mean VO2max requirements for mountain runners to win and establish new records in VRs and stimulate new research on the energy cost of off-road running.
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Affiliation(s)
- Alessandro Fornasiero
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Aldo Savoldelli
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Andrea Zignoli
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Industrial Engineering, University of Trento, Trento, Italy
| | - Alexa Callovini
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Marco Decet
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Lorenzo Bortolan
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Schena
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Barbara Pellegrini
- Department of Neurosciences, Biomedicine and Movement Sciences, CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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5
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The Energetic Costs of Uphill Locomotion in Trail Running: Physiological Consequences Due to Uphill Locomotion Pattern-A Feasibility Study. LIFE (BASEL, SWITZERLAND) 2022; 12:life12122070. [PMID: 36556435 PMCID: PMC9787284 DOI: 10.3390/life12122070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/28/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
The primary aim of our feasibility reporting was to define physiological differences in trail running (TR) athletes due to different uphill locomotion patterns, uphill running versus uphill walking. In this context, a feasibility analysis of TR athletes' cardiopulmonary exercise testing (CPET) data, which were obtained in summer 2020 at the accompanying sports medicine performance center, was performed. Fourteen TR athletes (n = 14, male = 10, female = 4, age: 36.8 ± 8.0 years) were evaluated for specific physiological demands by outdoor CPET during a short uphill TR performance. The obtained data of the participating TR athletes were compared for anthropometric data, CPET parameters, such as V˙Emaximum, V˙O2maximum, maximal breath frequency (BFmax) and peak oxygen pulse as well as energetic demands, i.e., the energy cost of running (Cr). All participating TR athletes showed excellent performance data, whereby across both different uphill locomotion strategies, significant differences were solely revealed for V˙Emaximum (p = 0.033) and time to reach mountain peak (p = 0.008). These results provide new insights and might contribute to a comprehensive understanding of cardiorespiratory consequences to short uphill locomotion strategy in TR athletes and might strengthen further scientific research in this field.
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Pole Walking Is Faster but Not Cheaper During Steep Uphill Walking. Int J Sports Physiol Perform 2022; 17:1037-1043. [PMID: 35316790 DOI: 10.1123/ijspp.2021-0274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 12/23/2021] [Accepted: 01/27/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE The aim of this study was to compare pole walking (PW) and walking without poles (W) on a steep uphill mountain path (1.3 km, 433 m of elevation gain) at 2 different intensities: a maximal effort that would simulate a vertical kilometer intensity and a lower intensity (80% of maximal) simulating an ultratrail race. METHODS On the first day, we tested the participants in the laboratory to determine their maximal physiological parameters, respiratory compensation point, and gas exchange threshold. Then, they completed 4 uphill tests along a mountain path on 4 separate days, 2 at their maximum effort (PWmax and Wmax, randomized order) and 2 at 80% of the mean vertical velocity maintained during the first 2 trials (PW80 and W80, randomized order). We collected metabolic data, heart rate, blood lactate concentration, and rating of perceived exertion at the end of each trial. We also collected rating of perceived exertion at every 100 m of elevation gain during PW80 and W80. RESULTS Participants completed the maximal effort faster with poles versus without poles (18:51 [03:12] vs 19:19 [03:01] in min:s, P = .013, d = 0.08, small). Twelve of the 15 participants (80%) improved their performance when they used poles. During PW80 and W80, none of the physiological or biomechanical parameters were different. CONCLUSION In the examined condition, athletes should use poles during steep uphill maximal efforts to obtain the best performance. Conversely, during submaximal effort, the use of poles does not provide advantages in uphill PW.
