andrea loi

The muscle metaboreflex activation has been shown essential to reach normal hemodynamic response during exercise. It has been demonstrated that patients with multiple sclerosis (MS) have impaired autonomic functions and cardiovascular regulation during exercise. However, to the best of our knowledge, no previous research to date has studied the metaboreflex in MS patients. The purpose of this study was to investigate the hemodynamic response to metaboreflex activation in patients with MS (n = 43) compared to an age-matched, control group (CTL, n = 21). Cardiovascular response during the metaboreflex was evaluated using the post-exercise muscle ischemia (PEMI) method and during a control exercise recovery (CER) test. The difference in hemodynamics between the PEMI and the CER test was calculated and this procedure allowed for the assessment of the metaboreflex response. Hemodynamics was estimated by impedance cardiography. The MS group showed a normal mean blood pressure (MBP) response as compared to the CTL group (+6.5 ± 6.9 vs. +8±6.8 mmHg, respectively), but this response was achieved with an increase in systemic vascular resistance, that was higher in the MS with respect to the CTL group (+137.6 ± 300.5 vs. -14.3 ± 240 dyne·s(-1) cm(-5), respectively). This was the main consequence of the MS group's incapacity to raise the stroke volume (-0.65 ± 10.6 vs. +6.2 ± 12.8 ml, respectively). It was concluded that MS patients have an impaired capacity to increase stroke volume (SV) in response to low level metaboreflex, even if they could sustain the MBP response by vasoconstriction. This was probably a consequence of their chronic physical de-conditioning.

The purpose of this study is to quantitatively assess the effect of 6 months of supervised adapted physical activity (APA i.e. physical activity designed for people with special needs) on spatio-temporal and kinematic parameters of gait in persons with Multiple Sclerosis (pwMS). Twenty-two pwMS with Expanded Disability Status Scale scores ranging from 1.5 to 5.5 were randomly assigned either to the intervention group (APA, n = 11) or the control group (CG, n = 11). The former underwent 6 months of APA consisting of 3 weekly 60-min sessions of aerobic and strength training, while CG participants were engaged in no structured PA program. Gait patterns were analyzed before and after the training using three-dimensional gait analysis by calculating spatio-temporal parameters and concise indexes of gait kinematics (Gait Profile Score - GPS and Gait Variable Score - GVS) as well as dynamic Range of Motion (ROM) of hip, knee, and ankle joints. The training originated significant improvements in stride length, gait speed and cadence in the APA group, while GPS and GVS scores remained practically unchanged. A trend of improvement was also observed as regard the dynamic ROM of hip, knee, and ankle joints. No significant changes were observed in the CG for any of the parameters considered. The quantitative analysis of gait supplied mixed evidence about the actual impact of 6 months of APA on pwMS. Although some improvements have been observed, the substantial constancy of kinematic patterns of gait suggests that the full transferability of the administered training on the ambulation function may require more specific exercises. Implications for rehabilitation Adapted Physical Activity (APA) is effective in improving spatio-temporal parameters of gait, but not kinematics, in people with multiple sclerosis. Dynamic range of motion during gait is increased after APA. The full transferability of APA on the ambulation function may require specific exercises rather than generic lower limbs strength/flexibility training.

