Leisure-time physical activity from adolescence to late middle age and its associations with the COVID-19 pandemic: A 45-year follow-up.

We aimed to investigate the association of self-reported leisure-time physical activity (LTPA) over a 45-years from adolescence to late middle age mediated by LTPA in early middle age. We also explored whether LTPA in adolescence and early middle age was associated with change in LTPA during the COVID-19 pandemic. We constructed a path model employing questionnaire data from three LTPA measurements (1976, 2001, 2021) including duplicated assessment for pre- and during COVID-19 in 2021. The direct and indirect associations between LTPA in adolescence, early middle and late middle age were investigated, as well as the impact of previous LTPA on change in late middle age LTPA due to the pandemic. The number of participants per assessment was: n = 2083; n = 1468 (71% of the original); n = 878 (42%) and n = 867 (42%), respectively. However, the number varied depending on the path examined. LTPA in adolescence was associated with LTPA in late middle age, although the association was not strong. LTPA decreased significantly during the pandemic. Earlier LTPA was associated with change in LTPA between before and during COVID-19 among males. This study is the first to demonstrate an association between adolescent and late middle age LTPA. However, the association across the 45-years was low.

Associations of resting and peak fat oxidation with sex hormone profile and blood glucose control in middle-aged women.

BACKGROUND AND AIMS: Menopause may reduce fat oxidation. We investigated whether sex hormone profile explains resting fat oxidation (RFO) or peak fat oxidation (PFO) during incremental cycling in middle-aged women. Secondarily, we studied associations of RFO and PFO with glucose regulation. METHOD AND RESULTS: We measured RFO and PFO of 42 women (age 52-58 years) with indirect calorimetry. Seven participants were pre- or perimenopausal, 26 were postmenopausal, and nine were postmenopausal hormone therapy users. Serum estradiol (E2), follicle-stimulating hormone, progesterone, and testosterone levels were quantified with immunoassays. Insulin sensitivity (Matsuda index) and glucose tolerance (area under the curve) were determined by glucose tolerance testing. Body composition was assessed with dual-energy X-ray absorptiometry; physical activity with self-report and accelerometry; and diet, with food diaries. Menopausal status or sex hormone levels were not associated with the fat oxidation outcomes. RFO determinants were fat mass (ß = 0.44, P = 0.006) and preceding energy intake (ß = -0.40, P = 0.019). Cardiorespiratory fitness (ß = 0.59, P = 0.002), lean mass (ß = 0.49, P = 0.002) and physical activity (self-reported ß = 0.37, P = 0.020; accelerometer-measured ß = 0.35, P = 0.024) explained PFO. RFO and PFO were not related to insulin sensitivity. Higher RFO was associated with poorer glucose tolerance (ß = 0.52, P = 0.002). CONCLUSION: Among studied middle-aged women, sex hormone profile did not explain RFO or PFO, and higher fat oxidation capacity did not indicate better glucose control.