A meta-analysis published in the British Journal of Sports Medicine has shown that isometric exercises, which involve contracting muscles to hold the body in position without moving such as in wall squats, are best for reducing resting blood pressure. The researchers reviewed 270 randomised clinical trials with a total of 15 827 participants.
All of the studies included measured blood pressure after two weeks or more of exercise intervention, and included non-intervention control groups. It was found that isometric exercises reduced systolic and diastolic blood pressure by 8.24 and 4.00mmHg respectively. The next most effective forms of training in reducing blood pressure were combined training, followed by dynamic resistance training, aerobic exercise, and high-intensity interval training (HIIT).
The researchers noted that current guidelines are based on older research and as such don’t include data from new forms of exercise such as HIIT. These guidelines tend to emphasise aerobic training such as running for controlling blood pressure. In addition to helping clinicians optimise individualised exercise recommendations, the new findings suggest that it might be time to update exercise guidelines for preventing and treating high blood pressure.
A safe treatment against Alzheimer’s progression may be hidden in a common bodybuilding supplement. Researchers recently discovered that a muscle-building supplement called beta-hydroxy beta-methylbutyrate (HMB), may help protect memory, reduce plaques and ultimately help prevent the progression of Alzheimer’s disease. The researchers published their results in the journal Cell Reports.
HMB is a safe over-the-counter supplement, which bodybuilders regularly use to enhance exercise-related muscle strength and growth.
“This may be one of the safest and the easiest approaches to halt disease progression and protect memory in Alzheimer’s disease patients,” said Kalipada Pahan, PhD, at RUSH Medical College.
Studies in mouse models of Alzheimer’s have shown that HMB successfully reduces plaques and increases factors for neuronal growth to protect learning and memory, according to neurological researchers at RUSH.
“Understanding how the disease works is important to developing effective drugs to protect the brain and stop the progression of Alzheimer’s disease,” Pahan said.
Previous studies indicate that a family of proteins known as neurotrophic factors are drastically decreased in the brains of people with Alzheimer’s disease and have been found to help in survival and function of neurons, which are cells that receive and send messages from the body to the brain and vice versa.
“Our study found that after oral consumption, HMB enters into the brain to increase these beneficial proteins, restore neuronal connections and improve memory and learning in mice with Alzheimer’s-like pathology, such as plaques and tangles,” Pahan said.
The study findings indicate that HMB stimulates the nuclear hormone receptor PPARα within the brain that regulates the transport of fatty acids, which is key to the success of HMB as a neuroprotective supplement.
“If mouse results with HMB are replicated in Alzheimer’s disease patients, it would open up a promising avenue of treatment of this devastating neurodegenerative disease,” Pahan said.
Researchers from Japan have developed a novel wearable chemical sensor capable of measuring the concentration of chloride ions in sweat. The technology, described in the journal ACS Sensors, uses a ‘heat-transfer printing’ technique, the proposed sensor can be applied to the outer surface of common textiles to prevent skin irritation and allergies, and could also be useful in the early detection of heat stroke and dehydration.
Advances in miniaturisation have led to science-fiction like technologies such as wearable sensors which are usually placed directly on the skin. They can monitor important bodily parameters, including heart rate, blood pressure, and muscle activity and are often incorporated into devices such as smart watches.
Some wearable sensors can also detect chemicals in bodily fluids. For instance, sweat biosensors can measure the concentration of ions in sweat, providing information on their levels in blood. However, designing such chemical sensors is more complex than physical sensors. Direct contact between a wearable chemical sensor and skin can cause irritation and allergies. In contrast, if the sensor is fabricated directly on a wearable textile, its accuracy decreases due to surface irregularities.
In a recent study, a research team, led by Associate Professor Isao Shitanda of the Tokyo University of Science (TUS) in Japan, has developed an innovative sweat biosensor that addresses the aforementioned problems. Their technique involves ‘heat-transfer printing’ to fix a thin, flexible chloride ion sensor onto a textile substrate.
“The proposed sensor can be transferred to fibre substrates, and thus can be incorporated into textiles such as T-shirts, wristbands, and insoles,” explains Dr Shitanda. “Further, health indicators such as chloride ion concentration in sweat can be measured by simply wearing them.”
The heat-transfer printing approach offers several advantages. For one thing, the sensor is transferred outside of the piece of clothing, which prevents skin irritation. In addition, the wicking effect of the textile helps spread the sweat evenly between the electrodes of the sensor, creating a stable electrical contact. Moreover, printing the sensor on a flat surface and then transferring it prevents the formation of blurred edges that commonly occur when printing directly onto a textile.
