Objective To evaluate the effectiveness of low-volume high-intensity interval training(LV-HIIT)protocols defined by the W'Balance(W'BAL)model in achieving maximal activation of both anaerobic and aerobic energy systems.Methods Twenty-eight national-level athletes(age:20±1 years old;height:174±9 cm;weight:65.1±9.4 kg)completed an incremental exercise test,followed by six supra-critical power(supra-CP)and five sub-CP constant-load tests to determine VO2max,maximal accumulated oxygen deficit(MAOD),critical power(CP),and W prime(W').They then performed three randomly ordered LV-HIIT protocols(each of 4-minute total duration),with a 10-second inter-val for passive recovery between bouts.The protocols consisted of 10s(HIIT10/10),20s(HIIT20/10),and 30 s(HIIT30/10).Exercise intensities were individually prescribed using the W'BAL model.Accu-mulated oxygen deficit(AOD)and net AOD(NAOD)were calculated for each protocol.Results Final 10-s oxygen uptake(VO2)reached 77％,88％,and 89％of VO2max in HIIT10/10,HIIT20/10,and HIIT30/10,respectively(P<0.05).VO2 in HIIT10/10 was significantly lower than in HIIT20/10 and HIIT30/10(P<0.05),with no significant difference between the latter two(P>0.05).AOD did not differ significantly from MAOD among the three protocols(P>0.05),whereas NAOD was significantly lower than MAOD in all cases(P<0.05).Additionally,NAOD in HIIT10/10 was significantly lower than in HIIT20/10 and HI-IT30/10(P<0.05),with no significant difference between the latter two(P>0.05).Conclusion The HIIT20/10 and HIIT30/10 intensity established by the W'BAL model can substantially elicit maximal activation of both anaerobic and aerobic energy systems.While the W'BAL model demonstrates potential for set-ting exercise intensities in LV-HIIT,future studies are necessary to develop specific W'recovery rate models for targeted populations and to refine CP models that are better suited for intermittent exercises.

Objective To explore the effect of training weights on energy expenditure(EE)among young males during squatting.Methods Twenty young males with strength training experience≥1 year were recruited and performed 3 sets of squats,with 5 repetitions per set,at 40%1RM,60%1RM and 80%1RM,respectively,with an interval of at least 72 hours.Oxygen uptake(VO2),heart rate,blood lactate,and the mechanical work on the barbell during squat exercises were measured before,during,and after each sets.Moreover,one-way repeated-measures ANOVA was used to compare EE differenc-es between different training weights,and two-way ANOVA was employed to examine the weight×method effect on metabolic equivalent(MET)values.Meanwhile,Pearson's correlation analysis was conducted to examine the correlation between EE and barbell mechanical work.Results(1)Training weight has significant effects on the total energy expenditure and EE during excess post-exercise oxy-gen consumption(EPOC)stage(P<0.001),while a significant increase was observed in the glycolytic EE only at 80%1RM and the aerobic EE with no less than 60%1RM(P<0.01 and P<0.05).(2)The percentage of EPOC-stage and glycolytic EE in the total energy expenditure was significantly higher than the aerobic EE(P<0.01),while that of aerobic EE at 40%1RM and 60%1RM was significantly higher than at 80%1RM(P<0.01).(3)Total energy expenditure(r=0.65,P<0.001)and EPOC-stage EE(r=0.68,P<0.001)showed moderate correlation with the mechanical work done.(4)Aerobic EE was significantly lower than the mechanical work done during squatting(P<0.001).Moreover,the MET values of squats calculated using aerobic EE during exercise at 40%-80%1RM was 2.42±0.54,2.89±0.87 and 2.7±0.56,while the MET ones calculated using the total energy expenditure reached 14.99±2.94,20.52±4.51 and 28.57±6.88.Conclusions Only EPOC-stage and glycolytic EE elevate with the increase of weight.Moreover,EE and the MET value scalculated using VO2 dur-ing exercise may under estimate the actual intensity of squat.Meanwhile,the accuracy of EE estima-tion may be improved by introducing the mechanical work.

