Stimulating the brain makes exercising the legs feel easier
November 1, 2016
Science Daily/University of Kent
Stimulation of the brain impacts on endurance exercise performance by decreasing perception of effort, new research shows.
The study examined the effect of a technique called transcranial direct-current stimulation (tDCS), a form of non-invasive brain stimulation, on the neuromuscular, physiological and perceptual responses to exhaustive leg exercise.
Researchers led by Dr Lex Mauger from Kent's School of Sport and Exercise Sciences found that tDCS delayed exhaustion of the leg muscles by an average of 15% during an exercise task, and that this was likely caused by the participants feeling less effort during the exercise. However, tDCS elicited no significant effect on the neuromuscular response to exercise.
The performance effects of tDCS only occurred when the tDCS electrodes used to deliver the electrical current were positioned in a particular way. This study therefore provides important methodological guidance for the application of tDCS and provides further evidence that brain stimulation can improve endurance exercise performance, although the authors warn against the uncontrolled use of tDCS.
'Transcranial direct current stimulation improves isometric time to exhaustion of the knee extensors' (A. R. Mauger, L. Agnius, J. Hopker, S. M.Marcora, all University of Kent and B.Pageaux, Universite de Bourgogne) is published in the journal Neuroscience.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/11/161101133449.htm
Psychological well-being and physical activity in older adults
December 2, 2016
Science Daily/Chapman University
New findings showed associations between psychological well-being and physical activity in adults ages 50 and older.
"Researchers have long studied how physical activity can lead to improved mood and feelings of well-being," says Julia Boehm, Ph.D., and lead author on the study, "however, less well understood is whether being happy and optimistic might actually encourage a person to be physically active."
Physical activity is a key health behavior linked to better physical and mental functioning, as well as reduced risk of the leading causes of death including cancer and heart disease. Further, psychological well-being is associated with reduced risk of cardiovascular disease, cognitive decline, and mortality. Psychological well-being may be linked with improved health because happier people may be more likely to engage in physical activity.
Rates of physical activity are relatively low among middle-aged adults and decline further in older adulthood -- worsening substantially after age 75 -- so a key challenge is to identify not only modifiable factors that reduce the likelihood of declining activity levels, but also factors that contribute to the initiation and maintenance of physical activity in older age. Interventions that increase the number of people who are physically active may reduce the burden of poor health later in life.
"What we wanted to do in this study was to assess psychological well-being before assessing physical activity to determine if happier adults are more likely to exercise than their less happy peers," said Dr. Boehm.
During the 11-year study, participants were asked about the frequency and intensity of their physical activity both at work and during leisure time and then classified into categories of sedentary activity, low activity, moderate activity, and high activity.
The researchers found that higher psychological well-being at the start of the study was associated with greater levels of physical activity across more than a decade. Moreover, people at the start of the study who had high levels of psychological well-being and who were also physically active initially were less likely to become inactive over time.
"These findings have implications for health care as medical professionals often have difficulty persuading adults to increase physical activity," noted Dr. Boehm. "Results from this study suggest that higher levels of psychological well-being may precede increased physical activity; therefore, it is possible that psychological well-being could be a novel way of not only enhancing psychological health but also increasing physical activity -- which in turn could improve the physical health of a large segment of people in an aging society."
The study included 9,986 English adults over the age of 50 who were assessed up to six times across an average of 11 years. The average age of participants was 63.7 years, with 55 percent of participants being women, and 97 percent of the sample identifying as White.
The paper, called Maintaining Healthy Behavior: a Prospective Study of Psychological Well-Being and Physical Activity, is published in the journal Annals of Behavioral Medicine. Authors were: Dr. Julia Boehm of Chapman University; Eric Kim, Ph.D., Laura Kubzansky, Ph.D, and Jackie Soo, Ph.D., all of Harvard T. H. Chan School of Public Health.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/12/161202101114.htm
The loneliness of the individual athlete
December 12, 2016
Science Daily/British Psychological Society (BPS)
Athletes in individual sports are more prone to developing depressive symptoms than athletes in team sports.
That is one of the findings being presented today, Monday 12 December 2016, to the annual conference of the British Psychological Society's Division of Sport and Exercise Psychology in Cardiff by Professor Juergen Beckmann from the Technical University of Munich.
In his research on burnout and depression, Professor Beckmann and his team surveyed 162 elite and 199 junior elite athletes in two cross-sectional studies. They also conducted a longitudinal study of 85 junior athletes, surveying them three times over the course of a year.
