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New research finds exercise time of day matters for metabolism - Levels

The range of metabolites detected in the various tissues was from 596 in the hypothalamus to 894 in the blood. Each tissue responded uniquely to exercise at each time point. For instance, in response to exercise, the hypothalamus had 17 metabolites change in the evening and 33 in the morning, whereas in the blood, 61 metabolites changed in the evening and 195 in the morning. Exercise altered more metabolites in the morning than evening in all tissues.

Study of 50,000 people finds brown fat may protect against numerous chronic diseases -- ScienceDaily

In collaboration with Heiko Schoder and Andreas Wibmer at Memorial Sloan Kettering, the researchers reviewed 130,000 PET scans from more than 52,000 patients, and found the presence of brown fat in nearly 10 percent of individuals. (Cohen notes that this figure is likely an underestimate because the patients had been instructed to avoid cold exposure, exercise, and caffeine, all of which are thought to increase brown fat activity). Several common and chronic diseases were less prevalent among people with detectable brown fat. For example, only 4.6 percent had type 2 diabetes, compared with 9.5 percent of people who did not have detectable brown fat. Similarly, 18.9 percent had abnormal cholesterol, compared to 22.2 percent in those without brown fat.

Bursts of exercise can lead to significant improvements in indicators of metabolic health -- ScienceDaily

The MGH study drew on data from the Framingham Heart Study to measure the levels of 588 circulating metabolites before and immediately after 12 minutes of vigorous exercise in 411 middle-aged men and women. The research team detected favorable shifts in a number of metabolites for which resting levels were previously shown to be associated with cardiometabolic disease. For example, glutamate, a key metabolite linked to heart disease, diabetes and decreased longevity, fell by 29%. And DMGV, a metabolite associated with increased risk of diabetes and liver disease, dropped by 18%. The study further found that metabolic responses may be modulated by factors other than exercise, including a person's sex and body mass index, with obesity possibly conferring partial resistance to the benefits of exercise.

Morning exercise for optimal metabolic impact

They found that a protein called hypoxia-inducible factor 1-alpha (HIF-1α) plays an important role and that it is activated by exercise in different ways depending on the time of day. HIF-1α is a transcription factor that is known to stimulate certain genes based on oxygen levels in tissue. “It makes sense that HIF-1α would be important here, but until now we didn’t know that its levels fluctuate based on the time of day,” Sassone-Corsi says. “This is a new finding.” Based on the work from the UC Irvine team, exercise seemed to have the most beneficial impact on the metabolism at the beginning of the active phase phase (equivalent to late morning in humans) compared with the resting phase (evening).

Inactivity Induces Resistance to the Metabolic Benefits Following Acute Exercise. - PubMed - NCBI

METHODS: Ten untrained to recreationally active men (n=5) and women (n=5) completed a counterbalanced, crossover study. Four days of prolonged sitting without exercise (SIT) were compared to four days of prolonged sitting with a 1-hr bout of treadmill exercise (SIT+EX; 63.1±5.2% V̇O2max) on the evening of the fourth day. The following morning, participants completed a high fat/glucose tolerance test (HFGTT), during which plasma was collected over a 6-hr period and analyzed for triglycerides, glucose, and insulin. RESULTS: No differences between trials ( P > 0.05) were found in the overall plasma triglyceride, glucose, or insulin responses during the HFGTT. This lack of difference between trials comes with similarly low physical activity (~3,500-4,000 steps/day) on each day except for the 1-hr bout of exercise during SIT+EX the day before the HFGTT.

Glutamine metabolism affects T cell signaling and function -- ScienceDaily

In the current work, they turned their attention to another major fuel: glutamine, which has primarily been studied in the context of cancer cell metabolism. Several companies are developing drugs that inhibit glutamine metabolism to reduce cancer cell growth and proliferation. The investigators expected that inhibiting glutamine metabolism -- like blocking glucose metabolism -- would prevent T cell activation and function. They used a drug that inhibits the first step in glutamine metabolism, an enzyme called glutaminase. They also studied mice with targeted genetic deletion of the glutaminase gene. The researchers were surprised to find that certain T cells -- those that mediate antiviral and anticancer responses -- performed better in the absence of glutaminase activity. Other T cells involved in inflammatory and autoimmune diseases performed worse. "We were intrigued that one metabolic perturbation could have a very different impact on the function of subsets of T cells," said Marc Johnson, a graduate student who led the studies.

Insulin gives an extra boost to the immune system -- ScienceDaily

"We have identified one of metabolism's most popular hormones, specifically the insulin signaling pathway, as a novel 'co-stimulatory' driver of immune system function," says Dr. Dan Winer, who is also Assistant Professor, Department of Laboratory Medicine and Pathobiology at University of Toronto. "Our work characterizes the role of this signaling pathway in immune cells, mainly T cells, opening up avenues in the future to better regulate the immune system."

