“We find that people who are in better shape fill fewer prescriptions for anxiety and depression medications,” says Linda Ernstsen, the senior author of the article and an associate professor from the Department of Public Health and Nursing at the Norwegian University of Science and Technology (NTNU).

The research group based its work on the  Trøndelag Health Study (HUNT). Since 1984, 250,000 Trøndelag residents have voluntarily contributed their health data to this comprehensive research project. The data are available to researchers, who can use the data to estimate people’s fitness levels, among other things.

The figures were taken from the third data collection round, called HUNT3, which was conducted from 2006 to 2008.

The research group compared the data from HUNT3 with data from the Norwegian Prescribed Drug Registry, which provides an overview of medications that have been dispensed in Norway.

Reduces the need for medication

“Being in better physical shape appears to reduce the need for anxiolytic drugs and antidepressants,” Ernstsen said.

In a previous study, Ernstsen and her co-authors found that people who were in good physical shape during the second HUNT study had a lower prevalence of depressive symptoms when they were participants in HUNT3 ten years later. However, at the time, the researchers found no correlation between good physical shape and anxiety.

But the new study design, which allows the researchers to look at what kinds of medication HUNT3 participants obtained from pharmacies as late as 2018, allowed the researchers to find the correlation.

However, the study does have a theoretical catch. The researchers can only see what kinds of medication were dispensed to people by pharmacies. They cannot see whether people actually took the medication — there’s no way to monitor people at their medicine cabinets.

“Nevertheless, there is reason to believe that people who are prescribed medication have more symptoms than those who do not see a doctor,” according to first author Audun Havnen, an associate professor at the Department of Psychology at NTNU.

Greatest effect for men and young people

Being in good physical shape helps all age groups and both genders. However, some people get greater benefits from exercise and being in good physical shape than others.

“We find that men experience a greater effect from exercise than women. The correlations are also less clear for the elderly,” Ernstsen says.

But that doesn’t mean that it isn’t important for women and the elderly to exercise.

What came first?

We can, of course, ask what triggers what. Is it actually the case that good physical health helps prevent anxiety and depression? Or is it the case that people who suffer from anxiety and depression exercise less and are therefore in poorer shape?

In order to not include anyone who was already experiencing anxiety or depression at the start of the study, the researchers excluded anyone who had filled prescriptions for these conditions before participating in HUNT3, as well as for three months afterwards.

“We also adjusted for symptoms of anxiety and depression in statistical analyses. To the extent that the figures can be believed, we also feel fairly confident that we started with a relatively anxiety and depression-free cohort in HUNT3,” Ernstsen said.

In other words, the subjects were unlikely to have suffered from anxiety or depression beforehand.

Unfortunately there are no shortcuts for people who can’t be bothered to exercise. We simply have to get started — unless we decide to give up. But is there really no other alternative?

“The results indicate that you can achieve a protective effect by improving your physical shape from poor to moderate, so any activity is beneficial,”  Havnen says.

You should be physically active in a way that leaves you breathless and sweaty if you want to improve or maintain your physical condition. The Norwegian health authorities recommend that adults be physically active for at least 150 to 300 minutes at moderate intensity each week.

However, one option for people who are short on time is to aim for 75 minutes of high-intensity training each week or a combination of moderate and high-intensity training.

“Research reinforces the finding that each minute of physical activity counts,” Ernstsen said.

Authored by Audun Havnen, Ekaterina Zotcheva, Ottar Bjerkeset, Xuemei Sui, and Linda Ernstsen, “Cardiorespiratory fitness and incident use of anxiolytics and antidepressants in adults. A linkage study between HUNT and the Norwegian Prescription Database” appeared in the Journal of Affective Disorders.

Want the health benefits of exercising, but aren’t too keen on pounding the pavement or pumping iron every day?

Edith Cowan University (ECU) may be able to clarify how many times per week you need to exercise to make it worth your while.

A new study saw participants perform a single three-second, maximum-effort eccentric bicep contraction — similar to slowly lowering a heavy dumbbell, from a bent arm to a straight arm.

Previous ECU research showed this can significantly improve muscle strength when it’s performed daily for five days a week (Monday – Friday), for four weeks.

Participants in the new study were split into two groups, with the first group performing a single three-second contraction two days per week, and the other performing the same exercise on three days per week.

After four weeks, researchers compared the participants’ bicep strength.

Those who performed the exercise two-days per week saw no significant changes, however the three-day group saw small but significant increases in concentric strength (2.5 per cent) and eccentric strength (3.9 per cent).

Study lead Professor Ken Nosaka said the results helped to further improve our understanding of how our body responds to exercise — and how people can then put that knowledge to good use.

“Our previous work has shown regular, shorter exercise is more beneficial than a one or two big training sessions in a week,” Professor Nosaka said. “Now, we have a clearer idea of where the tipping point is where you start to see meaningful benefits from such a minimal exercise. These new results suggest at least three days a week are required, at least for the single three-second eccentric contraction training.”

Three is good… but five is better

While the findings showed three days per week will have an impact, finding the willpower to put in a couple of extra days of exercise per week will produce better results.

The previous study’s participants who performed the exercise five days a week saw greater improvements in strength — more than 10% increases — than the three-day group.

However, Professor Nosaka stressed this didn’t mean exercising every day would improve results even further.

“Muscle adaptations occur when we are resting, so muscles need rest to improve their strength and their muscle mass,” he said. “It should be noted that the exercise was only three seconds, so the rest between exercises in the study was close to 28,800 times more than the exercise time. But muscles do appear to like to be stimulated more frequently, especially for the small volume of muscle strengthening exercise.”

Applying it to real life

Professor Nosaka said more research was needed to see if the study’s findings apply to other types and volumes of exercise.

“Muscles enjoying frequent stimulation may not necessarily be the case for a greater volume of aerobic exercise to improve cardiovascular function, or muscle strengthening exercise such as working out at a gym,” he said.

“However, it may be that exercising once a week for 2 hours is less effective than exercising every day for 20 minutes.

“If it is not possible to have 20 minutes a day for exercise, even five minutes a day makes a difference for fitness and health.

“Of course, more studies are needed to confirm this, but our recent studies show the importance of accumulating small amount of exercise as frequently as possible in a week.

“It is important to note that even a very small amount of exercise can make a difference to our body, if it is performed regularly.”

‘Weekly minimum frequency of one maximal eccentric contraction to increase muscle strength of the elbow flexors’ was published in the European Journal of Applied Physiology.

Applying ice to a muscle injury is a widespread first-aid treatment, but exactly what effect does this have on the muscle regeneration and does it really help? Cumulative research by a multi-institutional Japanese research collaboration reveals that ‘to ice or not to ice’ may depend on the degree of muscle injury.

In their latest research, the group consisting of Associate Professor ARAKAWA Takamitsu and Master’s student NAGATA Itsuki (from Kobe University’s Graduate School of Health Sciences), and Assistant Professor KAWASHIMA Masato (Kawasaki University of Medical Welfare) et al. have shown that applying ice to muscle damage in a small percentage of muscle fibers in rats promotes muscle regeneration. This is believed to be the first study in the world to show benefits of icing on muscle repair. In conjunction with their previous study on serious muscle injuries (‘Icing muscle injuries may delay recovery’), it is hoped that these results can be used as a basis for more accurate guidelines on whether or not to ice such injuries.

These research findings were first reported in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology on March 6, 2023.

Main Points

• The experiments showed that applying ice after a mild muscle injury promotes muscle regeneration.
• This is believed to be the first time in the world that a study has shown a positive effect of icing on muscle regeneration.
• The researchers showed that the extent of the injury may have a greater impact on the effectiveness of icing than the method or timing employed.
• The findings of this ongoing research will lead to the spread of more accurate information on the effects of icing throughout hospitals, and in the realms of sports and physical education.