These three studies were complemented by a qualitative study, in which 134 elite athletes were interviewed about perceived causes of their experienced stress, drop-out intentions and depressive symptoms.
The two cross-sectional studies found that sport-specific stress combined with insufficient time for recovery was associated with symptoms of depression. They also found that athletes in individual sports showed significantly higher scores for depressive symptoms than athletes in team sports.
The longitudinal study found that dysfunctional attitudes in athletes and a resigned coping style both predicted higher rates of depressive symptoms and burnout.
Although burnout and depression were significantly correlated, perfectionism and chronic stress predicted burnout but not depression. Depression was linked with a lack of time to recover from stress.
Professor Beckmann says: "Our research suggests that depression is particularly high in young athletes, with athletes in individual sports being more vulnerable. In Germany, we have developed a burnout and screening instrument for junior athletes and a website to give them advice on coping with stress and other psychological problems they may experience."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/12/161212084649.htm
Want to improve your memory? Go to the gym
December 13, 2016
Science Daily/British Psychological Society (BPS)
Exercise improves your short-term memory, new research concludes. In two experiments, healthy and active participants were given lists of words to learn and recall either after or before exercise, or before or after a period of rest. Exercise consisted of 30 minutes of moderate intensity cycling.
That is the conclusion of research being presented at the annual conference of the British Psychological Society's Division of Sport and Exercise Psychology in Cardiff by Dr David Marchant from Edge Hill University, Lancashire.
In two experiments, healthy and active participants were given lists of words to learn and recall either after or before exercise, or before or after a period of rest. Exercise consisted of 30 minutes of moderate intensity cycling.
The results showed that, when recalling the words immediately after learning, exercising before learning produced the best results than rest. When asked to wait 30 minutes between learning and recall, exercising before or after learning was better than resting, but the best recall was when participants exercised after learning the words.
Dr Marchant says: "Our research suggests that an acute bout of aerobic exercise improves your short-term memory. Exercise before learning benefited immediate recall. But when people had to wait to recall the words, they performed best when they exercised after learning the lists. This improved memory didn't come at the expense of making more mistakes during remembering.
"Our findings are consistent with the idea that physical arousal improves memory, and those who need to learn information may benefit from taking part in exercise."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/12/161213074341.htm
Jet lag impairs performance of major league baseball players
January 23, 2017
Science Daily/Northwestern University
A new study of how jet lag affects Major League Baseball players traveling across just a few time zones found that when players travel in a way that misaligns their internal 24-hour clock with the natural environment and its cycle of sunlight, they suffer negative consequences.
The researchers found that when people, in this case Major League Baseball players, travel in a way that misaligns their internal 24-hour clock with the natural environment and its cycle of sunlight, they suffer negative consequences.
"Jet lag does impair the performance of Major League Baseball players," said Dr. Ravi Allada, a circadian rhythms expert who led the study. "The negative effects of jet lag we found are subtle, but they are detectable and significant. And they happen on both offense and defense and for both home and away teams, often in surprising ways."
In a study of data spanning 20 years and including more than 40,000 games, the researchers identified these effects of jet lag on player and team performance:
• The offense of jet-lagged home teams is much more affected than that of jet-lagged away teams. Surprisingly, in terms of offensive performance, jet lag from eastward travel had significant negative effects on home teams (after returning from a road trip) and much less of an effect on away teams.
• Negative effects on offense are related to base running. The negative effects on the home team's offense were related to base running, such as stolen bases, number of doubles and triples, and hitting into more double plays.
• Both home and away teams suffer on defense, specifically by giving up more home runs. With defensive performance, strong effects of eastward jet lag were found for both home and away teams, primarily with jet-lagged pitchers allowing more home runs. "The effects are sufficiently large to erase the home field advantage," Allada said. Besides home runs allowed, few other effects were seen on pitching or defense.
• There is a difference between traveling east and traveling west. Most significant jet-lag effects were generally stronger for eastward than westward travel. "This is a strong argument that the effect is due to the circadian clock, not the travel itself," Allada said.
The study, "How Jet Lag Impairs Major League Baseball Performance," will be published the week of Jan. 23 in the journal Proceedings of the National Academy of Sciences (PNAS).
Allada and his team, Alex Song (first author) and Thomas Severini, used an unprecedented amount of MLB data (from 1992 to 2011), which gave the researchers the statistical power to identify the effects of jet lag on offensive and defensive performance metrics. The researchers considered if teams were traveling east or west; if the team was home or away; and the team itself.
