Regular physical activity (PA) is beneficial to young people's health and development. In order to provide nationally representative and internationally comparable evidence on youth PA, China has participated in Global Matrix 2.0 and 3.0. The purpose of this study is to report the updated results of China's Report Card on PA for Children and Adolescents. The grades were assigned by results derived from the PA and Fitness in China––The Youth Study (PAFCTYS), conducted from October to December in 2020. The data from PAFCTYS 2020 included a nationally representative sample of Chinese school-aged children (n = 133,006, boys: 49.6%, aged 9–17 years). Self-report questionnaires were completed by the sampled students, their parents/guardians (n = 133,006), and physical education teachers (n = 1036) from each sampled school respectively. The grades of China 2022 Report Card are Overall PA (C), Organized Sport Participation (F), Active Play (C-), Active Transportation (C), Sedentary behaviors (C), Physical Fitness (INC), Family and Peers (C-), School (D), Community and Environment (D-), and Government (D). Levels of PA among Chinese youth were low and most young people were below the recommended guidelines, although the grade of Overall PA has been improved since the modified benchmark. Prevalence of sedentary behaviors remained high. Interventions and policies at the community and environment level should be encouraged to promote PA and reduce sedentary behaviors. In addition, national policies on young people's PA should be advocated widely to ensure the policies can be transferred into action.

Background: The rapid advancements in science and technology of wrist-wearable activity devices offer considerable potential for clinical applications. Self-monitoring of physical activity (PA) with activity devices is helpful to improve the PA levels of adolescents. However, knowing the accuracy of activity devices in adolescents is necessary to identify current levels of PA and assess the effectiveness of intervention programs designed to increase PA. Objective: The study aimed to determine the validity of the 11 commercially available wrist-wearable activity devices for monitoring total steps and total 24-hour total energy expenditure (TEE) in healthy adolescents under simulated free-living conditions. Methods: Nineteen (10 male and 9 female) participants aged 14 to 18 years performed a 24-hour activity cycle in a metabolic chamber. Each participant simultaneously wore 11 commercial wrist-wearable activity devices (Mi Band 2 [XiaoMi], B2 [Huawei], Bong 2s [Meizu], Amazfit [Huamei], Flex [Fitbit], UP3 [Jawbone], Shine 2 [Misfit], GOLiFE Care-X [GoYourLife], Pulse O2 [Withings], Vivofit [Garmin], and Loop [Polar Electro]) and one research-based triaxial accelerometer (GT3X+ [ActiGraph]). Criterion measures were total EE from the metabolic chamber (mcTEE) and total steps from the GT3X+ (AGsteps). Results: Pearson correlation coefficients r for 24-hour TEE ranged from .78 (Shine 2, Amazfit) to .96 (Loop) and for steps ranged from 0.20 (GOLiFE) to 0.57 (Vivofit). Mean absolute percent error (MAPE) for TEE ranged from 5.7% (Mi Band 2) to 26.4% (Amazfit) and for steps ranged from 14.2% (Bong 2s) to 27.6% (Loop). TEE estimates from the Mi Band 2, UP3, Vivofit, and Bong 2s were equivalent to mcTEE. Total steps from the Bong 2s were equivalent to AGsteps. Conclusions: Overall, the Bong 2s had the best accuracy for estimating TEE and total steps under simulated free-living conditions. Further research is needed to examine the validity of these devices in different types of physical activities under real-world conditions.

Chronic pain is a significant and complex health condition characterized by persistent or recurrent pain lasting more than three months. Exercise-based rehabilitation is an effective non-pharmacological intervention, yet its underlying mechanisms have not been fully elucidated. This review systematically maps the molecular pathways of exercise-induced analgesia onto the pathophysiological cascades of chronic pain, aiming to fill a key gap in the current literature. It explores the molecular and cellular mechanisms underpinning the pathophysiology of chronic pain, indicating that the persistence of chronic pain stems from peripheral sensitization driven by inflammatory mediators and central sensitization involving glial cell activation and N-methyl-D-aspartate (NMDA) receptor-mediated neuroplasticity. Exercise can interrupt these pathological cascades through multi-system adaptations, including activation of the endogenous opioid and serotonergic systems activation and anti-inflammation. However, a significant gap remains in translating this mechanistic understanding of chronic pain into optimized, personalized exercise prescriptions, requiring future research into different exercise modalities, sex-specific responses, and the impact of comorbidities.