Objective To explore the effect of training weights on energy expenditure(EE)among young males during squatting.Methods Twenty young males with strength training experience≥1 year were recruited and performed 3 sets of squats,with 5 repetitions per set,at 40%1RM,60%1RM and 80%1RM,respectively,with an interval of at least 72 hours.Oxygen uptake(VO2),heart rate,blood lactate,and the mechanical work on the barbell during squat exercises were measured before,during,and after each sets.Moreover,one-way repeated-measures ANOVA was used to compare EE differenc-es between different training weights,and two-way ANOVA was employed to examine the weight×method effect on metabolic equivalent(MET)values.Meanwhile,Pearson's correlation analysis was conducted to examine the correlation between EE and barbell mechanical work.Results(1)Training weight has significant effects on the total energy expenditure and EE during excess post-exercise oxy-gen consumption(EPOC)stage(P<0.001),while a significant increase was observed in the glycolytic EE only at 80%1RM and the aerobic EE with no less than 60%1RM(P<0.01 and P<0.05).(2)The percentage of EPOC-stage and glycolytic EE in the total energy expenditure was significantly higher than the aerobic EE(P<0.01),while that of aerobic EE at 40%1RM and 60%1RM was significantly higher than at 80%1RM(P<0.01).(3)Total energy expenditure(r=0.65,P<0.001)and EPOC-stage EE(r=0.68,P<0.001)showed moderate correlation with the mechanical work done.(4)Aerobic EE was significantly lower than the mechanical work done during squatting(P<0.001).Moreover,the MET values of squats calculated using aerobic EE during exercise at 40%-80%1RM was 2.42±0.54,2.89±0.87 and 2.7±0.56,while the MET ones calculated using the total energy expenditure reached 14.99±2.94,20.52±4.51 and 28.57±6.88.Conclusions Only EPOC-stage and glycolytic EE elevate with the increase of weight.Moreover,EE and the MET value scalculated using VO2 dur-ing exercise may under estimate the actual intensity of squat.Meanwhile,the accuracy of EE estima-tion may be improved by introducing the mechanical work.

Objective To evaluate the effectiveness of low-volume high-intensity interval training(LV-HIIT)protocols defined by the W'Balance(W'BAL)model in achieving maximal activation of both anaerobic and aerobic energy systems.Methods Twenty-eight national-level athletes(age:20±1 years old;height:174±9 cm;weight:65.1±9.4 kg)completed an incremental exercise test,followed by six supra-critical power(supra-CP)and five sub-CP constant-load tests to determine VO2max,maximal accumulated oxygen deficit(MAOD),critical power(CP),and W prime(W').They then performed three randomly ordered LV-HIIT protocols(each of 4-minute total duration),with a 10-second inter-val for passive recovery between bouts.The protocols consisted of 10s(HIIT10/10),20s(HIIT20/10),and 30 s(HIIT30/10).Exercise intensities were individually prescribed using the W'BAL model.Accu-mulated oxygen deficit(AOD)and net AOD(NAOD)were calculated for each protocol.Results Final 10-s oxygen uptake(VO2)reached 77％,88％,and 89％of VO2max in HIIT10/10,HIIT20/10,and HIIT30/10,respectively(P<0.05).VO2 in HIIT10/10 was significantly lower than in HIIT20/10 and HIIT30/10(P<0.05),with no significant difference between the latter two(P>0.05).AOD did not differ significantly from MAOD among the three protocols(P>0.05),whereas NAOD was significantly lower than MAOD in all cases(P<0.05).Additionally,NAOD in HIIT10/10 was significantly lower than in HIIT20/10 and HI-IT30/10(P<0.05),with no significant difference between the latter two(P>0.05).Conclusion The HIIT20/10 and HIIT30/10 intensity established by the W'BAL model can substantially elicit maximal activation of both anaerobic and aerobic energy systems.While the W'BAL model demonstrates potential for set-ting exercise intensities in LV-HIIT,future studies are necessary to develop specific W'recovery rate models for targeted populations and to refine CP models that are better suited for intermittent exercises.