They also looked at the number of hours players would be jet-lagged, based on the number of time zones traveled across, to determine which games were "jet-lag games" and which were not. (The human body clock can roughly shift about an hour each day as it synchronizes to the new environment.) If players were shifted two or three hours from their internal clocks, the researchers defined them as jet-lagged.
What does all this data analysis mean going forward? With MLB spring training less than a month away, Allada has some advice based on his research.
"If I were a baseball manager and my team was traveling across time zones -- either to home or away -- I would send my first starting pitcher a day or two ahead, so he could adjust his clock to the local environment," Allada said.
Allada provides an example from the 2016 National League Championship Series illustrating the potential impact of jet lag on player performance. In game 2, Los Angeles Dodgers' ace Clayton Kershaw shut out the Chicago Cubs, giving up only two hits, but game 6 was a different story.
"For game 6, the teams had returned to Chicago from LA, and this time the Cubs scored five runs off of Kershaw, including two home runs," Allada said. "While it's speculation, our research would suggest that jet lag was a contributing factor in Kershaw's performance."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/01/170123153835.htm
Your brain on exercise
February 13, 2017
Science Daily/University of California - Santa Barbara
Psychologists have designed an experiment to investigate whether human vision is more sensitive during physical activity.
https://images.sciencedaily.com/2017/02/170213171459_1_540x360.jpg
Participants rode stationary bikes while wearing a wireless heart rate monitor and an EEG cap.
Credit: Image courtesy of University of California - Santa Barbara
It's universally accepted that the benefits of exercise go well beyond fitness, from reducing the risk of disease to improving sleep and enhancing mood. Physical activity gives cognitive function a boost as well as fortifying memory and safeguarding thinking skills.
But can it enhance your vision? It appears so.
Intrigued by recent findings that neuron firing rates in the regions of mouse and fly brains associated with visual processing increase during physical activity, UC Santa Barbara psychologists Barry Giesbrecht and Tom Bullock wanted to know if the same might be true for the human brain.
To find out, they designed an experiment using behavioral measures and neuroimaging techniques to explore the ways in which brief bouts of physical exercise impact human performance and underlying neural activity. The researchers found that low-intensity exercise boosted activation in the visual cortex, the part of the cerebral cortex that plays an important role in processing visual information. Their results appear in the Journal of Cognitive Neuroscience.
"We show that the increased activation -- what we call arousal -- changes how information is represented, and it's much more selective," said co-author Giesbrecht, a professor in UCSB's Department of Psychological and Brain Sciences. "That's important to understand because how that information then gets used could potentially be different.
"There's an interesting cross-species link that shows these effects of arousal might have similar consequences for how visual information is processed," he continued. "That implies the evolution of something that might provide a competitive advantage in some way."
To investigate how exercise affects different aspects of cognitive function, the investigators enlisted 18 volunteers. Each of them wore a wireless heart rate monitor and an EEG (electroencephalogram) cap containing 64 scalp electrodes. While on a stationary bicycle, participants performed a simple orientation discrimination task using high-contrast stimuli composed of alternating black and white bars presented at one of nine spatial orientations. The tasks were performed while at rest and during bouts of both low- and high-intensity exercise.
The scientists then fed the recorded brain data into a computational model that allowed them to estimate the responses of the neurons in the visual cortex activated by the visual stimuli. They analyzed the responses while participants were at rest and then during low- and high-intensity exercise.
This approach allowed them to reconstruct what large populations of neurons in the visual cortex were doing in relation to each of the different stimulus orientations. The researchers were able to generate a "tuning curve," which estimates how well the neurons are representing the different stimulus orientations.
"We found that the peak response is enhanced during low-intensity exercise relative to rest and high-intensity exercise," said lead author Bullock, a postdoctoral researcher in UCSB's Attention Lab. "We also found that the curve narrows in, which suggests a reduction in bandwidth. Together, the increased gain and reduced bandwidth suggest that these neurons are becoming more sensitive to the stimuli presented during the low-intensity exercise condition relative to the other conditions."
Giesbrecht noted that they don't know the mechanism by which this is occurring. "There are some hints that it may be driven by specific neurotransmitters that increase global cortical excitability and that can account for the change in the gain and the increase in the peak response of these tuning profiles," he said.