Required Coefficient of Friction (RCOF) is one of the most critical gait parameters associated to the occurrence of slipping in individuals affected by neurological disorders characterized by balance impairments. This study aims to calculate RCOF in people with Multiple Sclerosis (MS) on the basis of three-dimensional Gait Analysis (GA) data. This study enrolls 22 people with MS (pwMS) who were characterized by an Expanded Disability Status Score in the range 1.5-6 and 10 healthy controls (HC). All participants underwent to three-dimensional GA from which we extracted kinematic and kinetic data (i.e. the Ground Reaction Forces, GRF, and joint moments and powers in the sagittal plane). RCOF was calculated as the ratio of the shear to normal GRF components during the stance phase of gait cycle, and normalized by the walking velocity. Thus, the following variables were extracted: first peak (named P1COF), valley (named V1COF), and second peak (named P2COF) in RCOF curve; also computating the maximum ankle dorsi-plantarflexion moment (MOMmax) and the maximum ankle joint power (PWRmax). Our data revealed that P2COF results are significantly lower in pwMS when compared to HC (p=0.043; Z=-2.025). In pwMS, the study found a moderate, positive correlation between V1COF and MOMmax (r=0.558; p<0.001) and a moderate, positive correlation between EDSS score and MOMmax (rho=0.622; p=0.001). While, in HC group, the study detected a moderate positive correlation between P1COF and MOM max (r=0.636; p=0.008). Friction during mid stance and push off phases is critically important to determine whether the frictional capabilities of foot/floor interface are sufficient to prevent slips in pwMS. The impaired ankle moment in MS group causes increased P2COF in comparison to HC, increasing the risk of slipping in the critical phase of transmission of the developed forces to kinematic chain. Also, the correlation analysis among RCOF values and kinetic variables describe the interplay between V1COF and MOMmax: the higher V1COF is, the higher is MOMmax; and the different correlation the study found between COF and kinetic parameters in MS and HC group highlightes the different gait patterns of the two classes of subjects.

The purpose of the present investigation was to study the metabolic demand and cardiovascular response during a typical horse riding session. To this aim, 19 (9 male, 10 female) riders, regularly participating in competitions, were enrolled. They underwent a preliminary, incremental exercise test on a cycle-ergometer to assess their anaerobic threshold (AT) and VO2max. Then, participants underwent a riding training session, which comprised periods of walking, trotting, and cantering for a total of 20 min. Oxygen uptake (VO2), carbon dioxide production (VCO2), and heart rate (HR) were obtained throughout the preliminary and riding test by means of a portable metabolic system. Moreover, excess of CO2 production (CO2excess) and oxygen pulse (OP) were also calculated to obtain an estimate of anaerobic glycolysis and stroke volume. The main result was that all collected parameters remained below the AT level throughout the riding session, with the exception of HR that approached the AT level only during cantering. In detail, during cantering, average VO2, VCO2, HR, CO2excess, and OP values were 1289 ± 331 mL min(-1), 1326 ± 266 mL min(-1), 158 ± 22 bpm, 215 ± 119 mL min(-1), and 7.8 ± 1.6 mL/bpm, respectively. It was concluded that riding imposes only light to moderate stress on the aerobic and anaerobic energy systems. Moreover, cardiovascular reserve is only moderately recruited in terms of inotropism, while chronotropism can be stimulated more.

The muscle metaboreflex activation has been shown essential to reach normal hemodynamic response during exercise. It has been demonstrated that patients with multiple sclerosis (MS) have impaired autonomic functions and cardiovascular regulation during exercise. However, to the best of our knowledge, no previous research to date has studied the metaboreflex in MS patients. The purpose of this study was to investigate the hemodynamic response to metaboreflex activation in patients with MS (n = 43) compared to an age-matched, control group (CTL, n = 21). Cardiovascular response during the metaboreflex was evaluated using the post-exercise muscle ischemia (PEMI) method and during a control exercise recovery (CER) test. The difference in hemodynamics between the PEMI and the CER test was calculated and this procedure allowed for the assessment of the metaboreflex response. Hemodynamics was estimated by impedance cardiography. The MS group showed a normal mean blood pressure (MBP) respon...

The aim of the present investigation was to assess the role of aging on the contribution of diastolic function during metaboreflex activation. In particular, it aimed to determine whether age-related impairment in diastolic function would produce a different hemodynamic response in elderly subjects (EG) as compared to young controls (CTL). Hemodynamic response to metaboreflex activation obtained by post-exercise muscle ischemia (PEMI) was gathered in 22 EG and 20 healthy CTL. Subjects also performed a control exercise recovery (CER) test to compare data from the PEMI test. The main results showed that the EG group reached higher mean arterial blood pressure (MAP) increment than the CTL group during the PEMI test (+11.2 ± 8.6 vs 6.1 ± 6.4 mmHg in the EG and CTL group, respectively). Moreover, the mechanism by which this response was achieved was different between the two groups. In detail, EG reached the target MAP by increasing systemic vascular resistance (+235.2 ± 315.1 vs -44.4 ± 167.7 dynes s(-1) cm(-5) for the EG and the CTL group, respectively), whereas MAP response in the CTL was the result of an increase in cardiac pre-load (-1.5 ± 11.2 vs 14 ± 13.7 ml in end-diastolic volume for the EG and the CTL group, respectively), which led to a rise in stroke volume and cardiac output. Moreover, early filling peak velocities showed a higher response in the CTL than EG group. This study demonstrates that diastolic function is important for normal hemodynamic adjustment during the metaboreflex and to avoid excessive vasoconstriction.

