Exercise- The New Drug?

Anti-inflammatory and Pain killer effects of exercise

We all know that exercise has numerous health benefits.

However recent WHO review is alarming.   

1 in 4 adults is not physically active as per the recommended guidelines.

 It is a wake-up call.

Sedentary lifestyle, work-life imbalance, personal and financial commitments are common reasons for physical inactivity.

Persistent low-grade inflammation is the latest known potential contributing factor for lots of chronic diseases like diabetes, heart attack, stroke, neurodegenerative diseases like dementia, Parkinson’s, Alzheimer’s.

Currently, these diseases are a big burden to our society and at present these are traditionally managed by our medical system- doctor follow-ups to tune the dosage of medications, diagnostic investigations, and so on. Yet these are reactive responses which I feel is a late action.

We have new evidence to point us that exercise and physical activity can eliminate low-grade inflammation and lower our sensitivity to pain.

This article will mainly explore the benefits of exercise on a) low-grade inflammation b) exercise-induced hypoalgesia- both may be new terminologies for some, but stay with me, I have made it simpler.  

Firstly... What is inflammation and its implications?

It is a repair process of our immune system. This defense program protects us from any pathogens or tissue injuries we sustain. Inflammation can be short-term or long-term; confined to one site of our body or widespread. For example, when there is a tissue injury, certain immune cells (eg: macrophages, Mast cells) detect a malfunction in the tissue, as consequence unique signals like ‘signature chemicals’ specific for that incident are produced.

During this process, the local tissue environment can be hostile towards pathogens and unfriendly chemicals that are ingested or, to a foreign object (eg wood splinter stuck in finger). For instance, fever is a sign of inflammation that our body is fighting against virus or bacteria; when we get a splinter in our finger or when we sprain our knee or ankle we may experience pain, warmth/ heat, swelling, redness, and loss of function. This is a sign that our body is actively repairing and harmony in the specific tissue is restored.

This harmony/ homeostasis of body tissue is maintained by the endocrine system (hormones) and signature chemicals from the nervous system with various other parameters like blood pressure, blood glucose levels, body temperature, etc.,

Persistent low-grade inflammation…

As much as inflammation has this protective security system in our body, severe inflammation or long-term low-grade persistent inflammation is not useful, and it is associated with multiple chronic diseases (certain blood tests will detect biomarkers like CRP that indicates inflammation)

Our Immune system can produce chemical information (ie. cytokines- cell to cell signaling molecules) that are pro-inflammatory (inducing) as well as anti-inflammatory (relieving) factors.

The presence of pro-inflammatory cytokines in our system is associated with cardiovascular disease, obesity, diabetes, and other neurodegenerative diseases.

Pro-inflammation…

Pro-inflammation is also capable of decreasing our pain threshold, so we gradually become too sensitive to something that is not expected to cause pain. For example, I see people who would report severe pain from walking 50 meters or standing for few mins. This isn’t an exaggeration, or because they are too weak. In persistent pain conditions (for eg: chronic low back pain, fibromyalgia, inflammatory bowel disease), complex changes take place in their body; nervous system, immune system and, the endocrine system gets dysregulated and, creates a vicious cycle in pain processing.

Their simple daily functions would pose a huge challenge. It impacts their mood, sleep quality, results in the inability to focus.  It is simply not due to achy joints, weak muscles, or arthritis, and this is called ‘pathological pain’.  Medications, multiple surgeries, endless massage, or manual therapy sessions (including physio) are often not an effective solution for this type of presentation.

Promising effects of exercise on inflammation…

Studies show that a single session of cardio exercise can release anti-inflammatory cytokines (pain killers) that can counteract these unfriendly pro-inflammatory cytokines. This was studied on young healthy population and still unclear about the exact mechanism, however, the result is encouraging that exercise is comparatively a less risky way of accessing analgesic benefits, at least for some people.

Because people in chronic pain may not find it as easy to exercise as a healthy adult. For some groups of people, a single exercise session may produce increasing pain, not due to damage from the exercise session, but because ‘pain processing system’. Gradual and guided increase in the intensity of physical activity is still recommended for people in chronic pain. Mindfulness training, yoga, Tai Chi, breathing exercises, and psychologically informed practice like Cognitive Behavioural Therapy and Acceptance and Commitment therapy could be other potential alternatives.

