Uphill Racewalking at Iso-Efficiency Speed

Abstract Padulo, J, Annino, G, Tihanyi, J, Calcagno, G, Vando, S, Smith, L, Vernillo, G, La Torre, A, and D'Ottavio, S. Uphill racewalking at iso-efficiency speed. J Strength Cond Res 27(7): 1964–1973, 2013—The aim of this study was to investigate the effects of gradients (0, 2, and 7%) on biomechanical parameters during racewalking (RW) at iso-efficiency speed (IES). During the experiment, 12 high-level athletes performed at IES on different slopes. The parameters studied were surface muscular activity (EMG) of 5 muscles of the leg using Muscle Lab (Boscosystem); kinematic parameters were collected using a high-speed camera (210 Hz) analyzed with Dartfish 5.5Pro; and heart rate (HR) was monitored with a Cardio Polar. The results showed step length (SL), step frequency (SF), and internal work (WINT) decreased with increased treadmill gradient: SL = ([0–2% = 3.48%, p = 0.158], [0–7% = 12.17%, p < 0.001]); SF = ([0–2% = 2.38%, p = 0.173], [0–7% = 6.07%, p < 0.01]); WINT = ([0–2% = 8.34%, p < 0.001], [0–7% = 22.81%, p < 0.0001]). Conversely, contact time (CT) and HR increased less significantly with the increased gradients: CT = ([0–2% = 2.46%, p = 0.198], [0–7% = 6.56%, p < 0.01]); HR = ([0–2% = 0.62%, p = 0.652], [0–7% = 3.25%, p < 0.05]). The knee angle (KE) increased, whereas ankle angle (AK) and hip angle (HP) decreased with the increased gradients: AK = ([0–2% = 1.69%, p < 0.001], [0–7% = 1.13%, p < 0.01]); HP = ([0–2% = 0.22%, p < 0.03], [0–7% = 0.16%, p = 0.456]); KE = ([0–2% = 1.01%, p < 0.001], [0–7% = 1.60%, p < 0.001]). Electromyography (EMG) significantly decreased with the increased gradients in the: tibialis anterior ([0–2% = 22.49%, p < 0.0001], [0–7% = 41.18%, p < 0.0001]) and rectus femoris ([0–2% = 15.35%, p < 0.0001], [0–7% = 29.13%, p< 0.0001]). In contrast, EMG activity was significantly increased in the vastus lateralis ([0–2% = 22.95%, p < 0.0001], [0–7% = 31.15%, p < 0.0001]), gastrocnemius medialis ([0–2% = 21.40%, p < 0.001], [0–7% = 48.37%, p < 0.0001]), and biceps femoris ([0–2% = 190.78%, p < 0.0001], [0–7% = 201.37%, p < 0.0001]). The results indicate that increasing the gradient to 2% did not elicit an increased HR in racewalkers; however, at a 7% gradient, greater muscle activity was required.

[1]  E. Coyle,et al.  Physiologic Comparison of Competitive Racewalking and Running , 1984, International journal of sports medicine.

[2]  B. R. Umberger,et al.  Stance and swing phase costs in human walking , 2010, Journal of The Royal Society Interface.

[3]  M. Udo,et al.  Physiological determinants of race walking performance in female race walkers. , 1989, British journal of sports medicine.

[4]  R. Kram,et al.  Energy cost and muscular activity required for leg swing during walking. , 2005, Journal of applied physiology.

[5]  J. Donelan,et al.  Mechanics and energetics of swinging the human leg , 2005, Journal of Experimental Biology.

[6]  G A Cavagna,et al.  Mechanics of competition walking. , 1981, The Journal of physiology.

[7]  Footstep Analysis at Different Slopes and Speeds in Elite Race Walking , 2013, Journal of strength and conditioning research.

[8]  S R Simon,et al.  A biomechanical analysis of racewalking gait. , 1986, Medicine and science in sports and exercise.

[10]  J. Tihanyi,et al.  Kinematics of Running at Different Slopes and Speeds , 2012, Journal of strength and conditioning research.

