By Karina Ninni

THE STAR/ FAPESP – A study published in the journal Blood Pressure Monitoring shows that the benefits of physical activity for hypertensives (people with high blood pressure) can be boosted if it takes place between 6pm and 9pm.

The analysis focussed on heart rate recovery (HRR), commonly defined as the deceleration in heart rate after cessation of exercise.

Exercising in the evening improved both the fast phase of HRR, measured 60 seconds after physical effort peaked, and the slow phase, measured 300 seconds after the peak.

The investigation was conducted by postdoctoral fellow Leandro Campos de Brito, under the supervision of a professor at the University of São Paulo’s School of Physical Education and Sports (EEFE-USP) in Brazil Cláudia Lúcia de Moraes Forjaz.

The experiment involved 49 middle-aged hypertensive men who had been medicated for at least four months with the same type of drug and the same dosage regimen.

They were divided randomly into three groups: morning exercise (7-9am), evening exercise (6-9pm) and control (no aerobic training).

The participants carried out the training programme three times a week for 10 weeks, exercising with moderate intensity on a stationary bicycle for 30 minutes in the first two weeks and for 45 minutes thereafter.

The control group did stretching exercises that would have no effect on the HRR for 30 minutes.

In assessments conducted before and after the programme, HRR was measured 60 seconds and 300 seconds after cessation of exercise.

Evening effect
According to Dr Brito, about one in four of the participants did not respond to the training programme in terms of blood pressure control, and non-conventional strategies are required for these patients, such as training at a time of day when benefits are maximised.

His initial idea during his PhD research was to study the long-term effects of exercise in terms of cardiovascular (heart) benefits in general.

This included HRR as a measure of cardiac autonomic regulation.

“Cardiac autonomic regulation has sympathetic and parasympathetic components.

“The latter makes the heart rate slow down, while the former makes the heart accelerate and beat more strongly,” he explained.

“After a period of exercise training, the power of the parasympathetic system is expected to increase (relaxing the heart) and that of the sympathetic system should decrease.

“This mechanism can be inferred by measuring HRR in the first 60 seconds (a typically parasympathetic response) and 300 seconds after the end of a maximum cardiopulmonary effort test.

“The latter response points to both the efficacy of the parasympathetic nerves in HRR and deceleration of the sympathetic component, which intensifies during exercise.”

According to the researchers, the fact that both the fast and slow phases of HRR increased during evening exercise suggests that training in the evening is beneficial for both parasympathetic and sympathetic components of the cardiac autonomic system.

The results also show that the beneficial effects of evening exercise are not limited to the length of the exercise itself.

“We evaluated people in the morning and evening, and the results of both assessments were better for those who trained in the evening,” Dr Brito said.

Possible reason
The researchers are working to understand the mechanisms that make the improvement from evening exercise more significant.

During Dr Brito’s PhD research, he and his colleagues discovered that baroreflex sensitivity (an autonomic mechanism that controls arterial blood pressure between heartbeats) increased as a result of exercise training.

“Each time your heart beats, the baroreflex mechanism assesses whether blood pressure has risen or fallen too much, and corrects it.

“Better baroreflex sensitivity means better health,” he explained.

“Both morning and evening exercise improved it, but evening exercise improved it more.

“However, this was a spontaneous measurement made while the subject was at rest.

“As part of my postdoctoral research, we’re stimulating baroreflex sensitivity to the utmost with medications.”

He added, “No one is at rest all the time. We all have to deal with physical, cognitive and emotional challenges, and this autonomic control is required for those as well.”

Cardiovascular functions vary during the 24 hours of any day.

“What’s expected is that when we wake up in the morning, our blood pressure rises, peaking around 10am, and stabilises until mid-afternoon, around 3pm, when it falls a little,” Dr Brito explained.

“It peaks again between 6pm and 8pm, after which it declines.

“Both blood pressure and heart rate are lowest in the small hours before dawn.

“Our proposition is that evening exercise occurs in a window of opportunity for a significant improvement.”

Baroreflex sensitivity is better and the sympathetic system less active in the evening.

“In addition, the 24-hour cycle entails a lower heart rate and less resistance in blood vessels in the evening, a time when stress on the cardiovascular system is low.

“This appears to explain why evening exercise is more beneficial.

“It’s a hypothesis to explain our results,” he said.

Morning exercise is also beneficial, but less so. “It’s important to say that any time of day is better than none as far as exercise is concerned. In other words, we need exercise.

“Our study aimed at maximising responses,” Dr Brito said.

Resistant hypertensives, who take anti-hypertensive medication four or more times per day, need a better approach to the problem than the conventional ones.

“Our results are very relevant to the treatment of these patients,” he said. At least 150 minutes of moderate exercise per week is the recommendation for an adult.“If you do only the 150 minutes, you’re seven per cent less likely to become hypertensive in adulthood.

“The exercise can be any kind of activity, including housecleaning.

“For those who are already hypertensive, doing the recommended minimum reduces the likelihood of complications from high blood pressure by 50 per cent,” he said.

