BackgroundThe purpose of this study was to examine whether very short duration, very high intensity sprint interval training (SIT) leads to loss of body fat mass in association with improvements to VO2max and fatty acid oxidation, and to assess the extent of sex dimorphism in these physiological responses.MethodsA total of 24 men and 17 women (mean (SEM) age: 39 (±2) years; body mass index 24.6 (0.6)) completed measurements of the maximal rate of oxygen uptake (VO2max) and fatty acid oxidation (FATmax). Body fat and lean mass were measured by dual emission x-ray absorptiometry, and fasting blood lipid, glucose and insulin profiles were assessed before and after training. SIT consisted of 4×20 s sprints on a cycle ergometer at approximately 175% VO2max, three times per week for 12 weeks.ResultsFat mass decreased by 1.0 kg, although men lost statistically significantly more fat than women both when expressed in Kg and as % body fat. VO2max increased by around 9%, but women improved VO2max significantly more than men. FATmax improved by around 13%, but fasting plasma glucose, insulin, total triglyceride, total cholesterol and high-density lipoprotein (HDL) did not change after training, while low-density lipoprotein decreased by 8% (p=0.028) and the HDL:Total Cholesterol ratio improved by 6%. There were no sex differences in these metabolic responses to training.ConclusionsThese results show lower body fat %, and higher rates of fatty acid oxidation and VO2max after 12 weeks of training for just 4 min per week. Notably, women improved VO2max more than men, while men lost more fat than women.

Introductioncognitive deterioration and reductions of bone health coincide with increasing age. We examine the relationship between bone composition and plasma markers of bone remodelling with measures of cognitive performance in healthy adults.Methodsthis cross-sectional study included 225 old (52% women, mean age: 74.4 ± 3.3 years) and 134 young (52% women, mean age: 23.4 ± 2.7 years) adult participants from the MyoAge project. Whole body bone mineral density was measured by dual-energy X-ray absorptiometry. Blood analyses included a panel of bone-related peptides (dickkopf-1, osteoprotegerin, osteocalcin (OC), osteopontin, sclerostin, parathyroid hormone and fibroblast growth factor 23), as well as serum calcium and 25-hydroxy vitamin D assays. A selection of cognitive domains (working memory capacity, episodic memory, executive functioning and global cognition) was assessed with a standardised neuropsychological test battery.Resultsadjusting for covariates and multiple testing revealed that plasma OC levels were positively associated with measures of executive functioning (β = 0.444, P < 0.001) and global cognition (β = 0.381, P = 0.001) in the older women.Discussionthese correlative results demonstrate a positive association between OC, a factor known to regulate bone remodelling, with cognitive performance in older non-demented women. Further work should address possible mechanistic interpretations in humans.

Chronic low-grade inflammation during aging (inflammaging) is associated with cognitive decline and neurodegeneration; however, the mechanisms underlying inflammaging are unclear. We studied a population (n = 361) of healthy young and old adults from the MyoAge cohort. Peripheral levels of C-X-C motif chemokine ligand 10 (CXCL10) was found to be higher in older adults, compared with young, and negatively associated with working memory performance. This coincided with an age-related reduction in blood DNA methylation at specific CpGs within the CXCL10 gene promoter. In vitro analysis supported the role of DNA methylation in regulating CXCL10 transcription. A polymorphism (rs56061981) that altered methylation at one of these CpG sites further associated with working memory performance in 2 independent aging cohorts. Studying prefrontal cortex samples, we found higher CXCL10 protein levels in those with Alzheimer's disease, compared with aged controls. These findings support the association of peripheral inflammation, as demonstrated by CXCL10, in aging and cognitive decline. We reveal age-related epigenetic and genetic factors which contribute to the dysregulation of CXCL10.

Lower physical activity levels in old age are thought to contribute to the age‐related decline in peak aerobic and anaerobic power. Master athletes maintain high levels of physical activity with advancing age and endurance or power training may influence the extent to which these physical functions decline with advancing age. To investigate, 37‐90‐year‐old power (n = 20, 45% female) and endurance (n = 19, 58% female) master athletes were recruited. Maximal aerobic power was assessed when cycling two‐legged (VO2Peak2‐leg) and cycling one‐legged (VO2Peak1‐leg), while peak jumping (anaerobic) power was assessed by a countermovement jump. Men and women had a similar VO2Peak2‐leg (mL/kg/min, P = 0.138) and similar ratio of VO2Peak1‐leg to VO2Peak2‐leg (P = 0.959) and similar ratio of peak aerobic to anaerobic power (P = 0.261). The VO2Peak2‐leg (mL/kg/min) was 17% (P = 0.022) and the peak rate of fat oxidation (FATmax) during steady‐state cycling was 45% higher in endurance than power athletes (P = 0.001). The anaerobic power was 33% higher in power than endurance athletes (P = 0.022). The VO2Peak1‐leg:VO2Peak2‐leg ratio did not differ significantly between disciplines, but the aerobic to anaerobic power ratio was 40% higher in endurance than power athletes (P = 0.002). Anaerobic power, VO2Peak2‐leg, VO2Peak1‐leg, and power at FATmax decreased by around 7%‐14% per decade in male and female power and endurance athletes. The cross‐sectional data from 37‐90‐year‐old master athletes in the present study indicate that peak anaerobic and aerobic power decline by around 7%‐14% per decade and this does not differ between athletic disciplines or sexes.

Summary 5Bone mineral density declines with increasing older age. We examined the levels of 6 circulating factors known to regulate bone metabolism in healthy young and older adults. The circulating levels of dickkopf-1, osteocalcin, osteoprotegerin and sclerostin were 8 positively associated with WBMD in older adults, despite the average WBMD being lower 9 and circulating dickkopf-1, osteoprotegerin and sclerostin being higher in old than young.