ECSS Paris 2023: OP-MH15
INTRODUCTION: High-Intensity Multimodal Training (HIMT) is promoted as a time‑efficient method for meeting physical activity guidelines by combining high-intensity aerobic and resistance exercise within a single session. However, poor standardisation in prescription and reporting has limited comparisons with other combined training modes (e.g., Inter‑Session Concurrent Training [ISCT]). This study examined the feasibility, acceptability, physical and biochemical outcomes of a 7‑week HIMT intervention compared to an active matched ISCT control, delivered across three community sites. METHODS: A two‑arm parallel randomised controlled trial was conducted. Recreationally active adults were allocated to HIMT (4 × 45‑min sessions/week of combined aerobic and resistance exercise in a circuit format) or ISCT (2 × 45‑min resistance circuits + 2 × 45‑min aerobic circuits/week). Training volume, session duration, exercise intensity (RPE ≥ 7/10 [CR‑10]) and exercise selection were matched between groups. Feasibility and acceptability were evaluated using a convergent mixed-methods approach, integrating qualitative data (thematic content analysis of open-ended survey responses) and quantitative data (Likert scale scores, training session intensity, retention). Physical outcomes (maximal strength, aerobic capacity, anthropometry, body composition) and acute and chronic exercise-induced biochemical responses (cortisol, testosterone, growth hormone) were assessed using linear mixed effect models, pre to-post intervention. A priori sample size n = 47 (α=0.05, power =0.80, f=0.42). RESULTS: 79 participants were randomised and 75 completed post-testing (HIMT n=39, ISCT n=36). Participants attended 91.4% of sessions, with an average training S-RPE of 7.47 ± 1.40. The program was safe, tolerable and enjoyable. Both groups showed small within‑group improvements in lower and upper‑body strength, peak oxygen uptake, and maximum work rate, alongside trivial improvements in fat mass, body fat percentage, lean mass, and waist circumference (p<0.05). A modest group × time interaction favoured ISCT for reduced body fat percentage (b=-0.628, 95% CI [-1.21 to -0.046], p=0.035, d=−0.082). An attenuated exercise-induced growth hormone response was observed following 7-weeks of ISCT compared to HIMT in females only (b= -8.135, 95% CI [-14.737 to -1.533], p=0.017, d=-0.836). Further expected biochemical responses were observed in both groups. CONCLUSION: HIMT is a safe, feasible and acceptable intervention for recreationally active adults, eliciting meaningful physical adaptations over 7-weeks. Both training modes produced expected biochemical adaptations, with more pronounced exercise-induced hormonal responses in females. These findings support the use of HIMT to promote structured exercise engagement and physical fitness, while advancing community based prescription standards for combined training. This may inform future implementation of scalable, time efficient models to promote population health and fitness.
Read CV Tijana SharpECSS Paris 2023: OP-MH15
INTRODUCTION: Physical activity (PA) is associated with major health benefits. Since 2020, the World Health Organization no longer requires PA to be accumulated in bouts of at least 10 minutes. Thus, brief and intermittent episodes now contribute to recommendations (Bull et al., 2020). However, many wearables still rely on 60-s epoch aggregation due to historical technical constraints and alignment with previous guidelines. Such temporal resolution is poorly suited to capture the highly fragmented nature of daily-life PA (Taoum et al., 2021). Moreover, most validation studies are conducted in controlled settings, limiting ecological validity (Giurgiu et al., 2025). Although newer approaches use shorter epochs, few studies have directly compared these methods under free-living conditions. This study compared the validity of several devices and analytical methods to detect walking bouts and classify their intensity in free-living conditions using video-recorded direct observation. METHODS: Sixty healthy adults (20–80 years, balanced by sex and decade) simultaneously wore six devices for seven days: activPAL (thigh), StepWatch4 (ankle), ActiGraph wGT3X-BT (hip and wrist), Fitbit Charge 5 and Inspire 2 (hip and wrist), and Garmin