‘RICE treatment’ is a common approach for treating the acute phase of sports injuries. This acronym stands for Rest, Ice, Compression and Elevation and it is also often used in physical education in schools and even clinical settings. There are a variety of subsequent steps that can be taken to treat the injury afterwards, yet opinions vary as to whether or not icing should be applied. However, there is a lack of evidence on the benefits of icing.

The current research team has conducted many experiments to investigate the effectiveness of icing, which led them to publish their previous findings (‘Icing muscle injuries may delay recovery’ ). However, no previous animal experiments have indicated that icing promotes muscle regeneration.

In this study, the researchers focused on altering the severity of the muscle injury in the experiments. The reasoning behind this was that the majority of sports-related muscle injuries are limited; in other words less than 10% of the overall number of muscle fibers (myofibers) are damaged and necrotized. However, all animal experiments up until now had looked at more serious injuries where over 20% of the myofibers were damaged.

Thus, the team devised an animal model for mild muscle injuries, and experimented with applying ice after injury using a similar method as before.

After the animal was anaesthetized, the muscle was exposed and clamped between forceps to induce injury. In their previous experiments, the researchers attached a 500g weight to the forceps, which induced an injury that affected 20% of the total number of fibers in the muscle. In the present study, they tried attaching a 250g weight to the forceps and demonstrated that this could be used to consistently injure 4% of the fibers (Figure 1). This is similar to the degree of injury that often occurs after sports activities such as vigorous exercise or long-distance marathon running.

Icing was carried out by placing polyethylene bags of ice on surface of the skin over three 30-minute sessions per day, with each session being 1.5 hours apart. This was continued until two days after injury for a total of 9 icing sessions (i.e. immediately after injury = 3 sessions, 1 day after injury = 3 sessions, 2 days after injury = 3 sessions). The icing method was the same as in the previously reported study (‘Icing muscle injuries may delay recovery’).

Observations of muscles that were regenerating in the icing group and no-icing group 2 weeks after injury revealed significant differences in the size of regenerating fibers in cross-sections (Figure 2). In other words, this demonstrated the possibility that skeletal muscle regeneration is promoted by icing.

Macrophages are immune cells that orchestrate the reparative process of injured muscle. Pro-inflammatory macrophages accumulate in the damaged site soon after injury occurs, however they express an inducible nitric oxide synthase (iNOS), which has a disadvantageous side-effect of expanding the injury’s size. The results of this team’s experiments revealed that icing after mild muscle injury reduces the accumulation of iNOS-expressing pro-inflammatory macrophages. By causing this phenomenon, icing prevents the expansion of muscle injury size.

In other words, icing attenuates the recruitment of pro-inflammatory macrophages in the injury site. This was also reported in their previous study (‘Icing muscle injuries may delay recovery’), demonstrating that this is an effect caused by icing regardless of whether the muscle injury is serious or mild. In the previous study, icing was found to delay the regeneration of muscle after a serious injury that destroyed many fibers because the pro-inflammatory macrophages were unable to sufficiently phagocytose (*5) the injured muscle. In contrast to this, the current study shows that icing has a positive effect when the muscle injury is mild because it prevents the secondary expansion of the muscle injury caused by the pro-inflammatory macrophages. It suggests that this particular effect of icing is connected to the promotion of muscle regeneration.

Icing has been used in the treatment of muscle injuries for a long time, however the positive effects of icing had yet to be elucidated until now. This study has shown that icing can promote muscle regeneration when used to treat commonly-occurring mild muscle injuries.

However, this does not mean that icing is effective for all types or degree of muscle injury. The researchers aim to further elucidate and raise awareness of this. For example, the group’s previous study showed that icing actually inhibited regeneration in cases of serious muscle injury. In addition, the term ‘muscle injury’ also includes extremely minute injuries that have yet to be observed through the team’s animal experiments, so it is still unclear as to what effect icing has on the repair from such microtraumas.

The researchers’ next challenge is to determine the extent of muscle injury up to which icing is appropriate. By building upon their previous investigations, they aim to contribute towards guidelines that will enable people in sports and clinical rehabilitation to make accurate judgements about whether or not to ice an injury.