[11]  D. Brunt,et al.  Principles underlying the organization of movement initiation from quiet stance. , 1999, Gait & posture.

[12]  J. Tihanyi,et al.  A dynamometer for evaluation of dynamic muscle work , 2004, European Journal of Applied Physiology and Occupational Physiology.

[13]  G M Earhart,et al.  Form switching during human locomotion: traversing wedges in a single step. , 2000, Journal of neurophysiology.

[14]  J. Tihanyi,et al.  Uphill Running at Iso-Efficiency Speed , 2012, International Journal of Sports Medicine.

[15]  Masao Udo,et al.  Specificity of physiological adaptation to endurance training in distance runners and competitive walkers , 2004, European Journal of Applied Physiology and Occupational Physiology.

[16]  P. D. di Prampero,et al.  The Energy Cost of Human Locomotion on Land and in Water* , 1986, International journal of sports medicine.

[17]  S. D'ottavio,et al.  Kinematic Analysis of Soccer Players in Shuttle Running , 2012, International Journal of Sports Medicine.

[18]  A. Ruina,et al.  Multiple walking speed-frequency relations are predicted by constrained optimization. , 2001, Journal of theoretical biology.

[19]  M. Piacentini,et al.  Exercise Intensity and Pacing Strategy of a 5-km Indoor Race Walk During a World Record Attempt: A Case Study , 2011, Journal of strength and conditioning research.

[20]  Alain Belli,et al.  A simple device for kinematic measurements of human movement , 1992 .

[21]  K. R. Williams,et al.  The effect of stride length variation on oxygen uptake during distance running. , 1982, Medicine and science in sports and exercise.

[22]  J. F. Yang,et al.  Backward walking: a simple reversal of forward walking? , 1989, Journal of motor behavior.

[23]  Physiological characteristics of the preferred transition speed in racewalkers. , 2009, Medicine and science in sports and exercise.

[24]  A. Minetti,et al.  Measured and predicted mechanical internal work in human locomotion. , 2011, Human movement science.

[25]  G. Cavagna,et al.  The sources of external work in level walking and running. , 1976, The Journal of physiology.

[26]  A. Minetti,et al.  Mechanical determinants of the minimum energy cost of gradient running in humans. , 1994, The Journal of experimental biology.

[27]  D. B. Dill.  OXYGEN USED IN HORIZONTAL AND GRADE WALKING AND RUNNING ON THE TREADMILL. , 1965, Journal of applied physiology.

[28]  M. Murray,et al.  Kinematic and electromyographic patterns of Olympic race walkers , 1983, The American journal of sports medicine.

[29]  L G Pugh,et al.  The relation of oxygen intake and velocity of walking and running, in competition walkers , 1968, The Journal of physiology.

[30]  A. Thorstensson,et al.  Adaptations to changing speed in human locomotion: speed of transition between walking and running. , 1987, Acta physiologica Scandinavica.

[31]  M. Piacentini,et al.  An Observational Study on the Perceptive and Physiological Variables During a 10,000-m Race Walking Competition , 2012, Journal of strength and conditioning research.

[32]  A. Kuo.  A simple model of bipedal walking predicts the preferred speed-step length relationship. , 2001, Journal of biomechanical engineering.

[33]  E. Coyle,et al.  Physiological determinants of endurance performance as studied in competitive racewalkers. , 1983, Medicine and science in sports and exercise.

[34]  K. Häkkinen,et al.  Acute changes in muscle activation and leg extension performance after different running exercises in elite long distance runners , 2006, European Journal of Applied Physiology.

[35]  W G Hopkins,et al.  Quantification of Training in Competitive Sports , 1991, Sports medicine.

[36]  A. Minetti,et al.  Energy cost of walking and running at extreme uphill and downhill slopes. , 2002, Journal of applied physiology.

[37]  C. Bosco,et al.  Potentiation of myoelectrical activity of human muscles in vertical jumps. , 1982, Electromyography and clinical neurophysiology.

[38]  P. Högberg.  How do stride length and stride frequency influence the energy-output during running? , 2004, Arbeitsphysiologie.