Testing the performance of an innovative markerless technique for quantitative and qualitative gait analysis

Gait abnormalities such as high stride and step frequency/cadence (SF-stride/second, CAD-step/second), stride variability (SV) and low harmony may increase the risk of injuries and be a sentinel of medical conditions. This research aims to present a new markerless video-based technology for quantitative and qualitative gait analysis. 86 healthy individuals (mead age 32 years) performed a 90 s test on treadmill at self-selected walking speed. We measured SF and CAD by a photoelectric sensors system; then, we calculated average \ub1 standard deviation (SD) and within-subject coefficient of variation (CV) of SF as an index of SV. We also recorded a 60 fps video of the patient. With a custom-designed web-based video analysis software, we performed a spectral analysis of the brightness over time for each pixel of the image, that reinstituted the frequency contents of the videos. The two main frequency contents (F1 and F2) from this analysis should reflect the forcing/dominant variables, i.e., SF and CAD. Then, a harmony index (HI) was calculated, that should reflect the proportion of the pixels of the image that move consistently with F1 or its supraharmonics. The higher the HI value, the less variable the gait. The correspondence SF-F1 and CAD-F2 was evaluated with both paired t-Test and correlation and the relationship between SV and HI with correlation. SF and CAD were not significantly different from and highly correlated with F1 (0.893 \ub1 0.080 Hz vs. 0.895 \ub1 0.084 Hz, p < 0.001, r2 = 0.99) and F2 (1.787 \ub1 0.163 Hz vs. 1.791 \ub1 0.165 Hz, p < 0.001, r2 = 0.97). The SV was 1.84% \ub1 0.66% and it was significantly and moderately correlated with HI (0.082 \ub1 0.028, p < 0.001, r2 = 0.13). The innovative video-based technique of global, markerless gait analysis proposed in our study accurately identifies the main frequency contents and the variability of gait in healthy individuals, thus providing a time-efficient, low-cost means to quantitatively and qualitatively study human locomotion

V’O2 kinetics in response to High-Intensity-Interval Training (HIT) and isoinertial resistance training (IRT) in older, healthy men

High intensity exercise training (HIT) accelerates V’O2 kinetics (VO2k) in older subjects. It is controversial whether IRT may elicit the same adaptation. We explored the effect of HIT and IRT on VO2k and muscle deoxygenation during moderate intensity exercise in older, healthy men. 12 men (68 yy ± 4) were exposed to 8 weeks (3 times a week) of: i) HIT, and, after 4 months, ii) IRT performed with an isoinertial YoYo. Before and after training we measured: i) V’O2 peak (V’O2p); ii) breath-by-breath V’O2 and fractional muscle O2 extraction (∆HHb) of vastus lateralis by quantitative NIRS during step-exercise transitions of moderate intensity. VO2k was modeled by means of a double - exponential function to obtain the time constant (Tau) of its primary component. The normalized ∆HHb to ∆V’O2 ratio (∆HHb/∆V’O2) was calculated as and index of the matching between muscular O2 delivery (VO2m) and uptake (QaO2). V’O2p increased after HIT (29.9 mL min-1 kg-1 ± 4.3 - 32.6 mL min-1 kg-1± 6.0, p<0.05); it was not affected by IRT. Tau decreased after HIT (26.97 s ± 5.54 - 19.63 s ± 4.31, p<0.05); it did not change after IRT. Peak ∆HHb/∆V’O2 was smaller after HIT (1.83 ± 0.63 - 1.23 ± 0.37, p<0.05); it was not affected by IRT. 8 weeks of HIT accelerated V’O2k and improved the matching between QaO2 and VO2m. IRT did not lead to any improvement of ∆HHb/∆V’O2 and left V’O2k unchanged. Results suggest that the acceleration of V’O2k was mainly due to the improved matching of VO2m to QaO2

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 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

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

Gokyo Khumbu/Ama Dablam Trek 2012

In the expedition Gokyo Khumbu/Ama Dablam Trek 2012, we studied the effects of two 12-day training periods performed both at sea level and at high altitude. The main results on adult women have been published in six original articles. In women, high altitude trekking induced CD69 T cell activation and promoted anti-stress effects of the immune responses and the oxidative balance (1). Low-to-moderate exercise training at s.l. improves the regenerative capacity of skeletal muscle and depicted the epigenetic signature of satellite cells. The cell differentiation was favored by increased [Ca2+]i and fusion index (2). On the contrary, the training in hypobaric-hypoxia induced oxidative stress and impaired the regenerative capacity of satellite cells (6). Although training did not significantly modify muscle phenotype , it induced beneficial adaptations of the oxygen transport-utilization systems witnessed by faster VO2 kinetics at exercise onset (3). The two training periods did not influence the postural stability (4). In young adult women, micturition physiological parameters were affected during adaptation to hypoxia; the correlation with SpO2 strongly suggests a role of hypoxia in these changes (5

Handcycling: training effects of a specific dose of upper body endurance training in females

Purpose: This study aims to evaluate a handcycling training protocol based on ACSM guidelines in a well-controlled laboratory setting. Training responses of a specific dose of handcycling training were quantified in a homogeneous female subject population to obtain a more in depth understanding of physiological mechanisms underlying adaptations in upper body training. Methods: 22 female able-bodied participants were randomly divided in a training (T) and control group (C). T received 7-weeks of handcycling training, 3 × 30 min/week at 65 % heart rate reserve (HRR). An incremental handcycling test was used to determine local, exercise-specific adaptations. An incremental cycling test was performed to determine non-exercise-specific central/cardiovascular adaptations. Peak oxygen uptake (peakVO2), heart rate (peakHR) and power output (peakPO) were compared between T and C before and after training. Results: T completed the training sessions at 65 ± 3 % HRR, at increasing power output (59.4 ± 8.2 to 69.5 ± 8.9 W) over the training program. T improved on handcycling peakVO2 (+18.1 %), peakPO (+31.9 %), and peakHR (+4.0 %). No improvements were found in cycling parameters. Conclusion: Handcycling training led to local, exercise-specific improvements in upper body parameters. Results could provide input for the design of effective evidence-based training programs specifically aimed at upper body endurance exercise in females

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection