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Papers by Lorenzo Bortolan

Journal of Biomechanics, 2022

Although it has already been demonstrated that Nordic walking has some peculiar biomechanical fea... more Although it has already been demonstrated that Nordic walking has some peculiar biomechanical features with respect to walking, the effects on balance and trunk coordination are still unknown. Our aim here was to compare margins of stability, hip stabilizer muscle activation and scapular-pelvis coordination (mean and variability of continuous relative phase) between walking and two different pole walking techniques (observational design). Eleven Nordic walking instructors were asked to walk at 5.5 km·h-1 on a flat treadmill while 1) walking, 2) Nordic walking and 3) pole walking with just elbow flexion-extension motion allowed and constrained shoulder motion (elbow technique). The 3D movements of limbs and poles were measured by an optoelectronic motion capture system, and gluteus medius activation was measured through surface electromyography. Both techniques using poles show larger mediolateral margins of stability and similar anterior-posterior margins of stability in comparison with walking (p < 0.001). The larger mediolateral margin of stability using poles (conditions 2 and 3) is accompanied by greater trunk coordination stability (greater continuous relative phase variability) than walking. Although the Nordic walking (condition 2) technique results in a similar range of scapular and pelvis transverse rotation, the general pattern of scapular-pelvis coordination was temporally delayed by approximately 20% of the gait cycle in relation to other conditions (1 and 3). In conclusion, Nordic walking provides enhanced mediolateral support and coordination stability of trunk compared with walking, suggesting that it could be proposed as a safer exercise modality than walking.

Journal of Thermal Biology, 2021

PURPOSE To investigate the effects of a very short-term acclimation protocol (VSTAP) on performan... more PURPOSE To investigate the effects of a very short-term acclimation protocol (VSTAP) on performance, physiological and perceptual responses to exercise in the heat. METHODS 12 trained male cyclists (age 31.2 ± 7; weight 71.3 ± 7 kg, VO2max: 58.4 ± 3.7 mL/kg/min) randomly performed two Time to Exhaustion Tests (TTE) at 75% of normothermic peak power output (PPO), one in normothermia (N,18°C-50% RH) and one in the heat (H,35°C-50% RH), before and after a VSTAP intervention, consisting of 3 days-90 min exercise (10min at 30% of PPO+80 min at 50% of PPO) in H (≈4.5h of heat exposure). Performance time of TTEs and physiological and perceptual variables of both TTEs and training sessions (T1, T2 and T3) were evaluated. RESULTS Magnitude Based Inferences (MBI) revealed 92/6/1% and 62/27/11% chances of positive/trivial/negative effects of VSTAP of improving performance in H (+17%) and in N (+9%), respectively. Heart Rate (HR) decreased from T1 to T3 (p < 0.001) and T2 to T3 (p < 0.001), whereas Tympanic Temperature (TyT) decreased from T1 to T2 (p = 0.047) and from T1 to T3 (p = 0.007). Furthermore, despite the increased tolerance to target Power Output (PO) throughout training sessions, RPE decreased from T1 to T3 (p = 0.032). CONCLUSIONS The VSTAP determined meaningful physiological (i.e. decreased HR and TyT) and perceptual (i.e. decreased RPE) adaptations to submaximal exercise. Furthermore, showing good chances to improve performance in the heat, it represents a valid acclimation strategy to be implemented when no longer acclimation period is possible. Finally, no cross-over effect of the VSTAP on performance in temperate conditions was detected.

Inclusion of work done by segments could become very informative in comparing XCS techniques char... more Inclusion of work done by segments could become very informative in comparing XCS techniques characterized by completely different pattern of movements. The aims of this study were to assess contribution of Wint to total mechanical work and to compare Wint between diagonal stride (DS), double poling (DP) and double poling with kick (DK

High altitude medicine & biology, 2021

[no abstract available

Metabolic power depends on mean force applied to the ground during a cycle , on rate of force app... more Metabolic power depends on mean force applied to the ground during a cycle , on rate of force application and on cost of force generation. This cost is constant at different speeds and describe the amount of energy spent to perform a Newton of muscular force In a sport where energy consumption, muscular capabilities and force application strategies can influence performance capabilities, the computation of cost of force generation could be a good index of performance ability

The three main techniques in classical cross country skiing, double poling (DP) double poling wit... more The three main techniques in classical cross country skiing, double poling (DP) double poling with kick (DK) and diagonal stride (DS), are characterized by different coordination patterns and by a different involvement of arms and legs. The aim of this study was to compare the cost of locomotion between these techniques on flat and uphill conditions

skiing / Barbara Pellegrini, Lorenzo Bortolan, Hans-Christer Holmberg, Paola Zamparo, Chiara Zopp... more skiing / Barbara Pellegrini, Lorenzo Bortolan, Hans-Christer Holmberg, Paola Zamparo, Chiara Zoppirolli, Federico Schena // Human movement science. – 2013. – № 32 (6). – P. 1415-1429. 4. Contribution of the legs to double-poling performance in elite cross-country skiers / Holmberg H.C., Lindinger S., Stoggl T., Bjorklund G., Muller E. // Med Sci Sports Exerc. – 2006. – Oct. – № 38 (10). – P. 1853-1860. 5. The international ski competition rules (icr). Book II Cross-country [Электронный ресурс] // URL: http://ussa.org/sites/default/files/documents/athletics/nordic/2013-14/documents/icr-cross-country-2013_clean.pdf. – Дата обращения 30.06.2014.

Cross country skiing is characterized by many techniques which differ in contribution offered by ... more Cross country skiing is characterized by many techniques which differ in contribution offered by upper and lower limbs to propulsion. In diagonal stride technique upper and lower body are fully involved in the movement. The aim of this study is to analyze upper body contribution in diagonal stride and the effect of training on specific power expression in elite cross country skiers

High Altitude Medicine & Biology, 2020

Scandinavian Journal of Medicine & Science in Sports, 2017

Journal of Sport and Health Science, 2020

Sport Sciences for Health, 2017

European journal of applied physiology, Jan 26, 2018

This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic ... more This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET). Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices. Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HR (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3...

Scandinavian Journal of Medicine & Science in Sports, 2016

European Journal of Applied Physiology, 2017

Sport Sciences for Health, 2016