Traditional vs non-motorized curve treadmill: differences in energetic requirements

Previous studies suggest that exercise performed on curve surface treadmill (CT) can increase energy expenditure more than exercise performed on a traditional motorized treadmill (MT). However, to date, there are no data about energy cost that confirm this hypothesis. Thus, the purpose of the study is to analyze the physiological requirements of walking and running on a CT as compared to a traditional MT. 26 subjects (11M + 15W) (24.1±3.4yy; 64.7±11.2kg; 171.1±8.6cm) performed preferred walking speed test and running ramp test to exhaustion on both treadmill in two separated sessions. The gross energy cost of walking (Cw) is greater (p<.05) in CT than in MT (3.79±0.35 j/m/kg, 2.43±0.38 j/m/kg, respectively). The gross energy cost of running (Cr) is greater (p<.05) in CT than in MT (5.05±1.67 j/m/kg, 4.09±0.70 j/m/kg, respectively). Moreover, MT allows to reach higher speeds than CT (MT:15.5±1.7 km/h, CT:13.9±1.4 km/h, p<.05) with lower peak blood lactate concentrations (MT: 8.98±2.43 mmol/L, CT: 10.75±2.76 mmol/L, p<.05). Our data confirm that i) the Cw, matched for speed, is greater in CT than MT; ii) the Cr, analyzed during incremental ramp test, is greater in CT than MT; iii) during the ramp test, for the same metabolic load, the mechanical load is lower in the CT compared to MT. The increased physical effort is due to the greater frictional characteristics and force generation requirements inherent with the use of a CT

Benefits of 8 weeks of High Intensity Training in healthy women: the Trion project

Aim High-intensity training (HIT) has recently been shown to be a suitable alternative time-saving strategy to improve athletic performance, cardiovascular fitness and muscle metabolism1. Nevertheless, women have rarely participated in studies investigating the efficacy of HIT2. Therefore, the aim of this study was to evaluate in moderately active women the effectiveness of an HIT intervention performed on a new device called Trion. Methods Before and after 8 weeks of HIT (3 time/week, 7reps x 30sec all-out interspersed with 2 min of active rest), in 35 healthy women volunteers (22.5±3.7 yy; BMI: 21.2±2.6), we measured maximal oxygen uptake (V’O2max), ventilatory threshold (VT), anaerobic performance, muscle structure, body composition, hematochemical (CHOLtot) and blood pressure profile at rest. The HIT workout was performed running on non-motorized curve treadmill and cycling on an competition bike mounted on an electromagnetic roller. Results Absolute and relative V’O2max significantly increased by 10% (p<.05); maximal power and power@VT increased by 7.2% and 6.3 % (p<.05), respectively; peak anaerobic performance significantly increased by 10% (p<.05). Large significant differences (p<.05) were identified for vastus lateralis thickness and pennation angle, +4.9% and +10.1%, respectively. Fat mass and CHOLtot decreased by 3.9% and 5.7% (p<.05), respectively. Conclusions Our results confirm the feasibility and effectiveness of HIT to improve exercise performance and health related parameters: HIT performed on Trion device was absolutely safe and well tolerated by the subjects. As confirmed in previous studies, our findings shows that exercise intensity, rather than duration, is the key factor in determining functional benefits. References 1Weston M, Effects of Low-Volume High-Intensity-Interval-Training (HIT) on Fitness in Adults: A Meta-Analysis of Controlled and Non-Controlled Trials Sports Med. 2014; 44(7): 1005–1017. 2Batacan, RB Jr. Effects of high-intensity-interval-training on cardiometabolic health: a systematic review and meta-analysis of intervention studies. Br J Sports Med. 2017 Mar;51(6):494-503

Effects of nicotine on microvascular responsiveness after nicotine satiety versus overnight nicotine abstinence

