Forced Exercise Less Beneficial than Voluntary

The Effects of Voluntary, Involuntary, and Forced Exercises on Brain-Derived Neurotrophic Factor and Motor Function Recovery: A Rat Brain Ischemia Model – free full-text /PMC3035657/ – Feb 2011

I was happy to find that what I have personally experienced has been proven to be true: forced exercise is not as beneficial as voluntary. Sometimes science actually proves our intuitions correct – surprise!

Stroke rehabilitation with different exercise paradigms has been investigated, but which one is more effective in facilitating motor recovery and up-regulating brain neurotrophic factor (BDNF) after brain ischemia would be interesting to clinicians and patients.

  • Voluntary exercise,
  • forced exercise, and
  • involuntary muscle movement caused by functional electrical stimulation (FES)

have been individually demonstrated effective as stroke rehabilitation intervention.

Methodology/Principal Findings

One hundred and seventeen Sprague-Dawley rats were randomly distributed into four groups:

  • Control (Con),
  • Voluntary exercise of wheel running (V-Ex),
  • Forced exercise of treadmill running (F-Ex), and
  • Involuntary exercise of FES (I-Ex) with implanted electrodes placed in two hind limb muscles on the affected side to mimic gait-like walking pattern during stimulation.

Ischemic stroke was induced in all rats. Twenty-four hours after reperfusion, rats were arranged to their intervention programs.

De Ryck’s behavioral test was conducted daily during the 7-day intervention as an evaluation tool of motor recovery. Serum corticosterone concentration and BDNF levels in the hippocampus, striatum, and cortex were measured after the rats were sacrificed.

V-Ex had significantly better motor recovery in the behavioral test. V-Ex also had significantly higher hippocampal BDNF concentration than F-Ex and Con.

F-Ex had significantly higher serum corticosterone level than other groups.

Corticosterone is a stress hormone, so this means the forced exercise causes stress.

Conclusion/Significance

Voluntary exercise is the most effective intervention in upregulating the hippocampal BDNF level, and facilitating motor recovery.

Rats that exercised voluntarily also showed less corticosterone stress response than other groups.

The results also suggested that the forced exercise group was the least preferred intervention with

  • high stress,
  • low brain BDNF levels and
  • less motor recovery.

Voluntary and involuntary running in the rat show different patterns of theta rhythm, physical activity, and heart rate | Journal of Neurophysiology – free full-text – May 2014

Involuntarily exercising rats undergo more physical and mental stress than voluntarily exercising rats; however, these findings still lack electrophysiological evidence.

Many studies have reported that theta rhythm appears when there is mental stress and that it is affected by emotional status.

Thus we hypothesized that the differences between voluntary and involuntary movement should also exist in the hippocampal theta rhythm

Using the wheel and treadmill exercise models as voluntary and involuntary exercise models, respectively, this study wirelessly recorded the hippocampal electroencephalogram, electrocardiogram, and three-dimensional accelerations of young male rats.

Treadmill and wheel exercise produced different theta patterns in the rats before and during running.

When the same movement-related parameters are considered, the treadmill running group showed more changes in their theta frequency (4–12 Hz), in their theta power between 9.5–12 Hz, and in their heart rate than the wheel running group.

A positive correlation between the changes in high-frequency (9.5–12 Hz) theta power and heart rate was identified.

Our results reveal various voluntary and involuntary changes in hippocampal theta rhythm as well as divergences in heart rate and high-frequency theta activity that may represent the effects of an additional emotional state or the sensory interaction during involuntary running by rats.

Furthermore, theta activity also represents various special cognitive functions and/or special learning-related functions; therefore, an increase in theta power may be related to higher cognitive functioning and special learning functions

Treadmill running and wheel running are the most commonly used exercise models when studying rodents.

Treadmill exercise with defined exercise parameters (intensity, duration, etc.) can be considered an involuntary exercise model.

Wheel exercise, in which the rats can run freely in their cages, can be considered a voluntary model.

Compared with treadmill running (involuntary exercise model), wheel running (voluntary exercise model) causes lower levels of stress. Involuntary exercise results in a higher concentration of serum corticosterone but also results in reduced spatial learning and aversive memory after long-term training compared with voluntary exercise.

Since treadmill exercise causes a wide range of neuronal responses that may be related to stress, previous studies have identified that these two exercise models result in different types of brain functioning

In this study, we compared voluntary and involuntary exercise, using the wheel and treadmill models.

We have established a free-moving rat model that can be used to study various cerebral mechanisms simultaneously during treadmill exercise and wheel running, even in a pipe

The rats can run freely without physical restraint; in this context, any limits to their movement could result in a discontinuity of motion

We hypothesize that voluntary and involuntary exercise cause different patterns of theta rhythm before and during running. The different sensory stimuli from different types of exercise may affect theta rhythm.

The aims of the present study are as follows:

  1. first, to determine whether voluntary and involuntary exercise cause different changes in theta rhythm, both before and during running;
  2. second, to compare the two running models when the rats have the same movement-related parameters (physical activity, speed, heart rate); and
  3. third, to explore the relationship during running between theta rhythm and heart rate and between theta rhythm and physical activity.

Our study has established a platform for comparing the effects of voluntary and involuntary running on theta rhythm, heart rate, and physical activity. We used the wheel and treadmill running models as systems that allow voluntary and involuntary movement, respectively.

When the chronological order of running was examined, both wheel and treadmill running group showed increases in theta rhythm, heart rate, and physical activity

the treadmill running group was found to undergo more changes in Frq and HT of the theta rhythm and heart rate compared with the wheel running group when they had the same running speed and when they had the same heart rate.

This study is the first study to compare the differences in hippocampal theta rhythm between voluntary and involuntary movement

It is well known that both mental and physiological stresses are able to change heart rate.

Compared with an animal undertaking voluntary movement, involuntary running animals suffer more stress, especially psychological stress.

During forced exercise the rat is unable to be in control of speed and duration of movement.

the wheel running group showed fewer changes in heart rate across all situations than the treadmill running group. These results suggest that there exist factors other than physiological stress that are causing the increment in heart rate.

…that’s because heart rate responds to stress of involntary activity, while only the activity itself increases heart rate in voluntary exercise.

Compared with treadmill running rats, the wheel running rats ran in the same place, but the view was more extensive. Thus the sensory information is more complicated during wheel running than during treadmill running.

Conclusions

Voluntary and involuntary running show distinct theta patterns before and during running.

Involuntary running causes increases in theta frequency, high-frequency theta activity, and heart rate compared with voluntary running.

These discrepancies in high-frequency theta activity and heart rate between two exercise groups may represent the emotional status or the sensory interaction that occurs during running by the rat.

When exercise is forced by necessity or fear, like the fear of worsening pain if I don’t exercise, it becomes a painful, difficult, miserable chore. I get no pleasure from it or even after it (except that it is finally over) and the immediate pain from the activity feels overwhelming.

Only when I exercise because I’m feeling pretty good already, like when the worst of my pain is under control by opioids, do I feel any pleasure from it. Even when my joints pinch and muscles burn a bit, I feel like I’m really accomplishing something.

And here’s another study pointing out the same issue:

Effects of voluntary and involuntary exercise on cognitive functions, and VEGF and BDNF levels in adolescent rats. – PubMed – NCBI – Jan 2015

We investigated the effects of voluntary and involuntary exercise on the

  • prefrontal cortex and hippocampus,
  • vascular endothelial growth factor (VEGF),
  • brain-derived neurotrophic factor (BDNF) levels, and
  • spatial learning,
  • memory and
  • anxiety

in adolescent male and female rats.

The voluntary exercise group was given free access to a running wheel for 6 weeks. The involuntary exercise group was forced to run on a treadmill for 30 min at 8 m/min 5 days/week for 6 weeks.

Improved learning was demonstrated in both exercise groups compared to controls.

Neuron density in the CA1 region of the hippocampus, dentate gyrus and prefrontal cortex were increased. Hippocampal VEGF and BDNF levels were increased in both exercise groups compared to controls.

In females, anxiety and corticosterone levels were decreased;

This surprises me because when I’m stuck in it, my anxiety never eases no matter how much I exercise.

BDNF and VEGF levels were higher in the voluntary exercise group than in the involuntary exercise group.

The adolescent hippocampus is affected favorably by regular exercise.

And here’s a real surprise: males and females are affected differently by forced exercise.

  • Although no difference was found in anxiety levels as a result of involuntary exercise in males,
  • females showed increased anxiety levels, and decreased VEGF and BDNF levels in the prefrontal cortex after involuntary exercise.

Decreased BDNF means that the exercise was not as beneficial.

There are more and more reasons not to assume that research ignoring gender differences applies to both. All the studies on medications ignore the gender of the subjects and just lump them all together.

And the gender differences are just one of the significant differences between individuals that aren’t accounted for in research: there are different body types and personalities that have different reactions to different treatments.

The effects of opioids on different individuals depend on what’s going on with that person. If they have a predisposition to developing an addiction, they may get in trouble, but other people who have no such tendencies can use opioids responsibly and safely.

Why are responsible users of opioids punished for the acts of other people?

What does a patient with a desperate need for relief from overpowering pain have in common with someone injecting street drugs?

There is very, very little overlap between these two distinct groups.

5 thoughts on “Forced Exercise Less Beneficial than Voluntary

  1. leejcaroll

    Sometimes one has to do “involuntary” whether they want to or not. I refused to do it many years ago after surgery in my chest. I have suffered with shoulder discomfort ever since. Stroke vicitms others who lose ability to move various parts of their bodies need to be “forced” to exercise if they want to regain motility, use of arms hands, etc back which leads to a better sense of control. If my back is acting up and I choose not to exercise then I have onlymyself to blame when the pain gets much worse (I do this too often andalways pay for it later)
    As to opioids I understand your point but I find it distressing that almost any article about chronic pain that I read whether here,pain news network, online responses to an article no matter the subject regardlessof how far afield from opioids ends up being about opioids

    Liked by 1 person

    Reply
    1. Zyp Czyk Post author

      I certainly know what it’s like to do “forced” exercise because activity that used to be such a joy for me (hiking, biking) often leaves my joints in agony and muscles with searing pain after only a short distance. Yet, I’m forced to continue to either make it back home or back to the car. It would be absolutely intolerable if I hadn’t been a workout-junkie for much of my life and wasn’t used to lots of muscle and joint pain. Yes, I know this is probably overdoing it, but I’ve always had the need to fling myself against my physical limitations, and these days, that’s all that stands between me and total deconditioning.

      Of course, there’s still a huge difference between such “coerced” exercise and running for your life, like I’m sure the rats felt. The few times I had to use bursts of energetic strength in an emergency situation (like rescuing a horse from a tipped over trailer), it felt like I’d torn my body to pieces and it took me days to recover.

      Liked by 1 person

      Reply
  2. leejcaroll

    you have to wonder too if to the rats on the wheel didnt also feel tremendous pressure as the circumstances of their stroke and activity are not at the end of the day “voluntary”.

    Liked by 1 person

    Reply
  3. Kathy C

    They are still promoting “exercise” for people with chronic pain, even if it is stressful or causes distress and even tissue damage. In many cultures they get physical activity by engaging in every day pleasant activities, like walking to work or a store, gardening or hobbies. Many people especially low income America do not have access to these kinds of activities. Walking is unpleasant and dangerous through bad neighborhoods, urban blight, 8 lanes of speeding traffic. There is also the added benefit of social interactions. These kinds of activities are not safe for many Americans, and “exercise” is monetized, as something one does in a smelly crowded gym.

    Of course if one has chronic pain and gets injured during exercise, they will have to suffer it out by themselves. The healthcare industry has not only ignored these problems, but continues to gaslight people about exercise. We never hear about the injuries, deaths, and mistakes like the under insured people who can’t work for weeks after an injury. They continue to shame people who work blue collar jobs doing strenuous physical activity, because they don’t get enough exercise. In America even something that is beneficial has been weaponized, and used to deny access to healthcare, or to belittle and demean sick people. We live in the land of alternate facts.

    Liked by 1 person

    Reply
    1. Zyp Czyk Post author

      Suggesting that everybody should indiscriminately exercise is just another “standard” being forced upon us. I have permanent damage from doing yoga to “fix” my back pain.

      To be effective, medical care must be tailored to the individual.

      Liked by 1 person

      Reply

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