Objective To compare the effectiveness of the heart rate variability threshold(HRVT),muscle oxygenation threshold(MOT),and their combined threshold(COMT)in predicting the ventila-tory threshold(VT)and lactate threshold(LT).Methods Twenty male athletes at or above the nation-al level were recruited to perform an incremental exercise test to determine VT and LT,during which gas exchange,muscle oxygenation,and heart rate variability were collected.The HRVT,MOT,and COMT methods were then applied,and their predictive validity was evaluated by comparing the correla-tions and agreements between heart rate(HR)and power output(PO)at VT and LT.Results For HR,VT1 showed strong correlation and agreement with MOT1(r=0.958,ICC=0.944)and COMT1(r=0.957,ICC=0.951),with COMT1 having the smallest mean bias(1.4 bpm)and the narrowest limits of agreement(LOA)(-5.4 to 8.2 bpm).Moreover,VT2 demonstrated the highest correlation and agree-ment with COMT2(r=0.985,ICC=0.982),with a mean bias of-0.7 bpm and LOA of-5.0 to 3.7 bpm.Meanwhile,LT showed high correlation and good agreement with COMT2(r=0.884,ICC=0.754)and MOT2(r=0.886,ICC=0.738),with mean biases of-6.8 bpm and-7.3 bpm,and LOA of-17.5 to 3.8 bpm and-17.9 to 3.2 bpm,respectively.For PO,VT1 had the best correlation and agreement with MOT1(r=0.836,ICC=0.808),with a mean bias of-0.2 W and LOA of-11.7 to 11.3 W.VT2 performed best correlation and agreement with COMT2(r=0.910,ICC=0.900),with a mean bias of 2.3 W and LOA of-8.9 to 13.5 W.In LT prediction,MOT2(r=0.736,ICC=0.692)outperformed COMT2(r=0.635,ICC=0.618),with mean biases of-2.6 W and 0.2 W,and LOA of-26.0 to 20.7 W and-26.6 to 27.1 W,respectively.Conclusion All three indicators—HRVT,MOT,and COMT—demonstrates high validity in predicting VT and LT.MOT1 performs best for predicting PO at VT1,while COMT2 shows the highest consistency for predicting both HR and PO at VT2.Howev-er,for LT prediction,MOT2 is more advantageous for predicting PO,whereas COMT2 is more accu-rate for predicting HR.Therefore,method selection should be tailored to the specific threshold type and measurement target.

Objective To compare the effectiveness of the heart rate variability threshold(HRVT),muscle oxygenation threshold(MOT),and their combined threshold(COMT)in predicting the ventila-tory threshold(VT)and lactate threshold(LT).Methods Twenty male athletes at or above the nation-al level were recruited to perform an incremental exercise test to determine VT and LT,during which gas exchange,muscle oxygenation,and heart rate variability were collected.The HRVT,MOT,and COMT methods were then applied,and their predictive validity was evaluated by comparing the correla-tions and agreements between heart rate(HR)and power output(PO)at VT and LT.Results For HR,VT1 showed strong correlation and agreement with MOT1(r=0.958,ICC=0.944)and COMT1(r=0.957,ICC=0.951),with COMT1 having the smallest mean bias(1.4 bpm)and the narrowest limits of agreement(LOA)(-5.4 to 8.2 bpm).Moreover,VT2 demonstrated the highest correlation and agree-ment with COMT2(r=0.985,ICC=0.982),with a mean bias of-0.7 bpm and LOA of-5.0 to 3.7 bpm.Meanwhile,LT showed high correlation and good agreement with COMT2(r=0.884,ICC=0.754)and MOT2(r=0.886,ICC=0.738),with mean biases of-6.8 bpm and-7.3 bpm,and LOA of-17.5 to 3.8 bpm and-17.9 to 3.2 bpm,respectively.For PO,VT1 had the best correlation and agreement with MOT1(r=0.836,ICC=0.808),with a mean bias of-0.2 W and LOA of-11.7 to 11.3 W.VT2 performed best correlation and agreement with COMT2(r=0.910,ICC=0.900),with a mean bias of 2.3 W and LOA of-8.9 to 13.5 W.In LT prediction,MOT2(r=0.736,ICC=0.692)outperformed COMT2(r=0.635,ICC=0.618),with mean biases of-2.6 W and 0.2 W,and LOA of-26.0 to 20.7 W and-26.6 to 27.1 W,respectively.Conclusion All three indicators—HRVT,MOT,and COMT—demonstrates high validity in predicting VT and LT.MOT1 performs best for predicting PO at VT1,while COMT2 shows the highest consistency for predicting both HR and PO at VT2.Howev-er,for LT prediction,MOT2 is more advantageous for predicting PO,whereas COMT2 is more accu-rate for predicting HR.Therefore,method selection should be tailored to the specific threshold type and measurement target.