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7
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Energetics and Mechanics of Steep Treadmill Versus Overground Pole Walking: A Pilot Study. Int J Sports Physiol Perform 2022; 17:663-666. [PMID: 35008038 DOI: 10.1123/ijspp.2021-0252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/30/2021] [Accepted: 08/16/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE To compare energetics and spatiotemporal parameters of steep uphill pole walking on a treadmill and overground. METHODS First, the authors evaluated 6 male trail runners during an incremental graded test on a treadmill. Then, they performed a maximal overground test with poles and an overground test at 80% (OG80) of vertical velocity of maximal overground test with poles on an uphill mountain path (length = 1.3 km, elevation gain = 433 m). Finally, they covered the same elevation gain using poles on a customized treadmill at the average vertical velocity of the OG80. During all the tests, the authors measured oxygen uptake, carbon dioxide production, heart rate, blood lactate concentration, and rate of perceived exertion. RESULTS Treadmills required lower metabolic power (15.3 [1.9] vs 16.6 [2.0] W/kg, P = .002) and vertical cost of transport (49.6 [2.7] vs 53.7 [2.1] J/kg·m, P < .001) compared with OG80. Also, oxygen uptake was lower on a treadmill (41.7 [5.0] vs 46.2 [5.0] mL/kg·min, P = .001). Conversely, respiratory quotient was higher on TR80 compared with OG80 (0.98 [0.02] vs 0.89 [0.04], P = .032). In addition, rate of perceived exertion was higher on a treadmill and increased with elevation (P < .001). The authors did not detect any differences in other physiological measurements or in spatiotemporal parameters. CONCLUSIONS Researchers, coaches, and athletes should be aware that steep treadmill pole walking requires lower energy consumption but same heart rate and rate of perceived exertion than overground pole walking at the same average intensity.
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8
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Pellegrini B, Zoppirolli C, Stella F, Bortolan L, Holmberg HC, Schena F. Biomechanical analysis of the "running" vs. "conventional" diagonal stride uphill techniques as performed by elite cross-country skiers. JOURNAL OF SPORT AND HEALTH SCIENCE 2022; 11:30-39. [PMID: 32439501 PMCID: PMC8847964 DOI: 10.1016/j.jshs.2020.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/20/2020] [Accepted: 03/17/2020] [Indexed: 06/11/2023]
Abstract
PURPOSE This study aimed to compare biomechanical aspects of a novel "running" diagonal stride (DSRUN) with "conventional" diagonal stride (DSCONV) skiing techniques performed at high speed. METHODS Ten elite Italian male junior cross-country skiers skied on a treadmill at 10 km/h and at a 10° incline utilizing both variants of the diagonal stride technique. The 3-dimensional kinematics of the body, poles, and roller skis; the force exerted through the poles and foot plantar surfaces; and the angular motion of the leg joints were determined. RESULTS Compared to DSCONV, DSRUN demonstrated shorter cycle times (1.05 ± 0.05 s vs. 0.75 ± 0.03 s (mean ± SD), p < 0.001) due to a shorter rolling phase (0.40 ± 0.04 s vs. 0.09 ± 0.04 s, p < 0.001); greater force applied perpendicularly to the roller skis when they had stopped rolling forward (413 ± 190 N vs. 890 ± 170 N, p < 0.001), with peak force being attained earlier; prolonged knee extension, with a greater range of motion during the roller ski-stop phase (28° ± 4° vs. 16° ± 3°, p = 0.00014); and more pronounced hip and knee flexion during most of the forward leg swing. The mechanical work performed against friction during rolling was significantly less with DSRUN than with DSCONV (0.04 ± 0.01 J/m/kg vs. 0.10 ± 0.02 J/m/kg, p < 0.001). CONCLUSION Our findings demonstrate that DSRUN is characterize by more rapid propulsion, earlier leg extension, and a greater range of motion of knee joint extension than DSCONV. Further investigations, preferably on snow, should reveal whether DSRUN results in higher acceleration and/or higher peak speed.
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Affiliation(s)
- Barbara Pellegrini
- CeRiSM (Research Centre of Mountain Sport and Health), University of Verona, Rovereto 38068, Italy; Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona 37129, Italy.