Exercise-induced hypoalgesia (hypo- reduction, algia- pain). – i.e exercise/ physical activity causing pain relief. [EIH]

 How?

As a physiotherapist, I prescribe exercise and promote physical activity to people who come to see me.

The most common question I get asked is ‘how does exercise improve pain?’.

Pertinent question and, occasionally I ponder the same. Some of the reasons I tell people are on basis of, ‘muscle weakness causes pain’ and ‘stiff joints not good, therefore let’s get the joint moving. Though it is unclear how precisely exercise improves pain, we have new evidence that points us to a ‘top-down’ approach... ( I have explained it below…)

Most of the studies are done on healthy young painless adults, but the results are still encouraging.

EIH is mediated by multiple mechanisms. The most studied mechanism is the endogenous opioid system.

Our brain has its own ‘pharmacy’ which can secrete potent pain killers like opioids (beta endorphins). When muscles contract during physical activity, nerves in our body can signal that ‘pharmacy’ in our brain to release our in-built pain-relieving substance.

PAG and RVM are important parts of the ‘pharmacy’ in the mid-brain that is associated with this opioid-dependent descending inhibitory mechanism (a mouthful isn’t it)- this type of pain modulation is called ‘top -down’ pain modulation system, because it is coming from the brain.

Another potential mechanism is H-P-A (hypothalamus-pituitary-axis) all in the brain – an exercise is a form of stress to our body that activates the H-P-A axis and the autonomic nervous system in our body. This releases stress hormones like adrenalin and cortisol which activate areas in the brain to reduce our pain perception.

Another mechanism well-known or easily perceivable mechanism is Conditioned Pain modulation- ‘pain inhibiting pain’.  When we repeatedly expose ourselves to noxious stimuli, adaptation takes place. When we expose our body to rigorous martial art training, we adapt to the stimuli, and eventually breaking a set of bricks may not be a painful experience but an enjoyable one. Some experienced long-distance runners feel ‘euphoria’ in running- ‘Runner’s high’. They may not feel aches and pain from running to the same level as a beginner would feel. It is proposed that our inbuilt ‘pharmacy’ secretes pain killers and other chemicals that make their running an enjoyable experience.  

How much physical activity/exercise should I do?

WHO recommends minimum 2 ½ hours to 5 hours of exercise in a week.

                Moderate-intensity activity causes a slight, but noticeable, increase in breath and heart rate. You can still carry on a conversation.

Vigorous-intensity activity makes you out of breath – you can’t do these activities and chat at the same time.

There is a dose-response relationship between exercise and health benefits, the more you do the more you reap your benefits.

WHO also recommends including simple bodyweight strengthening exercises as there are more benefits from resistance exercises and the recommendation is a minimum of 2 times a week.

What type of exercise?  

Walking or a slow jog is a good place to start.

If you are exercising after a long gap or increasing your duration or never exercised before, you may experience some soreness in your muscles. It is important that you progress slow, spread out your exercise throughout the week, take adequate rest, and hydrate sufficiently.

For example, a beginner workout could be like this:  

i) 30-40 minutes of brisk walk 5 times a week

ii) simple strengthening programs 20 mins session on the days – 2 times a week, on the days you aren’t walking

Physical activity like vacuum your house, walking to shops, taking stairs, cleaning your rooms all count towards physical activity.

Running, Cycling, lifting weights in the gym, yoga, playing a game of sport like football are other options.

Finally…

If you aren’t regularly exercising, starting a new habit, and keeping it up can be extremely hard. I would recommend reading James Clear’s Atomic Habit and I’m seeing some results… so I would suggest,

1.       Make it a ritual – for example, every alternate day at 4:30 PM is my exercise time

2.       Make it attractive- get good running gear, a heart rate monitor, some good music.

3.       Make it very simple- walk for 5 mins, or jog for 2 mins

4.       Focus just on the habit not on the result- if you just focus only on the exercise you will see your distance and time gradually increasing.

That’s all for now.. If you have come this far… thank you for reading.

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I will be sharing my newfound interest in running, I have been running on and off for the last couple of years, but couldn’t keep it up. I don’t call myself a runner yet, but I would like to share how I started and how it’s going.. watch the space.

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