[no abstract available

EFFECT OF HIGH INTENSITY TRAINING AND ISOINERTIAL TRAINING ON MUSCLE FUNCTIONS IN OLDER ADULTS

Introduction Maximal muscle strength is a strong predictor of functional skills and ability to maintain independent living in elderly. Muscle contraction properties has been shown to decline to a greater extent than muscle strength with aging and it has been considered the main responsible of the observed decline in functional status (Izquierdo et al., 1999). Endurance high intensity interval training (HIT), by involving large muscle groups, and eccentric strength exercise (IRT), by producing high mechanical loads, could be used in elderly to improve muscle function and quality of life (Milanovi et al., 2015). Therefore, the aim of this study was to examine the changes in muscle properties in elderly after 8 wk of HIT and IRT. Methods 12 moderately active older adults (age: 69.4±4.3 yy; BMI: 22.9±2.7 kg/m2; V’O2max: 29.5±4.1 mL/kg/min) have completed 8 wk of: i) HIT, 7 two-minute cycling repetitions at 90% of V’O2max, 3 times/wk, and, after 4 months, ii) IRT performed with an isoinertial leg press (YoYo TechnologyAB) comprised 4×7 maximal concentric-eccentric knee extensions, 3 times/wk. Maximum voluntary contraction (MVC) was measured using a cell load in a custom-made setup (90° knee flexion). Electrically evoked muscle single twitch was superimposed onto MVC: neuromuscular activation (NA) was calculated as the ratio between the amplitudes of the superimposed and resting twitches. Muscle volume of the quadriceps (Qvol) was obtained by MRI scans. Results MVC at 90° knee flexion, increase significantly only after IRT (P < 0.01). Both training modalities affected significantly NA (P < 0.05): +12.4% after HIT and +14.2 after IRT. Similarly, Qvol increase by 5.1% (P < 0.05) after HIT intervention and by 4.9% (P < 0.05) after IRT. Discussion Our results confirm the feasibility and effectiveness of HIT and IRT to improve muscle qualities: 8 wk of specific training are able to modify muscle mass, MVC and neuromuscular activation in elderly subjects. This stresses the importance of using effective approaches such as exercise treatment with high loads and high intensities in the prevention of disuse in elderly individuals who are concurrently exposed to the deleterious effects of aging on muscle contractile function and mass (Behrens et al., 2016). We can therefore speculate that the two proposed training modalities may be helpful in improving functional status and prevent frailty in elderly subjects. References Izquierdo M, Aguado X, Gonzalez R, Lopez JL, Hakkinen K. (1999). Eur J Appl Physiol Occup Physiol, 79, 260-7. Milanovi Z, Sporiš G, Weston M. (2015). Sports Med, 45(10), 1469-81. Behrens M, Brown N, Bollinger R, Bubeck D, Mau-Moeller A, Weippert M, Zschorlich V, Bruhn S, Alt W. (2016). Appl Physiol Nutr Metab, 41(1), 110-3

SPEEDING OF V’O2 KINETICS IN RESPONSE TO HIGH-INTENSITY-INTERVAL TRAINING IN OLDER, HEALTHY MEN

Introduction Experimental evidence suggests that High Intensity Interval Training (HIT, high intensity - low volume exercise) may be effective in accelerating the dynamic response pulmonary O2 uptake (V’O2) in older subjects through an improvement of the matching between local O2 delivery and uptake (Williams et al., 2013). This study explores the effect of HIT on V’O2 kinetics and muscle deoxygenating during step transitions of moderate intensity, cycling exercise in older, healthy men. Methods 12 moderately active older adults (68-yy ± 4) were exposed to 8 weeks of HIT training with 7 two-minute repetitions at 40 and 90% of V ̇O2max, 3 times a week. Before and after training we measured: i) V’O2 peak (V’O2p), gas exchange threshold (GET) and respiratory compensation point (RCP) during an incremental test up to exhaustion; ii) breath-by-breath V’O2 and change of fractional muscle O2 extraction (ΔHHb) of vastus lateralis by quantitative NIRS during three step-exercise transitions performed at a workload corresponding to 90% of GET. V’O2 kinetics was modeled, after synchronization and overlapping of the three series, by means of a double - exponential function so that we estimated the time constant (Tau) of the primary component of VO2 kinetics. Finally, the normalized ΔHHb to ΔV’O2 ratio was obtained as index of the matching between muscular O2 delivery and uptake (De Roia et al., 2012; Murias et al., 2011). Results V’O2max increased by 9% (29.9 mL min-1 kg-1 ±4.3 - 32.6 mL min-1 kg-1± 6.0, p<0.01, ES 0.51) after 8 weeks of HIT. RCP (respiratory compensation point, per cent of V’O2max) significantly improved by 10% (76.4 % ± 8.3 - 82.9 % ± 4.9, p<0.05, ES 0.97); Tau decreased by about 26% (26.97 s ± 5.54 - 19.63 s ± 4.31, p<0.001, ES 1.48), suggesting a substantial acceleration of V’O2 kinetics; peak value of ΔHHb to ΔV’O2 ratio was smaller after HIT (∼ 29%) (1.83 ± 0.63 - 1.23 ± 0.37, p<0.01, ES 1.17). Discussion This study shows that 8 weeks of HIT were sufficient to induce a significant acceleration of V’O2 kinetics during moderate intensity exercise and to improve the matching between muscular O2 delivery and uptake in older, healthy men. These results suggest that the acceleration of the dynamic response of aerobic metabolism was due to an improved matching of O2 utilization to microvascular delivery. References Williams AM, Paterson DH, Kowalchuk JM. (2013) J Appl Physiol 114, 1550–1562. De Roia G, Pogliaghi S, Adami A, Papadopoulou C, Capelli C. (2012) Am J Physiol Regul Integr Comp Physiol. 302, R1158- R1166. Murias JM, Spencer MD, DeLorey DS, Gurd BJ, Kowalchuk JM, Paterson DH. (2011) J Appl Physiol 111, 1410–1415