The researchers carefully selected non-allergenic materials and electrochemical mechanisms of the sensor. After developing the sensor, they conducted various experiments using artificial sweat to verify its accuracy in measuring chloride ion concentration. The change in the electromotive force of the sensor was −59.5 mTV/log CCl−. Additionally, it displayed a Nernst response and a linear relationship with the concentration range of chloride ions in human sweat. Moreover, no other ions or substances typically present in sweat were found to interfere with the measurements.
Lastly, the team tested the sensor on a volunteer who exercised on a static bicycle for 30 minutes, by measuring their perspiration rate, chloride ion levels in blood, and saliva osmolality every five minutes to compare with the data previously gathered by the sensor. The proposed wearable sensor could reliably measure the concentration of chloride ions in sweat.
The sensor can also transmit data wirelessly, making real-time health monitoring easier. “Since chloride is the most abundant electrolyte in human sweat, measuring its concentration provides an excellent indicator of the body’s electrolyte balance and a useful tool for the diagnosis and prevention of heat stroke,” remarks Dr Shitanda.
This research thus demonstrates the potential of using wearable ion sensors for the real-time monitoring of sweat biomarkers, facilitating personalised healthcare development and athlete training management.
Most athletes know that diet and training go hand in hand for the best results, and many of them closely monitor their energy intake and training. However, a new study from Aarhus University shows that the bodies of female athletes are negatively affected when they consume too little energy through their diet in comparison with their training volume, explains PhD student Mikkel Oxfeldt. He and Associate Professor Mette Hansen are behind the study, which is published in the Journal of Physiology.
“We know that both elite female athletes and active women at times, either consciously or unconsciously, don’t have an energy intake that matches their energy expenditure when training. The study shows that insufficient energy intake can negatively affect muscles’ ability to respond to training. After just ten days of low energy intake, we began seeing changes to the hormonal system such as a decrease in the metabolic hormone followed by a decrease in metabolism.”
The study shows that it is important that women are careful not to reduce their energy intake too much. In fact, they should actually be increasing their energy intake if they increase their training volume, says Mikkel Oxfeldt:
“When you don’t get enough energy from your diet, your body will begun to pare down processes that require a lot of energy, just like a mobile phone that goes into battery-saving mode. We know from previous studies that it can cause some women’s periods to stop. However, our results show that other processes in the body, such as building new muscle proteins, are also affected.”
We must confront the unilateral focus on weight
Thirty fit women aged 18–30 participated in the study which is part of the Novo Nordic-funded Team Denmark network called ‘competition preparation and training optimisation’. All the women started the study right after the start of their menstrual period and followed a very controlled training and diet regimen for three weeks.
“Under the supervision of the researchers, the participants carried out individual training programmes aimed at increasing muscle mass, strength and overall fitness. The women’s meals were also provided by us. By controlling their training regimen and their diets, we were able to see how much energy they expended and what they ate during the study,” says Mikkel Oxfeldt and continues:
“This is the first time that such a well-controlled study has been carried out in this area, where both the diet and training of a group of fit women has been regulated to this extent. During the study, all participants drank doubly labelled water, which is enriched with a trace material. When we combine this tracer technique with the retrieval and subsequent analysis of muscle tissue samples, we can gain detailed insight into the muscles’ response to the experimental protocol,” explains Mikkel Oxfeldt.
Mikkel and the research group believe it’s necessary to confront the idea that weight loss leads to medals when in fact weight loss can negatively impact a number of the body’s systems, including muscles.
“In recent years, we’ve heard about public weigh-ins within some elite sports. They are part of promoting a culture in which some women are constantly trying to lose weight. However, our results show that this focus on weight loss can have short and potentially long-term negative consequences for women, both in relation to their health and training results. The study will hopefully provide athletes and coaches with a more nuanced picture of possible side effects.”
In collaboration with colleagues from the University of Copenhagen and University of Southern Denmark, the researchers behind the study are now investigating how physical performance, the immune system and metabolism are affected by an insufficient energy intake. They hope to one day be able to establish whether there is a difference between how women’s and men’s bodies react to inadequate energy intake.
An analysis on the positive effects of exercise on blood sugar levels in people with Type 2 diabetes mellitus (T2DM) shows that while all exercise helps, certain activities – and their timing – are especially beneficial. The study, published in The American Journal of Medicine, provides a comprehensive but straightforward summary of the benefits of exercise on controlling blood glucose levels in people with T2DM.
“The challenge with this is that most, if not all, people know exercise is good for them but they don’t know the best approach,” said Steven Malin, an associate professor in the Department of Kinesiology and Health at the Rutgers School of Arts and Sciences and an author of the study. “We targeted this issue by focusing on a few key parameters: the utility of aerobics versus weightlifting, the time of day that is optimal for exercise, whether to exercise before or after meals and whether we have to lose weight to get benefits or not.”