Vívoactive 4S (wrist). A total of 119 free-living sessions were annotated by two raters (>150 h; 10,194 walking bouts; gold standard). For each device, commonly used analytical approaches were tested. Cadence (steps·min⁻¹) derived from detected steps was used to classify intensity (Tudor-Locke et al., 2019). Sensitivity, specificity, and weighted accuracy were computed for walking detection and intensity classification. RESULTS: Three main findings emerged: (1) Aggregation ≥60 s overestimates walking duration and underestimates cadence, leading to an underestimation of moderate-to-vigorous PA in favor of light PA; (2) With high temporal resolution (≤1 s), validity generally depends on sensor location, with thigh-, hip-, and ankle-worn devices better detecting short bouts; however, the wrist-worn StepCount-SSL algorithm (Small et al., 2024) achieved validity comparable to lower-limb and hip placements; (3) At identical location and resolution, analytical choices (counts, vector magnitude, raw-signal-based or machine-learning methods) substantially affect validity. CONCLUSION: Free-living walking is highly fragmented. Ignoring short bouts lead to misestimating walking intensity, a key parameter of PA guidelines. In most cases, combining lower-limb or hip placement with high temporal resolution better reflects real-world walking dynamics. However, advanced wrist-based machine-learning approaches such as StepCount-SSL may overcome traditional wrist-placement limitations. To accurately characterize intermittent walking in daily life, we recommend: (1) high temporal resolution approaches (≤1 s or event-based detection), and (2) sensor placement on the hip, thigh, or ankle, or the use of sufficiently validated wrist-based machine-learning algorithms (e.g., StepCount-SSL).
Read CV Germain FaityECSS Paris 2023: OP-MH15
INTRODUCTION: Cadmium is a widespread environmental pollutant associated with various adverse health outcomes. Physical activity (PA) may play the potential moderating role in associations between blood cadmium (BC) and mortality risk. This study aims to examine: (1) the associations between PA, BC and all-cause mortality, cardiovascular disease (CVD) mortality, or cancer mortality risk; and (2) the counteracting effect of different PA levels on the risk of mortality caused by BC. METHODS: We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2007-2018, including 22,821 adults. PA levels were assessed using the Global Physical Activity Questionnaire, and BC was measured by inductively coupled plasma mass spectrometry. Cox proportional hazards models and restricted cubic spline models (RCS) were employed for statistical analysis. RESULTS: After adjusting for all covariates, compared with the inactive PA group, the insufficiently active PA or sufficiently active PA group had a 33% or 47% lower risk of all-cause mortality, a 35% or 44% lower risk of CVD mortality, and a 32% or 31% lower risk of cancer mortality, respectively. Compared with the minimal blood cadmium level (Min-BCL) group, the high blood cadmium level (H-BCL) group had a 101% higher risk of all-cause mortality, a 72% higher risk of CVD mortality, and a 97% higher risk of cancer mortality. When combining PA and BC, compared with the Min-BCL group, the H-BCL respectively combined with insufficiently active PA or sufficiently active PA had a 103% or 46% higher risk of all-cause mortality, a 115% or 56% higher risk of cancer mortality. while no significant associations were observed between the combinations of H-BCL with insufficiently active PA or sufficiently active PA and the risk of CVD mortality. RCS analysis revealed that, for participants engaging inactive PA, insufficiently active PA or sufficiently active PA, the blood cadmium levels (BCLs) at HR = 1 were 0.07, 0.25, or 0.36 ug/L for all-cause mortality; 0.07, 0.29, or 0.36 ug/L for CVD mortality; and 0.18, 0.36, or 0.36 ug/L for cancer mortality. CONCLUSION: Both insufficiently active PA and sufficiently active PA can decrease the risk of all-cause, CVD, or cancer mortality, while H-BCL can increase these mortality risks. Importantly, PA can moderate the associations of BC and these mortality risks. We recommend promoting PA as a potential public health strategy to reduce cadmium-related mortality risks.
Read CV Hou XiaoECSS Paris 2023: OP-MH15