EFFECT OF HIGH INTENSITY TRAINING AND ISOINERTIAL TRAINING ON INTERMUSCULAR ADIPOSE TISSUE IN OLDER ADULTS

Introduction Recent findings suggest that, in elderly, Intermuscular Adipose Tissue (IMAT) may be associated with inactivity and that exercise training may be able to mitigate the content of IMAT (Murphy et al., 2012; Santanasto et al., 2011). The purpose was to determine how IMAT can be influenced by exercise and if a greater reduction in IMAT occurs with concurrent aerobic High Intensity Training (HIT) and Isoinertial Resistance Training (IRT). Methods 12 moderately active older adults (age: 69.4±4.3 yy; weight: 78.5±10.5 kg; height: 171.2±5.3 cm; BMI: 22.9±2.7 kg/m2; V'O2max: 29.5±4.1 mL/kg/min) were exposed to 8 weeks of: i) HIT training with 7 two-minute cycling repetitions at 90% of V'O2max, 3 times/week and, after 4 months, ii) IRT performed with an isoinertial leg press (YoYo Technology AB) comprised 4×7 maximal concentric-eccentric knee extensions, 3 times/week. MRI of the mid-thigh was examined to determine changes in muscle composition (Cross Sectional Area (CSA) and IMAT) after exercise intervention using SliceOmatic image analysis software (Rossi et al., 2010). IMAT was defined as adipose tissue area visible between quadriceps muscle groups. Results Quadriceps CSA increased significantly after HIT and after IRT by 6% (P<0.05) and 7% (P<0.05) respectively. IMAT decreased after HIT and IRT by 31% (P<0.05) and 41% (P<0.05) respectively. Net thigh lean mass increased significantly after both training by 10% (P<0.05). Discussion Our data, in contrast with Jacobs (2014) and Goodpaster (2008) but in agreement with other previous studies (Murphy et al., 2012; Santanasto et al., 2011), show that IMAT decrease after a 8 weeks exercise intervention in older adults both after HIT and IRT. Preliminary data show that exercise training performed at high intensity in older adults may contrast skeletal muscle fat infiltration. Our study is non-randomized, not-counterbalanced and limited by small sample size: additional studies are needed to determine the most effective exercise (type, intensity, modalities) able to decrease IMAT and how this decrease may positively affect health in elderly

LIFESTYLE ASSESSMENT AND IMPROVEMENT WITH FOCUS ON LEISURE TIME PHYSICAL ACTIVITY AMONG UNIVERSITY STUDENTS: THE #STUDIOXLAVITA PROJECT