| | - Chiara Zoppirolli
- CeRiSM (Research Centre of Mountain Sport and Health), University of Verona, Rovereto 38068, Italy; Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona 37129, Italy
| | - Federico Stella
- CeRiSM (Research Centre of Mountain Sport and Health), University of Verona, Rovereto 38068, Italy
| | - Lorenzo Bortolan
- CeRiSM (Research Centre of Mountain Sport and Health), University of Verona, Rovereto 38068, Italy; Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona 37129, Italy
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund 83125, Sweden; School of Kinesiology, University of British Columbia, Vancouver BC V6T 1Z1, Canada; Biomechanics Laboratory, Beijing Sport University, Beijing 100084, China
| | - Federico Schena
- CeRiSM (Research Centre of Mountain Sport and Health), University of Verona, Rovereto 38068, Italy; Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona 37129, Italy
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9
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Bortolan L, Savoldelli A, Pellegrini B, Modena R, Sacchi M, Holmberg HC, Supej M. Ski Mountaineering: Perspectives on a Novel Sport to Be Introduced at the 2026 Winter Olympic Games. Front Physiol 2021; 12:737249. [PMID: 34744777 PMCID: PMC8566874 DOI: 10.3389/fphys.2021.737249] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/20/2021] [Indexed: 11/13/2022] Open
Abstract
Ski mountaineering is a rapidly growing winter sport that involves alternately climbing and descending slopes and various racing formats that differ in length and total vertical gain, as well as their distribution of downhill and uphill sections. In recent years, both participation in and media coverage of this sport have increased dramatically, contributing, at least in part, to its inclusion in the 2026 Winter Olympics in Milano-Cortina. Here, our aim has been to briefly describe the major characteristics of ski mountaineering, its physiological and biomechanical demands, equipment, and training/testing, as well as to provide some future perspectives. Despite its popularity, research on this discipline is scarce, but some general characteristics are already emerging. Pronounced aerobic capacity is an important requirement for success, as demonstrated by positive correlations between racing time and maximal oxygen uptake and oxygen uptake at the second ventilatory threshold. Moreover, due to the considerable mechanical work against gravity on demanding uphill terrain, the combined weight of the athlete and equipment is inversely correlated with performance, prompting the development of both lighter and better equipment in recent decades. In ski mountaineering, velocity uphill is achieved primarily by more frequent (rather than longer) strides due primarily to high resistive forces. The use of wearable technologies, designed specifically for analysis in the field (including at elevated altitudes and cold temperatures) and more extensive collaboration between researchers, industrial actors, and coaches/athletes, could further improve the development of this sport.
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Affiliation(s)
- Lorenzo Bortolan
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | - Aldo Savoldelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | - Barbara Pellegrini
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | - Roberto Modena
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | | | | | - Matej Supej
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
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10
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Whiting CS, Allen SP, Brill JW, Kram R. Steep (30°) uphill walking vs. running: COM movements, stride kinematics, and leg muscle excitations. Eur J Appl Physiol 2020; 120:2147-2157. [PMID: 32705391 DOI: 10.1007/s00421-020-04437-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/10/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE We sought to biomechanically distinguish steep uphill running from steep uphill walking and explore why athletes alternate between walking and running on steep inclines. METHODS We quantified vertical center of mass (COM) accelerations and basic stride parameters for both walking and running at a treadmill speed of 1.0 m/s on the level and up a 30° incline. We also investigated how electromyography (EMG) of the gluteus maximus (GMAX), vastus medialis (VM), medial gastrocnemius (MG), and soleus (SOL) muscles differ between gaits when ascending steep hills. RESULTS The vertical COM accelerations for steep uphill walking exhibited two peaks per step of magnitude 1.47 ± 0.23 g and 0.79 ± 0.10 g. In contrast, steep running exhibited a single peak per step pattern with a magnitude of 1.81 ± 0.15 g. Steep uphill running exhibited no aerial phase, 40% faster stride frequency, and 40% shorter foot-ground contact time compared to steep uphill walking but similar leg swing times. SOL showed 36% less iEMG per stride during steep uphill running versus steep uphill walking, but all other EMG comparisons between steep running and walking were not significantly different. CONCLUSIONS Multiple biomechanical variables clearly indicate that steep uphill running is a distinctly different gait from steep uphill walking and is more similar to level running. The competing desires to minimize the energetic cost of locomotion and to avoid exhaustion of the SOL may be a possible explanation for gait alternation on steep inclines.
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Affiliation(s)
- Clarissa S Whiting
- Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO, 80309-0354, USA
| | - Stephen P Allen
- Applied Biomechanics Lab, Department of Integrative Physiology, University of Colorado, Boulder, CO, 80309-0354, USA
| | - Jackson W Brill
- Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO, 80309-0354, USA
| | - Rodger Kram
- Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO, 80309-0354, USA.
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