Physical activity in general significantly improves the control of blood pressure.
“Structured aerobic exercise is as beneficial for hypertensives as taking anti-hypertensive medication.

“In the guidelines issued by the Brazilian Hypertension Society (SBH), the first recommendation is a change of lifestyle, not the use of medication, if permitted by the patient’s clinical condition,” said Dr Brito, who also heads SBH’s physical education department.

“All hypertensives should get regular aerobic exercise.”

CNA – Has your home recently been overrun by tiny grey moths, flapping erratically around your kitchen? Spotted some suspicious webs in a cereal box? You might be sharing your dried food with pantry moths (also known as plodia interpunctella).

Although several species of moth can live and breed in our homes, the pantry moth (also known as the ‘Indian meal moth’) is one of the most common unwanted moth-guests.

Pantry moths are found on every continent except Antarctica. They feed on rice, grains, flour, pasta, cereals, dried fruits, spices, seeds, nuts and other dried food. Their fondness for dried foods makes them a major pest in food storage facilities. So how did they get in your house – and what can you do to get rid of them?

LARGE AMOUNTS OF SILK WEBBING AND FAECES

Like other moths, pantry moths have four distinct life stages: Egg, caterpillar, pupae and adult. The first sign of a pantry moth infestation is often the sight of adult moths flying in an erratic, zig-zag path around our kitchens.

Pantry moth adults have grey wings with bronze or tan bands near the wing tips.

Although they can be annoying, adult moths do not feed at all. The trouble arises when female moths lay their eggs in or around our food.

The tiny eggs hatch into barely visible cream-coloured caterpillars small enough to crawl into poorly sealed food containers. There, they begin to feed.

As they grow, caterpillars produce large amounts of silk webbing and faeces, both of which can contaminate food.

Once a caterpillar reaches its full size, it leaves the food in search of a safe space to make a cocoon, usually a crack, container lid, crevice or corner. Sometimes they turn up in the hinges of a pantry door. A few weeks later, an adult moth emerges from the cocoon, ready to start the cycle again.

HOW DID PANTRY MOTHS GET IN MY HOUSE? AND WHY ARE THEY MORE COMMON LATELY?

Unfortunately, it’s likely you brought them home yourself. Although pantry moths can enter via doors and windows, most infestations probably start when we inadvertently bring home eggs and caterpillars in our dried foods.

Kitchens full of unsealed containers and spilled food create an irresistible smorgasbord for female moths looking for the ideal place to lay eggs. Like many insects, pantry moths develop more quickly at warmer temperatures.

At warmer temperatures, females also lay more eggs and caterpillars are more likely to survive to adulthood.

But prolonged exposure to temperatures above 40 degrees Celsius are lethal to eggs and caterpillars.

While pantry moths can be found at any time of the year, the warm temperatures of late spring and early summer are often perfect for supporting rapid population growth.

HOW DO I GET RID OF PANTRY MOTHS?

First, eliminate their sources of food. Dry goods should be stored in sealed, airtight containers with tight-fitting lids.

To prevent eggs and caterpillars from hitchhiking in on purchases, place dried foods in the freezer for three to four days; this should kill any eggs and caterpillars that may be present.

If you already have an infestation, carefully inspect all potential food sources including spices, cereals, grains, dry pet foods, pasta, seeds, nuts, tea, dried flowers and dried fruit.

Pantry moth caterpillars are hard to see; look for the silken webbing they produce, which can cause food grains to clump together. These webbed clumps are often more conspicuous than the caterpillars themselves.

Infested foods should either be discarded or placed in the freezer for three to four days to kill eggs and caterpillars.

Clean up and discard any spilled foods on shelves, under toasters or behind storage containers. Even small amounts of food can support thriving caterpillar populations.

Caterpillars can travel considerable distances to find a safe place to make a cocoon, so make sure to check shelves, walls, crevices and ceilings. Moth cocoons can be removed by wiping with a damp cloth or with a vacuum cleaner.

Cleaning and proper food storage are the best ways to end a pantry moth outbreak.

Sticky pantry moth traps are commercially available and can be used to monitor and reduce the moth population.

Pantry moth traps – triangular cardboard covered with a thick sticky glue – are baited with a chemical that mimics the smell of a female pantry moth.

Males are attracted to the trap and become hopelessly stuck to the glue. Since sticky traps only target males, traps are unlikely to stop an outbreak on their own; always use them with proper food storage and careful cleaning.

Insecticide sprays are unlikely to be effective as pantry moth caterpillars and eggs are protected within food containers.

Pantry moths are also resistant to a range of insecticides, rendering them ineffective. Insecticides should never be applied on or near food.

WHAT IF I ATE SOME PANTRY MOTH EGGS OR LARVAE?

While it can be disconcerting to find tiny caterpillars in the cereal you’ve been enjoying all week, accidentally eating pantry moth caterpillars is unlikely to cause any health problems.

Given how common they are in stored food, you’ve probably already unknowingly consumed many moth eggs and larvae.

Thank goodness caterpillars are generally an excellent source of protein.