Exercise training for subjects over 65 should be applied to improve quality of life. However, physiological adaptations are transitory and disappear after training reduction or cessation (Bousquet et all, 2013 - Mujika & Bousquet, 2010). Beside detraining exerts well known effects in young athletes, while limited information is available for elderly individuals. PURPOSE: The aim of this study was to investigate the effects of 8 weeks of detraining in elderly subjects (age > 65 yrs), after 12 weeks of exercise prescription at vigorous intensity. METHODS: 17 healthy participants (69.3 ± 4.3 yrs) performed a randomized controlled trial on training program about 12 weeks at vigorous intensity (range 64-85% of Heart Rate Reserve) followed by 8 weeks of detraining. Before and after the training cessation period, subjects underwent an exercise test on a cycle Ergometer test until exhaustion to assess VO2max. Heart Rate Recovery HRR, Waist-Hip ratio (WHR) and Body Mass Index (BMI) were a...

Considering the relation between body weight composition and energy cost of running, we tested the hypothesis that by modifying body composition by means of a combined protocol of specific diet and training, the energy cost of motion (Cr) may be reduced. Forty-five healthy and normal-weight subjects were divided into 3 groups that performed a different treatment: the first group attended a dietary protocol (D), the second group participated in a running program (R), and the third group followed both the dietary and running protocols (R&D). Each subject underwent 3 anthropometric and exercise evaluation tests during 1 year (at entry (T0), month 6 (T6), and month 12 (T12)) to assess body composition and Cr adjustments. The mean fat mass (FM) values were reduced in R&D from 12.0 ± 4.0 to 10.4 ± 3.0 kg (p < 0.05 T0 vs. T12) and in the D group from 14.2 ± 5.8 to 11.6 ± 4.7 kg (p < 0.05 T0 vs. T12). Conversely, the mean fat free mass values increased in R&D (from 56.3 ± 8.8 to 58.3 ...

This study aimed at comparing maximal oxygen uptake (VO2max), maximal heart rate (HRmax), and anaerobic threshold (AT) obtained from tethered swimming (SW) and three other testing procedures: cycling (CY), running (RU), and arm cranking (AC). Variables were assessed in 12 trained male swimmers by a portable gas analyzer connected to a modified snorkel system to allow expired gases collection during swimming. Athletes exhibited a higher VO2max during the SW test as compared to the CY and the AC tests. There was no significant difference in VO2max between the SW and the RU test, but the Bland and Altman plot highlighted a poor agreement between results. Moreover, AT occurred at higher workloads during SW in comparison to the other tests. These results do not support the use of any unspecific testing procedures to estimate VO2max, HRmax, and AT for swimming.

The beneficial effects of beetroot juice supplementation (BJS) have been tested during cycling, walking, and running. The purpose of the present study was to investigate whether BJS can also improve performance in swimmers. Fourteen moderately trained male master swimmers were recruited and underwent two incremental swimming tests randomly assigned in a pool during which workload, oxygen uptake (VO₂), carbon dioxide production (VCO₂), pulmonary ventilation (VE), and aerobic energy cost (AEC) of swimming were measured. One was a control swimming test (CSW) and the other a swimming test after six days of BJS (0.5 l/day organic beetroot juice containing about 5.5 mmol of NO₃⁻). Results show that workload at anaerobic threshold was significantly increased by BJS as compared to the CSW test (6.3 ± 1 and 6.7 ± 1.1 kg during the CSW and the BJS test respectively). Moreover, AEC was significantly reduced during the BJS test (1.9 ± 0.5 during the SW test vs. 1.7 ± 0.3 kcal·kg⁻¹1·h⁻¹ during t...