Objective:To explore the value of ultrasound imaging characteristics combined with clinical indicators in assessing the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC).Methods:A retrospective analysis was conducted for patients who underwent pancreatic contrast-enhanced ultrasound (CEUS) from September 2017 to October 2023 at Peking Union Medical College Hospital and were diagnosed with PDAC based on pathological findings. Various parameters were recorded, including CA19-9 levels, tumor size, location, morphologic features, echogenicity, presence of internal cystic components, dilatation of the main pancreatic duct, peripheral vascular invasion, CEUS characteristics, presence or absence of liver metastasis, and treatment methods. In April 2024, patient survival information was obtained through telephone follow-up or review of medical records. Based on the results of the cox regression model analysis, a nomogram model of the risk of death was developed. The receiver operating characteristic (ROC) curves were applied to evaluate the predictive efficacy of the model. The calibration curves were plotted to evaluate the accuracy of the model, and clinical decision curves were used to evaluate the clinical benefit of the model.Results:This study included a total of 207 patients with PDAC. As of April 2024, 71 patients were alive and 136 died, with a median survival time of 14 months (95% CI: 12 -17). Multivariate analysis confirmed that the elevated CA19-9 ( HR=1.689, 95% CI: 1.102-2.588), tumor size >4 cm ( HR=1.641, 95% CI: 1.159-2.322), taller-than-wide shapes ( HR=1.450, 95% CI: 1.019-2.065), incomplete hypo-enhancement ( HR=1.618, 95% CI: 1.100-2.380), and liver metastasis ( HR=1.687, 95% CI: 1.175-2.423) were independent risk factors for survival in patients with PDAC. A nomogram model was further constructed for 6-month, 12-month and 3-year survival of patients with PDAC. The areas under the ROC curve were 0.679, 0.705 and 0.815, respectively. The calibration curves suggested that the model was more accurate, and the clinical decision curves showed that the model had a better clinical benefit. Conclusion:The combined use of ultrasound imaging characteristics and clinical indicators could effectively predict the prognosis of PDAC patients. Specifically, tumor size >4 cm, taller-than-wide shapes, incomplete hypo-enhancement, elevated CA19-9, and the presence of liver metastasis are correlated with poorer survival outcomes. The nomogram model constructed on the basis of these factors can be used to assess the survival of patients with PDAC.