From a broader perspective, this work underscores the importance of exercise. "In fact, the benefits of brief bouts of exercise might provide a better and more tractable way to influence information processing -- versus, say, brain training games or meditation -- and in a way that's not tied to a particular task," Giesbrecht concluded.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/02/170213171459.htm
With beetroot juice before exercise, aging brains look 'younger'
April 19, 2017
Science Daily/Wake Forest University
Drinking a beetroot juice supplement before working out makes the brain of older adults perform more efficiently, mirroring the operations of a younger brain, according to a new study.
"We knew, going in, that a number of studies had shown that exercise has positive effects on the brain," said W. Jack Rejeski, study co-author. "But what we showed in this brief training study of hypertensive older adults was that, as compared to exercise alone, adding a beet root juice supplement to exercise resulted in brain connectivity that closely resembles what you see in younger adults."
While continued work in this area is needed to replicate and extend these exciting findings, they do suggest that what we eat as we age could be critically important to the maintenance of our brain health and functional independence.
Rejeski is Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science. The study, "Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain," was published in the peer-reviewed Journals of Gerontology: Medical Sciences. One of his former undergraduate students, Meredith Petrie, was the lead author on the paper.
This is the first experiment to test the combined effects of exercise and beetroot juice on functional brain networks in the motor cortex and secondary connections between the motor cortex and the insula, which support mobility, Rejeski said.
The study included 26 men and women age 55 and older who did not exercise, had high blood pressure, and took no more than two medications for high blood pressure. Three times a week for six weeks, they drank a beetroot juice supplement called Beet-It Sport Shot one hour before a moderately intense, 50-minute walk on a treadmill. Half the participants received Beet-It containing 560 mg of nitrate; the others received a placebo Beet-It with very little nitrate.
Beets contain a high level of dietary nitrate, which is converted to nitrite and then nitric oxide (NO) when consumed. NO increases blood flow in the body, and multiple studies have shown it can improve exercise performance in people of various ages.
"Nitric oxide is a really powerful molecule. It goes to the areas of the body which are hypoxic, or needing oxygen, and the brain is a heavy feeder of oxygen in your body," said Rejeski.
When you exercise, the brain's somatomotor cortex, which processes information from the muscles, sorts out the cues coming in from the body. Exercise should strengthen the somatomotor cortex.
So, combining beetroot juice with exercise delivers even more oxygen to the brain and creates an excellent environment for strengthening the somatomotor cortex. Post-exercise analysis showed that, although the study groups has similar levels of nitrate and nitrite in the blood before drinking the juice, the beetroot juice group had much higher levels of nitrate and nitrite than the placebo group after exercise.
https://www.sciencedaily.com/releases/2017/04/170419091619.htm
How walking benefits the brain
Researchers show that foot's impact helps control, increase the amount of blood sent to the brain
April 24, 2017
Science Daily/Experimental Biology 2017
You probably know that walking does your body good, but it's not just your heart and muscles that benefit. Researchers found that the foot's impact during walking sends pressure waves through the arteries that significantly modify and can increase the supply of blood to the brain.
Until recently, the blood supply to the brain (cerebral blood flow or CBF) was thought to be involuntarily regulated by the body and relatively unaffected by changes in the blood pressure caused by exercise or exertion. The NMHU research team and others previously found that the foot's impact during running (4-5 G-forces) caused significant impact-related retrograde (backward-flowing) waves through the arteries that sync with the heart rate and stride rate to dynamically regulate blood circulation to the brain.
In the current study, the research team used non-invasive ultrasound to measure internal carotid artery blood velocity waves and arterial diameters to calculate hemispheric CBF to both sides of the brain of 12 healthy young adults during standing upright rest and steady walking (1 meter/second). The researchers found that though there is lighter foot impact associated with walking compared with running, walking still produces larger pressure waves in the body that significantly increase blood flow to the brain. While the effects of walking on CBF were less dramatic than those caused by running, they were greater than the effects seen during cycling, which involves no foot impact at all.
"New data now strongly suggest that brain blood flow is very dynamic and depends directly on cyclic aortic pressures that interact with retrograde pressure pulses from foot impacts," the researchers wrote. "There is a continuum of hemodynamic effects on human brain blood flow within pedaling, walking and running. Speculatively, these activities may optimize brain perfusion, function, and overall sense of wellbeing during exercise."
