Erreka Gil-Rey

Hip-worn triaxial accelerometers are widely used to assess physical activity in terms of energy expenditure. Methods for classification in terms of different types of activity of relevance to the skeleton in populations at risk of osteoporosis are not currently available. This publication aims to assess the accuracy of four machine learning models on binary (standing and walking) and tertiary (standing, walking, and jogging) classification tasks in postmenopausal women. Eighty women performed a shuttle test on an indoor track, of which thirty performed the same test on an indoor treadmill. The raw accelerometer data were pre-processed, converted into eighteen different features and then combined into nine unique feature sets. The four machine learning models were evaluated using three different validation methods. Using the leave-one-out validation method, the highest average accuracy for the binary classification model, 99.61%, was produced by a k-NN Manhattan classifier using a basic statistical feature set. For the tertiary classification model, the highest average accuracy, 94.04%, was produced by a k-NN Manhattan classifier using a feature set that included all 18 features. The methods and classifiers within this study can be applied to accelerometer data to more accurately characterize weight-bearing activity which are important to skeletal health.

Background: Despite the established benefits of regular exercise for patients with cancer to counteract the deleterious effects of the disease itself and treatment-related adverse effects, most of them do not engage in sufficient levels of physical activity and there is a paucity of data on the integration of efficacious exercise programs that are accessible and generalizable to a large proportion of patients with cancer into routine cancer care. Objective: We intend to examine the effects attributable to the implementation of a community-based exercise program on cardiorespiratory functional capacity and quality of life for patients with cancer. Methods: This will be a hybrid study. In the first experimental phase, patients diagnosed with any type of cancer will be randomized into two parallel groups. One group immediately performs Bizi Orain, a 3-month supervised exercise program (3 times a week), in addition to behavioral counseling in a primary health care setting; the other is a reference group that starts the exercise program 3 months later (delayed treatment). In the second observational phase, the entire cohort of participants will be followed-up for 5 years. Any person diagnosed with cancer in the previous 2 years is eligible for the program. The program evaluation involves the uptake, safety, adherence, and effectiveness assessed after completion of the program and with follow-ups at 3, 6, 12, 24, 36, 48, and 60 months. The primary outcomes of the experimental study, to be compared between groups, are improved physical function and quality of life, whereas overall survival is the main objective of the prospective study. To analyze the association between changes in physical activity levels and overall survival, longitudinal mixed-effects models will be used for repeated follow-up measures. Results: A total of 265 patients have been enrolled into the study since January 2019, with 42 patients from the hematology service and 223 from the oncology service. Conclusions: Bizi Orain is the first population-based exercise program in Spain that will offer more insight into the implementation of feasible, generalizable, and sustainable supportive care services involving structured exercise to extend survival of patients with cancer, improve their physical function and quality of life, and reverse the adverse effects of their disease and related treatments, thereby reducing the clinical burden. Trial Registration: ClinicalTrials.gov NCT03819595; http://clinicaltrials.gov/ct2/show/NCT03819595 International Registered Report Identifier (IRRID): DERR1-10.2196/24835

How exercise intensity targets, calibrated according to oxygen consumption, relate to vertical impacts during weight-bearing exercise is currently unknown. The authors investigated the relationship between vertical peaks (VPs) and metabolic equivalents (METs) of oxygen consumption in 82 women during walking and running. The magnitude of VPs, measured using a hip-worn triaxial accelerometer, was derived from recommended aerobic exercise intensity targets. VPs were 0.63 ± 0.18g at the lower recommended absolute exercise intensity target (3 METs) but >1.5g at the upper end of moderate-intensity activities (1.90 ± 1.13g at 6 METs). Multilevel linear regression analyses identified speed and type of locomotion as the strongest independent predictors of VPs, explaining 54% and 11% of variance, respectively. The authors conclude that, in contrast to lower intensities, exercising close to or above the 6-MET threshold generates VPs of osteogenic potential, suggesting this could provide simultaneous benefits to decrease all-cause mortality and osteoporosis risk.

BACKGROUND Despite the established benefits of regular exercise for patients with cancer to counteract the deleterious effects of the disease itself and treatment-related adverse effects, most of them do not engage in sufficient levels of physical activity and there is a paucity of data on the integration of efficacious exercise programs that are accessible and generalizable to a large proportion of patients with cancer into routine cancer care. OBJECTIVE We intend to examine the effects attributable to the implementation of a community-based exercise program on cardiorespiratory functional capacity and quality of life for patients with cancer. METHODS This will be a hybrid study. In the first experimental phase, patients diagnosed with any type of cancer will be randomized into two parallel groups. One group immediately performs Bizi Orain, a 3-month supervised exercise program (3 times a week), in addition to behavioral counseling in a primary health care setting; the other is a reference group that starts the exercise program 3 months later (delayed treatment). In the second observational phase, the entire cohort of participants will be followed-up for 5 years. Any person diagnosed with cancer in the previous 2 years is eligible for the program. The program evaluation involves the uptake, safety, adherence, and effectiveness assessed after completion of the program and with follow-ups at 3, 6, 12, 24, 36, 48, and 60 months. The primary outcomes of the experimental study, to be compared between groups, are improved physical function and quality of life, whereas overall survival is the main objective of the prospective study. To analyze the association between changes in physical activity levels and overall survival, longitudinal mixed-effects models will be used for repeated follow-up measures. RESULTS A total of 265 patients have been enrolled into the study since January 2019, with 42 patients from the hematology service and 223 from the oncology service. CONCLUSIONS Bizi Orain is the first population-based exercise program in Spain that will offer more insight into the implementation of feasible, generalizable, and sustainable supportive care services involving structured exercise to extend survival of patients with cancer, improve their physical function and quality of life, and reverse the adverse effects of their disease and related treatments, thereby reducing the clinical burden. CLINICALTRIAL ClinicalTrials.gov NCT03819595; http://clinicaltrials.gov/ct2/show/NCT03819595 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/24835