The aim of this study was to assess the effects of short-term high-intensity interval training (HIIT) and moderate-intensity continuous aerobic training (MICT) with matched energy expenditure on metabolic flexibility and other metabolic parameters in adult male individuals with obesity. Twenty male individuals with obesity (age: 21.4 ± 1.5 years; body mass index: 31.0 ± 3.6 kg/m²) were enrolled in this crossover design study. Participants were randomly allocated to an intervention sequence of 1) 3 consecutive days of HIIT (30 min, 6 × 2.5 min bouts at 90 % Peak Oxygen Uptake (VO_2peak), alternated with 2.5 min active recovery periods [25 % VO_2peak]), or 2) three consecutive days of MICT (60 min at 50 % VO_2peak), with a washout period of 1 week. Respiratory quotient (RQ), glucose, C-peptide, insulin, and non-esterified fatty acid (NEFA) levels were measured both during fasting and throughout a 180 min oral glucose tolerance test (OGTT), conducted before and after the intervention. The incremental area under the curve (iAUC) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) were derived. ΔRQ was defined as the average RQ during the OGTT minus fasting RQ. Short-term exercise intervention significantly reduced HOMA-IR in male individuals with obesity (P < 0.001) and concurrently increased the Matsuda index (P = 0.001). Both exercise interventions led to a similar decrease in fasting RQ (P = 0.001), C-peptide, insulin, and HOMA-IR (P < 0.001). Additionally, they reduced the iAUC for glucose and insulin during the OGTT (P < 0.001). The ΔRQ and the RQ iAUC in the HIIT group were significantly higher than those in the MICT group, and different exercise intensities exhibited interactive effects within groups for RQ iAUC and ΔRQ (P = 0.013 and P = 0.012). Two short-term exercise interventions similarly improved glucose tolerance, with HIIT demonstrating a more advantageous effect on metabolic flexibility than MICT in male individuals with obesity. The trial was officially registered at www.chictr.org.cn (ChiCTR2300072884).

To compare 26-h glycemic responses to uninterrupted sitting versus hourly brisk walking breaks and an alternating walking–resistance break strategy in sedentary young adults, with exploratory sensitivity analyses adjusting for energy expenditure (EE). Eighteen sedentary, healthy young adults (11 female; age, mean (SD) = 23.7 (2.5) years; BMI, 21.2 (2.0) kg/m²) completed three 26-h laboratory protocols in a randomized crossover design. Each protocol included a 22-h stay in a metabolic chamber and one 9-h intervention: uninterrupted sitting (SIT), 8-min bouts of brisk walking at 60% VO₂max every 60 min (WALK), or alternating 8-min bouts of simple resistance activities and brisk walking every 60 min (RESWALK). Interstitial glucose was recorded every 5 min by continuous glucose monitoring across the all three 26-h trials; the primary outcome was 26-h glucose incremental area under the curve (iAUC). The primary outcome, 26-h glucose iAUC, showed a significant condition effect (overall p = 0.039). Compared with SIT, RESWALK reduced 26-h iAUC by 17.3% (Cohen's d = −0.61, 95% CI −1.09 to −0.12; p = 0.043), while the reduction in WALK was not significant; these effects were attenuated after adjusting for EE (p = 0.085). For secondary outcomes, both WALK and RESWALK reduced glucose iAUC during the 9-h intervention window (p ≤ 0.027), with RESWALK being more effective than WALK (p = 0.021). However, during the 5-h evening period, iAUC was higher in WALK compared with SIT (p = 0.011), while no differences were observed during the 8-h sleep period. Regarding glucose variability, only CONGA_1 was significantly lower in RESWALK versus SIT (p ≤ 0.041). Compared with prolonged sitting, interrupting sedentary behavior with hourly breaks of combined walking and resistance exercises improves 26-h glycemic control in healthy young adults, EE-adjusted sensitivity analyses attenuated the 26-h effect. Walking-only breaks provided daytime benefits but did not significantly improve 26-h glucose exposure. ChiCTR1800019120.