"What is surprising is that it took so long for us to finally measure these obvious hydraulic effects on cerebral blood flow," first author Ernest Greene explained. "There is an optimizing rhythm between brain blood flow and ambulating. Stride rates and their foot impacts are within the range of our normal heart rates (about 120/minute) when we are briskly moving along."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/04/170424141340.htm
Aerobic, resistance exercise combo can boost brain power of over 50s
Effects independent of current state of brain health, finds evidence review
April 24, 2017
Science Daily/BMJ
A combination of aerobic and resistance exercises can significantly boost the brain power of the over 50s, finds the most comprehensive review of the available evidence to date.
And the effects were evident irrespective of the current state of an individual's brain health, the analysis shows.
Physical exercise for older adults is seen as a promising means of warding off or halting a decline in brain health and cognitive abilities. Yet the evidence for its benefits is inconclusive, largely because of overly restrictive inclusion criteria in the reviews published to date, say the researchers.
In a bid to try and plug some of these gaps, they systematically reviewed 39 relevant studies published up to the end of 2016 to assess the potential impact of varying types, intensities, and durations of exercise on the brain health of the over 50s.
They included aerobic exercise; resistance training (such as weights); multi-component exercise, which contains elements of both aerobic and resistance training; tai chi; and yoga in their analysis.
They analysed the potential impact of these activities on overall brain capacity (global cognition); attention (sustained alertness, including the ability to process information rapidly); executive function (processes responsible for goal oriented behaviours); memory (storage and retrieval); and working memory (short term application of found information).
Pooled analysis of the data showed that exercise improves the brain power of the over 50s, irrespective of the current state of their brain health.
Aerobic exercise significantly enhanced cognitive abilities while resistance training had a pronounced effect on executive function, memory, and working memory.
The evidence is strong enough to recommend prescribing both types of exercise to improve brain health in the over 50s, say the researchers.
The data showed that tai chi also improved cognitive abilities, which backs the findings of previously published studies, but the analysis was based on just a few studies, caution the researchers, so will need to be confirmed in a large clinical trial.
Nevertheless, it's an important finding, they suggest, because exercises like tai chi may be suitable for people who are unable to do more challenging forms of physical activity.
And in terms of how much and how often, the data analysis showed that a session lasting between 45 and 60 minutes, of moderate to vigorous intensity, and of any frequency, was good for brain health.
The researchers point to some potential limitations of their review: their evidence was confined only to studies of supervised exercise and which had been published in English.
Nevertheless, they conclude: "The findings suggest that an exercise programme with components of both aerobic and resistance type training, of at least moderate intensity and at least 45 minutes per session, on as many days of the week as possible, is beneficial to cognitive function in adults aged over 50."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/04/170424215441.htm
Exercising can protect the brain from Alzheimer's disease
May 16, 2017
Science Daily/University of British Columbia Okanagan campus
The evidence is clear. Physical activity is associated with a reduced risk of Alzheimer's disease, a new study concludes.
The evidence is clear. Physical activity is associated with a reduced risk of Alzheimer's disease, says a panel of researchers and not-for-profit leaders, led by UBC's Okanagan campus.
The researchers also confirmed that regular physical activity may improve the performance of daily activities for people afflicted with Alzheimer's. Their conclusions may have significant implications for the 1.1 million Canadians affected directly or indirectly by dementia.
"As there is no current cure for Alzheimer's, there is an urgent need for interventions to reduce the risk of developing it and to help manage the symptoms," says study first author Kathleen Martin Ginis, professor in UBC Okanagan's School of Health and Exercise Sciences. "After evaluating all the research available, our panel agrees that physical activity is a practical, economical and accessible intervention for both the prevention and management of Alzheimer's disease and other dementias."
Martin Ginis and her cohort reviewed data from more than 150 research articles about the impact of physical activity on people with Alzheimer's. Some of the work explored how physical activity improves the patient's quality of life and the others examined the risk of developing Alzheimer's based on the amount of activity in which an individual participated.
The panel concluded that regular physical activity improves activities of daily living and mobility in in older adults with Alzheimer's and may improve general cognition and balance. They also established that older adults not diagnosed with Alzheimer's who are physically active, were significantly less likely to develop the disease compared to people who were inactive.
"This is exciting work," says Martin Ginis. "From here we were able to prepare a consensus statement and messaging which not only has community backing, but is also evidence-based. Now we have the tool to promote the protective benefit of physical activity to older adults. I'm hopeful this will move the needle on this major health concern."
Alzheimer's disease is the most common form of dementia, characterized by progressive neurodegeneration that results in severe cognitive impairment, compromised physical ability and loss of independence. The number of worldwide cases is expected to increase from 30.8 million in 2010 to more than 106 million in 2050.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/05/170516124023.htm