This study aimed to estimate the maximal lactate steady-state velocity (_vMLSS) from non-invasive bloodless variables and/or blood lactate-related thresholds (BL_RTs) measured during an Incremental submaximal Shuttle Test (IST), and to determine whether the addition of a Constant Velocity Test (CVT) could improve the estimation. Seventy-five postmenopausal women conducted an IST to determine several BL_RTs and bloodless variables, and two to seven CVTs to determine _vMLSS. Determined BL_RTs were conventionally used lactate threshold (LT) measured either visually (_vLT_+0.1mM) or mathematically (_vLE_min), and 0.5, 1 and 1.5 mmol·L⁻¹ above LT, along with fixed BL_RTs. The best single predictor of _vMLSS (7.1 ± 1.0 km·h⁻¹) was _vLE_min+1.5mM (R² = 0.80, P < 0.001; SEE = 0.46 km·h⁻¹). The combination of BL_RTs and bloodless variables improved the estimation of _vMLSS (R² = 0.85, P < 0.001; SEE = 0.38 km·h⁻¹). The addition of a CVT still improved the prediction of _vMLSS up to 89.2%, with lower SEE (0.32 km·h⁻¹). This study suggests that _vLE_min-related thresholds obtained from a single submaximal IST are accurate estimates of _vMLSS in postmenopausal women, and thus the time-consuming procedure of _vMLSS testing could be avoided. Performing an additional CVT is encouraged because it improves the prediction of _vMLSS.

Objectives: To investigate how objectively measured physical activity (PA) levels differ according to absolute moderate intensity recommendation (3–6 METs) and relative to individual lactate thresholds (LT1 and LT2), and to verify if high‐fit women record higher PA levels compared to women with lower aerobic fitness.Methods: Seventy‐five postmenopausal women performed an incremental exercise test and several constant‐velocity tests wearing an accelerometer to identify the activity counts (ct min⁻¹) corresponding to LT1 and LT2. Individual linear regression determined activity counts cut‐points for each intensity: (1) sedentary ( LT2). Participants then wore an accelerometer during a week to measure the time spent at each PA intensity level.Results: According to absolute intensity categorisation, high‐fit postmenopausal women recorded twice as much time at moderate‐to‐vigorous PA (MVPA) (P < 0.01) than low‐fit women. However, when PA intensity was calculated relative to individual lactate thresholds, MVPA was significantly reduced by half (P < 0.01) and the data revealed no differences (P = 0.62) between groups (∼20 min day⁻¹ at MVPA).Conclusions: Accelerometer cut‐points derived from absolute moderate‐intensity recommendations overestimated MVPA. Similar time at MVPA was recorded by high‐ and low‐fit postmenopausal women when the cut‐points were tailored to individual lactate thresholds. A more accurate estimation of PA behaviour could be provided with the use of individually tailored accelerometer cut‐points.

The aim of this study was to determine the relationship between perceived respiratory and muscular training load (TL) and changes in physical fitness in elite and non-elite junior soccer players. Twenty-eight elite (n = 14, 17.6 ± 0.6 years, 70.3 ± 4.4 kg, 179.7 ± 5.6 cm) and non-elite (n = 14, 17.5 ± 0.5 years, 71.1 ± 6.5 kg, 178.1 ± 5.6 cm) soccer players belonging to a Spanish first and third division football academies and competing in junior Spanish first division (2012-2013) participated in the study. Countermovement jump (CMJ), CMJ arm swing, 5 and 15 m sprints and the Université de Montreal endurance test were performed in January and 9 weeks later in March. In order to quantify TLs, after each training session and match, players reported their session rating of perceived exertion (sRPE) separately for respiratory (sRPEres) and leg musculature (sRPEmus). Elite players accumulated greater weekly training volume (361 ± 14 vs. 280 ± 48 min; effect sizes (ES) = 5.23 ± 1.74; most likely), and perceived respiratory (1460 ± 184 vs. 1223 ± 260 AU; ES = 1.12 ± 0.79; very likely) and muscular (1548 ± 216 vs. 1318 ± 308 AU; ES = 0.99 ± 0.84; likely) TL than did non-elite players. Training volume, sRPEres-TL and sRPEmus-TL were positively and largely correlated (r = 0.67-0.71) with the changes in aerobic fitness. The present results suggest that a low training volume and TL can impair improvement in aerobic fitness in junior soccer players during the in-season period.

The optimal dose of physical activity (PA) in cancer survivors (CS) is unknown due to the large variety of types of cancer, illness stages and treatments, low cardiorespiratory fitness, and physical inactivity. It is recommended that CS follow current PA guidelines for healthy population. There are no specific exercise prescription guidelines for CS. To know the cardiorespiratory parameters of CS in order to create exercise prescription guidelines for this population, 152 inactive CS were recruited to perform a cardiopulmonary exercise test. Peak oxygen uptake (VO_2peak), ventilatory threshold (VT) and respiratory compensation point (RCP) determined 3 exercise intensity zones to create exercise intensity classification guidelines for CS. VO_2peak (18.7±4.6 mL·kg⁻¹·min⁻¹) and peak heart rate (HR_peak) (145.1±17.9 bpm) were lower than the estimated values (p2max, 55–70% HR_max, 23–48% HR_res, 2.5–4 METs and 8–14 points on RPE scale. Intensities in PA guidelines for healthy population are not adapted to the characteristics of CS. For individual exercise prescription in CS specific PA guidelines should be used in order to maximize the benefits obtained by the use of aerobic exercise training.