The effects of a high intensity training on cardiovascular and muscle strength in chronic stroke patients

Introduzione. L’ictus cerebrale rappresenta la prima causa di morte e disabilità. La fitness cardiovascolare (VO2peak) nell’ictus è ridotta del 50% rispetto a soggetti sani. Studi recenti hanno dimostrato i benefici dell’allenamento in tale popolazione. Obiettivi dello studio. Il primo obiettivo dello studio è di analizzare gli effetti di un allenamento ad alta intensità (treadmill o rinforzo muscolare massimale ) nel migliorare le capacità deambulatorie, la forza muscolare, la qualità della vita e la fitness cardiovascolare. Il secondo obiettivo è di indagare le modificazioni circolatorie periferiche all’arto inferiore a seguito di tale tipologia di allenamento. Il terzo obiettivo è di confrontare le due tipologie di allenamento. Materiali e metodi. Soggetti affetti da ictus cerebrale in fase cronica sono stati arruolatati e rispettivamente sottoposti ad un allenamento ad alta intensità della forza o rinforzo muscolare massimale. Nella fase di arruolamento i soggetti sono stati screnati attraverso ECG a riposo e sottosforzo. Prima dell’inizio dell’allenamento e alla fine, i soggetti sono stati sottoposti a test clinici (6MWT, 10MWT, SF-36, SIS) e strumentali (Gait analysis, V02peak, Cw, Peripheral Factors). Risultati. Quindici soggetti sono stati arruolati nello studio. A seguito dell’allenamento ad alta intensità su treadmill, i soggetti hanno riportato miglioramenti significativi nella resistenza (p=0.012), e velocità del cammino (p=0.042), parametri spazio-temporale del cammino (stride length p=0.011, step length paretic side p=0.012, cadence p=0.037 and symmetry ratio p=0.012),, fitness cardiovascolare (relative VO2peak p=0.025, absolute VO2peak p=0.025) e costo del cammino (100% of self-selected speed (p=0.018)). Inoltre, si sono riscontrate modificazioni circolatorie periferiche soprattutto all’arto inferiore plegico (non-paretic lower limb HBO p=0.012, paretic lower limb HBO p=0.018 and HB p=0.017). I soggetti sottoposti ad un rinforzo muscolare massimale, hanno riportato miglioramenti significativi nella forza in entrambi gli arti inferiori (non-paretic lower limb isometric extension p=0.018 and flexion p=0.018, paretic lower limb isometric extension p=0.018 and flexion p=0.034). L’allenamento ad alta intensità su treadmill risulta essere maggiormente efficace rispetto all’allenamento rinforzo muscolare massimale nel migliorare le capacità deambulatorie, la fitness cardiovascolare e il costo del cammino. Conclusioni. L’allenamento ad alta intensità su treadmill migliora le capacità deambulatorie, la fitness cardiovascolare e riduce il costo del cammino. Inoltre, tale allenamento porta a modificazioni circolatorie periferiche soprattutto all’arto inferiore plegico.

Introduction. Stroke is a major cause of death and long-term disability across the globe. Physical fitness is impaired after stroke. Cardiorespiratory fitness (VO2peak) is roughly 50% of that in healthy people of the same age and sex. Previous studies have demonstrated the trainability of stroke survivors and documented beneficial physiological, psychological, sensorimotor, strength, endurance, and functional effects of various types of exercises. Aims of the study. The first aim of this project was to investigate the effects of a high intensitive physical training (high intensity treadmill training and maximal strength training) in improving gait ability, muscle strength, quality of life and cardiorespiratory fitness in cerebral stroke subjects in chronic phase. The second aim was to understand the mechanism of peripheral circulatory adaptations on lower limb muscles after high intensitive physical training. The third was to compare the effects of two type of training in such population. Material and Methods. Subjects suffered from cerebral stroke in chronic phase were enrolled in this study and respectively allocated in the high intensity treadmill training group and maximal strength training group. Subjects performed 3-month training, 3 times per week (Monday-Wednesday-Friday). The subject were screened by a medical assessment consisting of resting electrocardiography (ECG) and rest ECG pre-training and post training. Subjects were evaluated by mean clinical (6MWT, 10MWT, SF-36, SIS) and instrumental test (Gait analysis, V02peak, Cw, Peripheral Factors). Results. Fifteen subjects were enrolled in the study. Three months of high intensity treadmill training increased gait resistance (p=0.012), gait speed (p=0.042), spatio-temporal gait analysis (stride length p=0.011, step length paretic side p=0.012, cadence p=0.037 and symmetry ratio p=0.012), enhanced VO2peak (relative VO2peak p=0.025, absolute VO2peak p=0.025) and reduced cost of walking at 100% of self-selected speed (p=0.018). Furthermore, peripheral circulation adaptations were funded, in particular in paretic lower limb muscle (non-paretic lower limb HBO p=0.012, paretic lower limb HBO p=0.018 and HB p=0.017). On the other hand, patient underwent maximal strength training increased lower-limb strength (non-paretic lower limb isometric extension p=0.018 and flexion p=0.018, paretic lower limb isometric extension p=0.018 and flexion p=0.034) with no improvements in gait ability and cardiorespiratory fitness. High intensity treadmill training resulted more effective than maximal strength training in improving gait ability and cardiorespiratory fitness and reducing cost of walking. Conclusion. High intensity treadmill training improves gait ability, enhanced VO2peak and reduced cost of walking. Furthermore, peripheral circulation adaptations were funded, in particular in paretic lower limb muscle. Subjects underwent maximal strength training improved muscle strength in both lower limbs’ muscles, with no increased in gait ability and aerobic capacity.