Objective: To explore the distribution of traditional Chinese medicine (TCM) syndromes in patients with interstitial lung disease (ILD) and its influencing factors. Methods: This cross-sectional study included 385 patients with ILD admitted to the First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine) from January 2018 to June 2022. Data on sex, age, body mass index, smoking history, respiratory rate, hospitalization time, treatment cost, whether velcro rales can be heard, comorbidities with rheumatic immune diseases, TCM four examination information, and clinical examination results, including CT imaging, D-dimer level, and lung function-related indicators, were collected. The distribution pattern of TCM syndromes in patients with ILD and the association between TCM syndromes and clinical indicators were analyzed using the cluster analysis and binary Logistic regression analysis. Results: Among the 385 patients with ILD, sticky phlegm (59.74%) and shortness of breath (56.10%) were common symptoms, while greasy tongue coating (55.32%), red tongue (52.73%), and slippery and rapid pulse (25.71%) were common tongue and pulse manifestations. The patients were divided into five syndromes using cluster analysis: syndrome of phlegm-heat stagnation in the lung (36.62%), syndrome of turbid phlegm obstructing lung (29.35%), syndrome of deficiency of both qi and yin (12.99%), syndrome of qi deficiency of lung and kidney (11.95%), and syndrome of phlegm and blood stasis obstructing lung (9.09%). The D-dimer level was lower in patients with syndrome of phlegm-heat stagnation in the lung, syndrome of turbid phlegm obstructing lung, syndrome of deficiency of both qi and yin, and syndrome of qi deficiency of lung and kidney than in those with syndrome of phlegm and blood stasis obstructing lung (P<0.05). The percentage of predicted forced vital capacity (FVC%pred) of patients with syndrome of phlegm-heat stagnation in the lung, syndrome of turbid phlegm obstructing lung, syndrome of deficiency of both qi and yin, and syndrome of phlegm and blood stasis obstructing lung was higher than in those with syndrome of qi deficiency of lung and kidney (P<0.05). Among patients aged 60 and above, those with syndrome of phlegm-heat stagnation in the lung, syndrome of phlegm and blood stasis obstructing lung, and syndrome of deficiency of both qi and yin containing dual pathogenic syndrome elements were more likely to experience moderate to severe pulmonary diffusion impairment than those with syndrome of turbid phlegm obstructing lung and syndrome of qi deficiency of lung and kidney containing single pathogenic syndrome elements (P<0.05). The Logistic regression showed that the FVC%pred was an influential factor for syndrome of qi deficiency of lung and kidney, and the area under the receiver operating characteristic (ROC) curve (AUC) between FVC%pred and the formation of syndrome of qi deficiency of lung and kidney was 0.676 (95%CI: 0.598-0.755), P=0.002. The sensitivity was 0.431, the specificity was 0.966, and the best threshold on the ROC curve of 0.397 was 79.1%. The D-dimer level was an influential factor in the formation of syndrome of phlegm and blood stasis obstructing lung. The AUC between D-dimer level and the formation of syndrome of phlegm and blood stasis obstructing lung was 0.729 (95%CI: 0.655-0.802), P<0.001. The sensitivity was 0.914, the specificity was 0.523, and the best threshold on the ROC curve of 0.437 was 0.675 mg/L. Conclusion syndrome of phlegm-heat stagnation in the lung and syndrome of turbid phlegm obstructing lung are common among patients with ILD. Complex pathological syndromes are more likely to exacerbate pulmonary diffusion dysfunction. The FVC%pred can assist in differentiating syndrome of qi deficiency of lung and kidney, whereas the D-dimer level can assist in differentiating syndrome of phlegm and blood stasis obstructing lung.

