Exercise Training Reduces Intrathoracic Fat Regardless of Defective Glucose Tolerance

Abstract

PurposeEpicardial (EAT) and pericardial (PAT) fat masses and myocardial triglyceride content (MTC) are enlarged in obesity and insulin resistance. We studied whether the high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) similarly decrease ectopic fat in and around the heart and whether the decrease is similar in healthy subjects and subjects with defective glucose tolerance (DGT).MethodsA total of 28 healthy men (body mass index = 20.7–30.0 kg·m−2, age = 40–55 yr) and 16 men with DGT (body mass index = 23.8–33.5 kg·m−2, age = 43–53 yr) were randomized into HIIT and MICT interventions for 2 wk. EAT and PAT were determined by computed tomography and MTC by 1H-MRS.ResultsAt baseline, DGT subjects had impaired aerobic capacity and insulin sensitivity and higher levels of whole body fat, visceral fat, PAT, and EAT (P < 0.05, all) compared with healthy subjects. In the whole group, HIIT increased aerobic capacity (HIIT = 6%, MICT = 0.3%; time × training P = 0.007) and tended to improve insulin sensitivity (HIIT = 24%, MICT = 8%) as well as reduce MTC (HIIT = −42%, MICT = +23%) (time × training P = 0.06, both) more efficiently compared with MICT, and without differences in the training response between the healthy and the DGT subjects. However, both training modes decreased EAT (−5%) and PAT (−6%) fat (time P < 0.05) and not differently between the healthy and the DGT subjects.ConclusionWhole body fat, visceral fat, PAT, and EAT masses are enlarged in DGT. Both HIIT and MICT effectively reduce EAT and PAT in healthy and DGT subjects, whereas HIIT seems to be superior as regards improving aerobic capacity, whole-body insulin sensitivity, and MTC.

Exercise training decreases pancreatic fat content and improves beta cell function regardless of baseline glucose tolerance: a randomised controlled trial

“…We have previously published several reports of the study focusing on different tissues [23–31]. The first phase of the study investigated healthy men (with measurements between March 2011 and February 2013), and the second phase involved men and women with type 2 diabetes or prediabetes (with measurements between February 2013 and October 2015).…”

“…This study was a parallel-group randomised controlled trial conducted at Turku PET Centre (Turku, Finland) as a part of a larger study entitled The Effects of Short-time High-intensity Interval Training on Tissue Glucose and Fat Metabolism in Healthy Subjects and Patients With Type 2 Diabetes (NCT01344928). We have previously published several reports of the study focusing on different tissues [ 23 – 31 ]. The first phase of the study investigated healthy men (with measurements between March 2011 and February 2013), and the second phase involved men and women with type 2 diabetes or prediabetes (with measurements between February 2013 and October 2015).…”

“…Randomisation to the SIT and MICT groups using a 1:1 allocation ratio was performed separately for the healthy and prediabetic or type 2 diabetic participants with random permuted blocks, as previously described in detail [ 23 , 27 , 28 ]. Given the nature of the intervention, no blinding was used.…”

“…The aims of the present study were to investigate (1) whether 2 weeks of exercise training would have similar effects on pancreatic fat content and beta cell function in healthy and prediabetic or type 2 diabetic men, and (2) whether the effects of sprint interval training (SIT) and MICT would differ in prediabetic or type 2 diabetic men and women. We previously showed that 2 weeks of either SIT or MICT decreased intrathoracic fat in both healthy and prediabetic or type 2 diabetic men [ 23 ]. We therefore hypothesised that pancreatic fat would decrease by exercise training similarly in healthy and prediabetic or type 2 diabetic participants.…”

The role of exercise in atrial fibrillation prevention and promotion: Finding optimal ranges for health

“…Indeed, in heart failure patients, exercise training reduces sympathetic activation (39). In addition to these potential mechanisms, there is a positive benefit of exercise on other AF-specific risk factors, including pericardial fat,(40) andM A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPTobstructive sleep apnea (41). It is likely that a reduction of AF risk factors and favorable changes in mechanistic promoters of AF converge to provide an antiarrhythmic effect of regular exercise.Too much of a good thing?…”