INTRODUCTION: Sedentariness, smoking, alcohol abuse and unbalanced feeding are harmful for health, leading to chronic diseases and increasing mortality rate. For young adults, University is a new social and cultural context: parents’ imprinting could be easily altered, new lifestyles take shape and personal choices emerge. Intervention programmes to advance awareness on harmful lifestyle and promote healthy habits are essential. The #studioxlavita project, launched in 2016 by the University of Brescia with these purposes, investigated students’ lifestyle, with special emphasis on physical activity . METHODS: We developed two consecutive facultative surveys, of 15 <1st level> and 52 items <2nd level>, addressed to all the University’s students. Questions were about leisure time physical activity , use of fitness technology, relationship with friends, classmates and parents, feed, physical appearance, body self-perception, physical and mental health, use of certain substances or products , night-time rest and beliefs concerning healthy behaviours. In the 2nd level survey we also adopted the Kessler Psychological Distress Scale and the short form of the International Physical Activity Questionnaire to estimate the amount of PA carried out in the last 7 days. Students who filled in both questionnaires received a personal report including the aggregate data analysis, a comparison with other investigations and indications about healthy habits, according to recommendations and guidelines. RESULTS: 3,436 out of 15,688 students filled in the1st level survey. Of them, 778 accepted to participate in the 2nd level survey, and 456 completed it. 1st level survey revealed that 72% of the students practised LTPA <45% regularly and 27% occasionally>. LTPA is largely performed <44% of the student> in non-competitive form, with recreational and/or health purposes. According to IPAQ-SF categorical score, 24%, 34% and 42% of the students performed low, moderate and high levels of PA, respectively. In 2st level survey, 76% of the students wished to practise more PA; 42% would participate in practical sport courses. CONCLUSION: University is an ideal setting for promoting lifestyle change among a captive audience. Intervention programs to increment PA are acclaimed by students. The students from University of Brescia reported higher LTPA practice than the national average people between 18 and 34 years <47%, data from Italian National Institute of Statistics, 2015>, although this parameter was assessed with different methods

EFFECTS OF PHYSICAL ACTIVITY PROMOTION AMONG UNIVERSITY STUDENTS: THE #STUDIOXLAVITA PROJECT

INTRODUCTION: Sedentariness is a major health problem in our time and physical activity promotion is an imperative commitment for healthcare systems. Recommendations from WHO indicate a minimum of 150 minutes of moderate intensity aerobic exercise as weekly standard for adults. Strategies to increment PA practice are implemented in different settings, such as house care, school, University and workplace. The project #studioxlavita <#SXLV> was launched by the University of Brescia in 2016 with the aim of collecting data about undergraduates lifestyle and encourage healthy behaviours. In particular we focused on PA assessment and promotion in a Universitybased setting. METHODS: Two consecutive surveys were sent to all students . Q0 included the short form of the International Physical Activity Questionnaire , the Kessler Psychological Distress Scale and additional questions on several lifestyle aspects. Among responders, we selected 40 students who agreed to take part in one of the following 15-week practical sport courses: ultimate frisbee, muscle strengthening and dance fitness. Before and after being engaged in practical sport courses, students underwent cardiopulmonary exercise test and skinfold thickness measurements, in order to assess peak oxygen consumption and percent body fat . Finally, to assess possible lifestyle changes, we sent them additional surveys at the end of the practical sport courses and 30 days after . Paired t-test was used to analyse significant differences. RESULTS: 27 students <16 female, 11 male; age: 22.7±3.7> concluded sport activity courses and filled in Q1. Of them, 20 completed also Q2. Overall courses attendance was 57%. At T1 , normalized Q̇O2peak increased with respect to T0 <37.0±6.9 vs 35.2±7.4 ml/min/Kg, p=0.03>. Conversely, percent body fat decreased <16.5±6.4 vs 18.3±7.5, p=0.01>. In Q1, 20 students declared to have a more active lifestyle since the beginning of the courses. In Q2, IPAQ-SF-derived total weekly energy expenditure was higher than in Q0, although not significant <5,839 ±7,035 MET*min vs 2,770±2,457 MET*min, p=0.1>. Q2 showed a reduced K6 scale score with respect to Q0 <13.8±4.6 vs 15.8±4.9, p=0.03>. CONCLUSION: With the sport activity courses established in #SXLV we gave students the opportunity to comply with WHO recommendations. After courses, they appeared to practice more PA, have a higher maximal aerobic capacity, a lower percent body fat and a lower grade of psychological distress than before courses. Simple activities as those proposed by #SXLV are sufficient to reduce sedentariness and improve the quality of life of student