As part of the analysis, researchers sifted through dozens of studies and extracted common conclusions. Some of the key findings include:
Habitual aerobic exercise: increases the heart rate and the body’s use of oxygen helps manage blood glucose.
Resistance exercise: benefits insulin sensitivity in those with Type 2 diabetes.
Movement throughout the day by breaking up sitting time benefits blood glucose control and insulin levels.
Performing exercise later in the day can result in better control of blood sugar levels as well as improve insulin sensitivity.
“In short, any movement is good and more is generally better,” Malin said. “The combination of aerobic exercise and weightlifting is likely better than either alone. Exercise in the afternoon might work better than exercise in the morning for glucose control, and exercise after a meal may help slightly more than before a meal. And, you don’t have to lose weight to see the benefits of exercise. That is because exercise can lower body fat and increase muscle mass.”
While insulin resistance in T2DM is harmful, scientists believe increased insulin sensitivity is beneficial. High insulin sensitivity allows the cells of the body to use blood glucose more effectively, reducing blood sugar.
Malin researches insulin sensitivity and teaches kinesiology, the study of human movement. He and several other faculty members at Rutgers support the concept of “exercise as medicine.” The idea, which is supported by the American College of Sports Medicine and is increasingly being borne out by research, is that exercise can be considered a first-line therapy.
“I’m one of those individuals who subscribes to that notion, and in that way, I think of exercise as a drug,” Malin said.
Malin and colleagues authored the study to offer the medical community up-to-date practical advice for their patients.
“Together, this idea of exercise timing and type is important because it helps medical professionals more accurately recommend exercise prescriptions to combat high blood glucose,” Malin said.
Pre-surgery exercise and education, or ‘prehabilitation’, can significantly improve outcomes for patients undergoing orthopaedic surgery, according to new research published in JAMA Network Open.
An ageing population plus the COVID pandemic has put great strains on healthcare systems, creating a longer waiting time for patients due to undergo routine elective surgical procedures. This can cause mental and physical deconditioning in patients, potentially impacting their surgical outcomes.
The study found prehabilitation may mitigate these negative factors and assist in improving strength and function prior to a surgical intervention. This may include exercise, patient education, pain management and psychological support.
Researchers from Anglia Ruskin University (ARU), Addenbrooke’s – Cambridge University Hospitals NHS Foundation Trust (CUH) and Western University in Ontario, Canada, examined the results of 48 unique clinical trials involving prehabilitation techniques such as exercise, pain management and acupuncture among patients about to undergo orthopaedic surgery.
Outcomes were measured prior to surgery as well as at intervals post-operation. Results were graded for certainty, or confidence that results were true.
Prior to surgery, the study found strong evidence that prehabilitation led to a reduction in back pain for people waiting for lower back surgery and evidence of moderate certainty for improvement in their health-related quality of life.
For patients waiting for total knee replacement, evidence of moderate certainty showed prehabilitation improved function and muscle strength. For patients waiting for a total hip replacement, evidence of moderate certainty showed prehabilitation improved health-related quality of life and hip muscle strength.
Following an operation, the study found that prehabilitation improved function in the short to medium term compared with no prehabilitation. In particular, evidence of moderate certainty suggested prehabilitation had favourable outcomes on function in those who had undergone knee replacement surgery at six weeks post-operatively. Evidence of moderate certainty also suggests prehabilitation improved function six months after lower back surgery.
Lead author Anuj Punnoose, ARU PhD candidate and Clinical Specialist Physiotherapist at CUH, said: “This study stemmed out of a need to find the best ways to prepare orthopaedic patients prior to surgery and prevent them from further deconditioning. Furthermore, any prehabilitation programme should ideally be delivered for at least four to six weeks prior to the surgical intervention and twice a week for optimum results. Health services looking at developing such programmes could utilise recommendations from this study.”
People with strong legs are less likely to develop heart failure after a heart attack, according to new research. Myocardial infarction is the most common cause of heart failure, with around 6–9% of heart attack patients going on to develop the condition. Previous research has shown that having strong quadriceps is associated with a lower risk of death in patients with coronary artery disease.
Presented at Heart Failure 2023, a scientific congress of the European Society of Cardiology (ESC), this study tested the hypothesis that leg strength is associated with a lower risk of developing heart failure after acute myocardial infarction. The study included 932 patients hospitalised in 2007 to 2020 with acute myocardial infarction who did not have heart failure prior to the admission and did not develop heart failure complications during their hospital stay. The median age was 66 years and 753 participants (81%) were men.