How do muscles know what time it is? -- ScienceDaily

In collaboration with Italian and Austrian colleagues (from the Venetian Institute of Molecular Medicine and the Universities of Padua, Graz, and Trieste) the researchers identified certain processes that are switched on at night by the regulators of the internal clock: "They include, for example, fat storage, glucose metabolism and insulin sensitivity," explains Henriette Uhlenhaut. At the same time, opposing processes such as fatty acid oxidation and protein breakdown are throttled down, according the authors. These patterns are especially pronounced in the hours before awakening and are thought to prepare the muscles for the day ahead. In the final step, the scientists investigated possible ways to intervene in these processes. To this end, they examined mice lacking these master regulators. Without a circadian clock, the animals were leaner, with less fat and more muscle mass. "Taken together, our work has revealed an entire metabolic network at multiple levels," Uhlenhaut explains. "Another biologically exciting finding is that, contrary to expectations, the key regulator is not centrally located in the brain, but is in fact the internal clock of the muscle cells themselves." In the long term, the authors will investigate the mechanisms also in humans and try to find a way for therapeutic interventions. Their hope is that it might be possible to counteract insulin resistance in type 2 diabetes or to stimulate energy use to combat obesity.

New research suggests evolution might favor 'survival of the laziest'

"We wondered, 'Could you look at the probability of extinction of a species based on energy uptake by an organism?'" said Luke Strotz, postdoctoral researcher at KU's Biodiversity Institute and Natural History Museum and lead author of the paper. "We found a difference for mollusk species that have gone extinct over the past 5 million years and ones that are still around today. Those that have gone extinct tend to have higher metabolic rates than those that are still living. Those that have lower energy maintenance requirements seem more likely to survive than those organisms with higher metabolic rates."

Anti-aging protein alpha Klotho's molecular structure revealed -- ScienceDaily

One of the major, paradigm-changing findings revealed by solving the protein complex structure is that the circulating form of soluble a-Klotho can actually serve as a co-receptor for FGF23. Thus, the soluble form of a-Klotho can go to any cell in the body and act as a co-receptor for FGF23, rendering every cell a possible target of FGF23, representing a major paradigm shift. "a-Klotho researchers in cancer, aging, neurologic, cardiovascular, and kidney disease will benefit from this research," Dr. Moe said. "The knowledge of the structure of the protein, along with its molecular binding partners, will enable us to greatly advance the understanding of how a-Klotho works and also how to best design therapeutic strategies and novel agents that can either activate or block FGF23-a-Klotho interaction and signaling as needed."

Hiking for a month transforms dude's metabolism

The question I had before my thru-hike was this: Would walking all day, every day, for a month improve my metabolic efficiency when I run at a high intensity? In other words, could I become a better athlete by simply walking?  Before the trip, I was burning 66 percent fat and 34 percent carbs during low-intensity exercise or any activity during which I had a heart rate of 112 bpm. At a slow long-run pace, with a heart rate of 145 bpm, I was burning 52 percent fat and 48 percent carbohydrates. My crossover point—the heart rate at which I was burning carbs and fat equally—was 153 bpm, or a moderate-to-slow running pace.  After the trip, I was, as my test administrator at Real Rehab in Seattle put it, “a fat-burning machine.” At 110 bpm, I was burning 91 percent fat and 9 percent carbohydrates. At 145 bpm, I was burning 70 percent fat and 30 percent carbohydrates. My crossover point had moved to 168 bpm, which I reached at a fairly fast running pace. And even at my maximum heart rate (184 bpm), I was still getting a quarter of my energy from fat.   What does this mean? I can now go on long runs without consuming gels and other foods, or at least a significantly reduced amount. Also, the next time I go backpacking, I will be able to carry less weight in my pack because each gram of fat has nine calories, while a gram of carbohydrate or protein provides less than half that energy—around four calories. This means I can carry more high-fat foods like nuts and cheese, while cutting way back on sugary high-carb snacks like energy bars and candy. Plus, if I run low on food near the end of a trip (something that happened several times between resupplies during our thru-hike), my body will be able to run just fine on body fat until I make it to the next rest stop.

Research has found that walking for two hours a day could cut inches off your waistline | UK | News | Daily Express

Replacing sitting for two hours a day with standing led to an 11 per cent lower BMI on average and a three-inch smaller waist. Average blood sugar levels also fell by 11 per cent. Dr Healy said: "These findings provide important preliminary evidence that strategies to increase the amount of time spent standing or walking rather than sitting may benefit the heart and metabolism of many people.