Objective:To analyze the trabecular bone score (TBS) and its association with muscle health in the postmenopausal population.Methods:It was a cross-sectional study. A total of 214 postmenopausal individuals who underwent dual-energy X-ray absorptiometry testing at the Beijing Research Institute of Sports Science between January and December 2023 were consecutively included. The participants were divided into two groups based on the presence or absence of osteoporosis (OP): 62 cases in the OP group and 152 cases in the non-OP group. All subjects completed body composition assessments and scans of bilateral hip and lumbar spine bone mineral density (BMD)(All the BMD in this study were areal BMD). Demographic data, including age, age at menarche, age at menopause, and fracture history, were also collected. TBS was calculated using the TBS iNsight software. Muscle health indicators included upper limb, lower limb, trunk, and total muscle mass, lean body mass, appendicular skeletal muscle mass index (ASMI), and grip strength. The Pearson correlation analysis was used to determine the relationship between TBS and muscle health indicators, as well as between TBS and the BMD of lumbar spine (L 1-4). Further, multiple linear regression analysis was conducted to explore the independent association between TBS and muscle health indicators. Results:TBS, lean body mass, ASMI, grip strength, and muscle mass of the upper limb, lower limb, trunk, whole body in the OP group were all lower than those in the non-OP group [(1.27±0.07) vs (1.35±0.07) score, (36.64±3.45) vs (39.14±3.62) kg, (6.16±0.56) vs (6.44±0.63) kg/m2, (23.87±3.31) vs (25.34±4.33) kg, (3.54±0.47) vs (3.78±0.47) kg, (11.70±1.33) vs (12.68±1.49) kg, (16.57±1.68) vs (17.50±1.69) kg, and (34.91±3.33) vs (37.13±3.47) kg] (all P<0.05). Pearson analysis showed that TBS was positively correlated with lean body mass, ASMI, grip strength, and muscle mass of the upper limb, lower limb, whole body (all P<0.05). TBS was negatively correlated with age ( P<0.01). TBS was positively correlated with the BMD of lumbar spine (L 1-4) ( r=0.660, P<0.01). Multiple regression analysis demonstrated that ASMI was positively correlated with TBS ( β=0.284, P<0.01). Conclusion:In the postmenopausal population, individuals with OP have lower TBS. Furthermore, TBS is closely associated with muscle health.

Objective:To explore the value of ultrasound imaging characteristics combined with clinical indicators in assessing the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC).Methods:A retrospective analysis was conducted for patients who underwent pancreatic contrast-enhanced ultrasound (CEUS) from September 2017 to October 2023 at Peking Union Medical College Hospital and were diagnosed with PDAC based on pathological findings. Various parameters were recorded, including CA19-9 levels, tumor size, location, morphologic features, echogenicity, presence of internal cystic components, dilatation of the main pancreatic duct, peripheral vascular invasion, CEUS characteristics, presence or absence of liver metastasis, and treatment methods. In April 2024, patient survival information was obtained through telephone follow-up or review of medical records. Based on the results of the cox regression model analysis, a nomogram model of the risk of death was developed. The receiver operating characteristic (ROC) curves were applied to evaluate the predictive efficacy of the model. The calibration curves were plotted to evaluate the accuracy of the model, and clinical decision curves were used to evaluate the clinical benefit of the model.Results:This study included a total of 207 patients with PDAC. As of April 2024, 71 patients were alive and 136 died, with a median survival time of 14 months (95% CI: 12 -17). Multivariate analysis confirmed that the elevated CA19-9 ( HR=1.689, 95% CI: 1.102-2.588), tumor size >4 cm ( HR=1.641, 95% CI: 1.159-2.322), taller-than-wide shapes ( HR=1.450, 95% CI: 1.019-2.065), incomplete hypo-enhancement ( HR=1.618, 95% CI: 1.100-2.380), and liver metastasis ( HR=1.687, 95% CI: 1.175-2.423) were independent risk factors for survival in patients with PDAC. A nomogram model was further constructed for 6-month, 12-month and 3-year survival of patients with PDAC. The areas under the ROC curve were 0.679, 0.705 and 0.815, respectively. The calibration curves suggested that the model was more accurate, and the clinical decision curves showed that the model had a better clinical benefit. Conclusion:The combined use of ultrasound imaging characteristics and clinical indicators could effectively predict the prognosis of PDAC patients. Specifically, tumor size >4 cm, taller-than-wide shapes, incomplete hypo-enhancement, elevated CA19-9, and the presence of liver metastasis are correlated with poorer survival outcomes. The nomogram model constructed on the basis of these factors can be used to assess the survival of patients with PDAC.