Maximal quadriceps strength was measured as an indicator of leg strength. Patients sat on a chair and contracted the quadriceps muscles as hard as possible for five seconds. A handheld dynamometer attached to the ankle recorded the maximum value in kg. The measurement was performed on each leg and the researchers used the average of both values. Strength was expressed relative to body weight, meaning that quadriceps strength in kg was divided by body weight in kg and multiplied by 100 for a % body weight value. Patients were classified as ‘high’ or ‘low’ strength according to whether their value was above or below the median for their se
The median value for women was 33% body weight and the median value for men was 52% body weight. A total of 451 patients had low quadriceps strength and 481 had high strength. During an average follow-up of 4.5 years, 67 patients (7.2%) developed heart failure. The incidence of heart failure was 10.2 per 1000 person-years in patients with high quadriceps strength and 22.9 per 1000 person-years in those with low strength.
The researchers analysed the association between quadriceps strength (low vs. high) and the risk of developing heart failure. The analysis was adjusted for factors known to be associated with the development of heart failure after myocardial infarction including age, sex, body mass index, prior myocardial infarction or angina pectoris, diabetes, atrial fibrillation, chronic obstructive pulmonary disease, peripheral arterial disease and kidney function. Compared with low quadriceps strength, a high strength level was associated with a 41% lower risk of developing heart failure (hazard ratio [HR]: 0.59; 95% confidence interval [CI] 0.35–1.00; p=0.048).
The investigators also analysed the association between quadriceps strength as a continuous variable and the risk of developing heart failure. Each 5% body weight increment in quadriceps strength was associated with an 11% lower likelihood of heart failure (HR 0.89; 95% CI 0.81–0.98; p=0.014).
Study author Mr. Kensuke Ueno, a physical therapist at the Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan said: “Quadriceps strength is easy and simple to measure accurately in clinical practice. Our study indicates that quadriceps strength could help to identify patients at a higher risk of developing heart failure after myocardial infarction who could then receive more intense surveillance. The findings need to be replicated in other studies, but they do suggest that strength training involving the quadriceps muscles should be recommended for patients who have experienced a heart attack to prevent heart failure.”
Regular physical activity and exercise may reduce bleeding in individuals with intracerebral haemorrhage, a University of Gothenburg study shows. The study, published in the journal Stroke and Vascular Neurology, analysed data on 686 people treated for intracerebral haemorrhage at Sahlgrenska University Hospital in Gothenburg during the years 2014 to 2019.
The study was a retrospective analysis and could not determine causation. Nonetheless, it was clear that those who reported regular physical activity had smaller haemorrhages than those who reported being inactive.
Physically active was defined as engaging in at least light physical activity, such as walking, cycling, swimming, gardening, or dancing, for at least four hours weekly.
50 percent less bleeding volume
The main author of the study is Adam Viktorisson, a PhD student in clinical neuroscience at Sahlgrenska Academy, University of Gothenburg, and doctor in general practice at Sahlgrenska University Hospital.
“We found that individuals who engage in regular physical activity had, on average, bleeding volumes that were 50 percent smaller upon arriving to the hospital. A similar connection has previously been seen in animal studies, but no prior study has demonstrated this in humans.”
Everyone who comes to the hospital with a suspected intracerebral haemorrhage undergoes a computerized tomography (CT) scan of the brain. Depending on the severity of the haemorrhage, neurosurgery may be required. However, in most cases, non-surgical methods and medications are used to manage symptoms and promote patient recovery.
Intracerebral haemorrhage is the most dangerous type of stroke and can lead to life-threatening conditions. The risk of severe consequences from the haemorrhage increases with the extent of the bleeding.
“In cases of major intracerebral haemorrhages, there is a risk of increased pressure within the skull that can potentially lead to fatal outcomes” says Thomas Skoglund, associate professor of neurosurgery at the University of Gothenburg, neurosurgeon at the University Hospital, and one of the study’s co-authors.
Better understanding of intracerebral hemorrhages
The findings were significant regardless of the location within the cerebrum. Physically active individuals exhibited reduced bleeding in both the deep regions of the brain, which are often associated with high blood pressure, and the surface regions, which are linked to age-related conditions like dementia.
The study creates scope for further research on intracerebral haemorrhages and physical activity. Katharina Stibrant Sunnerhagen, professor of rehabilitation medicine at the University of Gothenburg and senior consultant physician at Sahlgrenska University Hospital, oversees the study.
“We hope that our findings contribute to a deeper understanding of intracerebral haemorrhages and aid in the development of more effective preventive measures” she concludes.
