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This study aimed to assess if, during incremental exercise, considering individual characteristics can make the relationship between the percentages of heart rate (HRR) and oxygen uptake (V̇O2R) reserve either 1:1 or more accurate. Cycle ergometer data of the maximal incremental exercise tests performed by 450 healthy and sedentary participants (17-66 years) of the HERITAGE Family Study, grouped for sex, ethnicity, age, body fat, resting HR, and V̇O2max, were used to calculate the individual linear regressions between %HRR and %V̇O2R. The mean slope and intercept of the individual linear regressions of each subgroup were compared with 1 and 0 (identity line), respectively, using Hotelling tests followed by post-hoc one-sample t-tests. Two multiple linear regressions were also performed, using either the slopes or intercepts of the individual linear regressions as dependent variables and sex, age, resting HR, and V̇O2max as independent variables. The mean %HRR-%V̇O2R relationships of all subgroups differed from the identity line. Moreover, individual linear regression intercepts (8.9 ± 16.0) and slopes (0.971 ± 0.190) changed (p < 0.001) after 20 weeks of aerobic training (13.1 ± 11.1 and 0.891 ± 0.122). The multiple linear regressions could explain only 3.8% and 1.3% of the variance in the intercepts and slopes, whose variability remained high (standard error of estimate of 15.8 and 0.189). In conclusion, the %HRR-%V̇O2R relationship differs from the identity line regardless of individual characteristics and their difference increased after aerobic training. Moreover, due to the high interindividual variability, using a single equation for the whole population seems not suitable for representing the %HRR-%V̇O2R relationship of a given subject, even when several individual characteristics are considered. Highlights The association between %HRR and %V̇O2R is not 1:1 even when individuals are grouped by age, sex, ethnicity, body composition, HRrest, and V̇O2max. Using several subject characteristics to identify the individual's %HRR-%V̇O2R relationship does not meaningfully increase its prediction accuracy or reduce the interindividual variability of %HRR-%V̇O2R relationships Using a single equation for the whole population is not suitable for representing the relationship of a given subject; hence, individual relationships should be preferred when prescribing the intensity of aerobic exercise. The individual %HRR-%V̇O2R relationship should be periodically assessed due to the potential training induced changes in the relationship. [ABSTRACT FROM AUTHOR]

Disruptions to muscle protein turnover and metabolic regulation contribute to muscle wasting during the progression of cancer cachexia. The initiation of cachexia is also associated with decreased physical activity. While chronic muscle AMPK activation occurs during cachexia progression in ApcMin/+ (MIN) mice, a preclinical cachexia model, the understanding of muscle AMPK's role during cachexia initiation is incomplete. Therefore, we examined if voluntary wheel exercise could improve skeletal muscle AMPK signaling in pre‐cachectic MIN mice. Next, we examined muscle AMPK's role in aberrant catabolic signaling in response to a 12‐h fast in mice initiating cachexia. Male C57BL/6 (B6: N = 26) and MIN (N = 29) mice were subjected to ad libitum feeding, 12‐h fast, or 4 wks. of wheel access and then a 12‐h fast during the initiation of cachexia. Male tamoxifen‐inducible skeletal muscle AMPKα1α2 (KO) knockout mice crossed with ApcMin/+ and floxed controls were examined (WT: N = 8, KO: N = 8, MIN: N = 10, MIN KO: N = 6). Male mice underwent a 12‐h fast and the gastrocnemius muscle was analyzed. MIN gastrocnemius mass was reduced compared to B6 mice. A 12‐h fast induced MIN muscle AMPKT172, FOXOS413, and ULK‐1S555 phosphorylation compared to B6. Wheel running attenuated these inductions. A 12‐h fast induced MIN muscle MuRF‐1 protein expression compared to B6 and was suppressed by wheel running. Additionally, fasting induced muscle autophagy signaling and disrupted mitochondrial quality protein expression in the MIN, which was prevented in the MIN KO. We provide evidence that increased skeletal muscle AMPK sensitivity to a 12‐h fast is an adverse event in pre‐cachectic MIN mice, and exercise can improve this regulation. [ABSTRACT FROM AUTHOR]

Aim: Derangements in blood lipid and lipoprotein metabolism are one of the leading causes of coronary heart disease (CHD). Therapeutic lifestyle changes such as diet and exercise are often prescribed to improve blood lipid and lipoprotein characteristics, but the efficacy of a telephone‐based health coaching program has not been thoroughly explored. Our purpose was to examine effects of the Our Healthy Heart (OHH) Program on blood lipid and lipoprotein characteristics of individuals with mixed dyslipidaemia. Methods: Cholesterol content of serum very low‐density lipoprotein (VLDL), low‐density lipoprotein (LDL) and high‐density (HDL) subfractions and apolipoprotein concentrations were measured by vertical‐density ultracentrifugation (Vertical Auto Profile (VAP)) from 1522 individuals with mixed dyslipidaemia (age 18–99 years, body mass index (BMI) 25–40, 62.7% female). Telephone‐based health coaching (OHH, n = 722) or standard care (Control, n = 800) was provided for six months followed by VAP to evaluate changes in lipid and lipoprotein concentrations. Controls were obtained from individuals with similar blood lipid/lipoprotein characteristics who did not participate in the OHH Program. Coaches collected baseline self‐reported data on anthropometrics, food intake and exercise. Participants in the OHH group were then prescribed a hypocaloric 500 kcal/day caloric deficit with encouragement to participate in physical activity. A two‐way ANOVA was used to examine differences between groups over time, with results presented as means ± standard deviation. Results: Health coaching significantly decreased serum concentrations of apoB100 (104.5 ± 25.8–94.3 ± 24.8 mg/dL), shifted LDL pattern size from B to A or A/B in over 60% of the OHH group and decreased cholesterol content of all VLDL subfractions (P < 0.05) compared to the control. Conclusions: Telephone‐based health coaching recommendations to reduce dietary energy intake and increase physical activity produced significant improvements in cholesterol content of atherogenic lipoproteins, which are known to increase CHD risk. [ABSTRACT FROM AUTHOR]

Predicting the responsiveness to regular exercise is a topic of great relevance due to its potential role in personalized exercise medicine applications. The present review focuses on cardiorespiratory fitness (commonly measured by maximal oxygen uptake [ABSTRACT FROM AUTHOR]