A University of Gothenburg study shows that after a stroke, physical activity can be pivotal to successful recovery. People who spend four hours a week exercising after their stroke achieve better functional recovery within six months than those who do not.
The study, published in JAMA Network Open, analysed data from 1500 stroke patients who were grouped according to their post-stroke patterns of physical activity.
The results show that increased or maintained physical activity, with four hours’ exercise weekly, doubled the patients’ chances of recovering well by six months after a stroke. Men and people with normal cognition kept up an active life relatively more often, with better recovery as a result.
Positive programming from exercise
The researchers have previously succeeded in demonstrating a clear inverse association between physical activity and the severity of stroke symptoms at the actual onset of the condition. These new findings highlight the importance of maintaining a healthy, active lifestyle after a stroke.
The first and corresponding author of the study, Dongni Buvarp, is a researcher in clinical neuroscience at Sahlgrenska Academy, University of Gothenburg. Besides her research internship, she is a resident doctor at an initial stage of specialist training at Sahlgrenska University Hospital.
“Physical activity reprograms both the brain and the body favourably after a stroke. Exercise improves the body’s recovery at the cellular level, boosts muscle strength and well-being, and reduces the risk of falls, depression, and cardiovascular disease. Regardless of how severe the stroke has been, those affected can derive benefits from exercising more,” she says.
Knowledge and support vital
“Being physically active is hugely important, especially after a stroke. That’s a message that health professionals, stroke victims and their loved ones should all know. Women and people with impaired cognition seem to become less active after stroke. The study results indicate that these groups need more support to get going with physical activity,” Buvarp says.
One weakness of the study is that, with a few exceptions, the researchers were unable to study the participants’ degree of activity before the stroke. The patients included were treated in Sweden in the period from 2014 to 2019.
With a three-day weekend being trialled in countries across the globe, new empirical research by Australian researchers shows that the extra time off increases active healthy behaviours, lending extra support to a shorter but still productive work week.
The researchers assessed study participants’ changes in daily movements before, during and after holidays, finding that physical activity increased when they were on holiday, even with just a three-day break. Their findings were published in the International Journal of Behavioral Nutrition and Physical Activity.
Across the 13-month study period, participants generally took two to three holidays on average, each being around 12 days. The most common holiday type was ‘outdoor recreation’ (35%), followed by ‘family/social events’ (31%), ‘rest and relaxation’ (17%) and ‘non-leisure pursuits’ such as caring for others or home renovations (17%).
Specifically, it showed that on holiday, participants:
engaged in 13% more moderate-to-vigorous physical activity (MVPA) each day (or five min/day more)
were 5% less sedentary each day (or 29 min/day less)
slept 4% more each day (or 21 min/day more).
University of South Australia researcher Dr Ty Ferguson says that the research indicates that people display healthier behaviours when they are on holiday.
“When people go on holiday, they’re changing their everyday responsibilities because they’re not locked down to their normal schedule,” Dr Ferguson says.
“In this study, we found that movement patterns changed for the better when on holiday, with increased physical activity and decreased sedentary behaviour observed across the board.
“We also found that people gained an extra 21 minutes of sleep each day they were on holiday, which can have a range of positive effects on our physical and mental health. For example, getting enough sleep can help improve our mood, cognitive function, and productivity. It can also help lower our risk of developing a range of health conditions, such as obesity, diabetes, cardiovascular disease, and depression.
“Interestingly, the size of these changes increased in line with the length of the holiday – so the longer the holiday, the better the health benefits.”
The study used data from the Annual rhythms in adults’ lifestyle and health (ARIA) study where 308 adults (mean age 40.4 years) wore fitness trackers 24 hours a day for 13 months. Minute-by-minute
movement behaviour data were aggregated into daily totals to compare movement behaviours pre-holiday, during holiday and post-holiday.
Senior researcher UniSA’s Prof Carol Maher says that the study offers support for the growing movement for a four-day week.
“A shorter working week is being trialled by companies all over the world. Not surprisingly, employees reported less stress, burnout, fatigue, as well as better mental health and improved work-life balance,” Prof Maher says.
“This study provides empirical evidence that people have healthier lifestyle patterns when they have a short break, such as a three-day weekend. This increase in physical activity and sleep is expected to have positive effects on both mental and physical health, contributing to the benefits observed with a four-day work week.
“Importantly, our study also showed that even after a short holiday, people’s increased sleep remained elevated for two weeks, showing that the health benefits of a three-day break can have lasting effects beyond the holiday itself.
“As the world adapts to a new normal, perhaps it’s time to embrace the long weekend as a way to boost our physical and mental health.”
