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Ice baths or (cold water immersion) are recovery tools which have long been used in professional sports, particularly in sports such as tennis where recovery is vital with short turnaround times in between matches and tournaments. Ice bath use is now on trend in the general population as individuals look for the same recovery benefits of athletes. In this blog, Melbourne sports chiropractor Dr. Nicholas Shannon explores the theory behind ice baths, whether they provide any real benefit and identifies the optimal temperature and duration one needs to spend in an ice bath, as not all ice baths are the same

What Is Cold Water Immersion?

Cold water immersion (CWI) has been around for decades and as the name implies, it is the process of immersing the body in cold water, usually 15 degrees celsius or less for 5 to 20 minutes following intense exercise, in an attempt to attenuate the stress and damage the body undergoes during exercise, to aid in a faster recovery, to mitigate fatigue and optimize performance.

Intense exercise results in physiological changes and damage to the body including muscle damage, oedema, hyperthermia, dehydration, glycogen depletion and tissue inflammation. The proposed effects of CWI have been attributed to hydrostatic pressure and/or reductions in body tissue temperatures which impacts tissue blood flow (vasoconstriction), post exercise fluid retention and metabolic activity. This may accelerate the recovery process by reducing muscle tissue damage, swelling, inflammation, muscle spasm pain and thermal stress.

The Effects of CWI on Performance

At a high level view, it would appear that sitting in an ice bath after exercise for a few minutes will lead to faster recovery, reduce inflammation, muscle soreness and fatigue, as well as improved performance. However, the literature paints a more complex picture which can be situation and dose-response dependent. Furthermore, there is wide variability in testing protocols used to examine CWI (temperature of the water, duration of time spent in the water, follow up time points analysed, exercise interventions etc) making it more challenging to pool data in the quest for more accurate findings.

Inflammation and Cold Water Immersion

In terms of reduction of inflammation within skeletal muscle the evidence is mixed. One study suggests CWI is no more effective than active recovery (slow, warm-down) for minimizing inflammation and the stress response following resistance exercise. Moreover, a 2017 study examining CWI and whole body exposure following a marathon found similar results which showed CWI was no more effective than active recovery. While a 2023, meta-analysis showed that CWI reduces inflammatory markers including creatine kinase (CK), interleukin 6 (IL-6) and lactate at 0, 24 and 48 hours post exercise, which is consistent with other studies; although CWI did not produce any effect on CK or IL-6.

Resistance and Aerobic Performance and Cold Water Immersion

A 2020 systematic review and meta-analysis found regular use of CWI following resistance training had a negative effect on maximal strength and strength endurance, this included 1RM, maximal isometric strength, strength endurance, and ballistic efforts which were all reduced following CWI. This is reported to be due to the effects of cooling on myogenesis (new muscle formation) which negatively impacts skeletal muscle strength and growth development, therefore blunting the tissue adaptation response to resistance training. Additionally, the paper found CWI did not impact performance gains associated with aerobic training.

A 2022 systematic review and meta-analysis found CWI was effective in promoting recovery in muscle power after eccentric exercise at 24, 48 and 72 hours; CWI was effective in promoting recovery in muscle power 24 hours after high intensity exercise. However, CWI was not effective in recovering muscle strength at 24 hours following either eccentric exercise or high intensity exercise, lending some additional support to the notion that cooling blunts myogenesis.

Interestingly though, a 2023 systematic review and meta-analysis looking at the effects of CWI on the recovery profile of physical performance conversely found CWI impairs muscle power production 1 to 6 hours post CWI. Furthermore, their analysis showed CWI was effective in the recovery of muscle strength 24-48 hours post following endurance exercise, again in contrast to the two prior review papers. Their findings on CWI recovery following endurance performance was consistent with the 2020 and 2022 reviews within 1 hour of exercise showing reduced perceived fatigue and soreness, thermal and cardiovascular strain.

Flexibility, DOMS, CK Levels and Cold Water Immersion

Additionally findings from the 2022 review paper found,

CWI had no effect on the recovery from flexibility performance
CWI was effective at recovery from delayed muscle onset soreness (DOMS) at 48, 72 and 96 hours following eccentric exercise and was moderately effective in reducing DOMS following high intensity exercise at 24 and 48 hours
CWI was not effective at 24 hours in reducing perceived recovery with a small effect at 72 and 96 hours post eccentric exercise. It was however effective at 24 hours post high intensity exercise
In reducing CK levels following eccentric exercise CWI was only effective after 7 days, but was effective at 24 and 48 hours following high intensity exercise
The CK findings were supported by the 2023 review paper, which found a reduction in CK levels following endurance exercise at 24 to 72 hours.

Making Sense of the Literature

Cold Water Immersion and Aerobic Exercise

It is important to note the variability in study designs brings with it the risk of biases which can influence the results. That being said, there are some areas where the literature appears to be slightly more consistent and other areas where the literature is mixed. In terms of recovery from endurance or high intensity exercise there is a more consistent picture that CWI is beneficial for recovery. Endurance or high intensity training is more representative of athletic training and often involves high volumes of running which results in the greatest rise in CK levels and therefore muscle damage in the lower limb, potentially one explaination for why CWI may be beneficial.

Cold Water Immersion and Resistance Exercise

The picture is less clear with respect to resistance training with mixed data on the recovery of both power and strength following eccentric (resistance) training and the overall effects of CWI on blood inflammation markers. With evidence to suggest CWI attenuates the physiological adaptation responses to resistance training (ie. muscle hypertrophy, strength, power) and no evidence indicating CWI is beneficial or augments the adaptative responses to strength training.

It makes recommending ice baths following resistance exercise with short turn around times between sessions less robust, particularly if the focus of the sessions are strength gains and hypertrophy. There may be resistance training subgroups who might benefit from CWI, such as chronically trained elite athletes or during periods of high training loads, where the focus is on short-term recovery rather than physiological adaptations.

Optimal Cold Water Immersion Time and Temperature

Finally, the burning question on most readers’ minds no doubt will be, “what is the optimal immersion time and temperature?”. Two papers looked specifically at the optimal timing and temperature for CWI which indicated 11-15 degrees celsius water temperature, for 11-15 minutes of immersion provided the best results for both immediate and delayed effects. While those undertaking high intensity training should look for a shorter duration, at a lower temperature for optimal results.

Final Thoughts On Cold Water Immersion

In summary, based on the current state of the literature CWI following endurance exercise appears to be beneficial for recovery and could be considered as part of an overall recovery plan. However, with mixed data on the recovery benefits following resistance exercise, coupled with evidence suggesting CWI may have a physiological blunting effect on muscle adaptation following resistance training, CWI would best be considered on an individual basis and may not be beneficial in all cases following resistance training.

Optimizing training and athletic performance involves a raft of different strategies including ice baths, mental imagery, sleep, nutrition. We have you covered with blogs on the importance of all of these. Additionally, we recommend regular treatment including remedial and sports massage to help keep your body fresh. If you would like to make a remedial massage or sports chiropractic appointment, you can book on the link below. Our sports chiropractic clinic is centrally located on the corner of Swanston Street and Collins Street, in the CBD of Melbourne.

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Nicotinamide Mononucleotide (NMN) is a supplement that seldomly comes onto most people’s radar, yet it is a supplement that holds a promising future with some researchers suggesting NMN should become a staple supplement to help improve longevity. Melbourne sports chiropractor Dr. Nicholas Shannon takes a look at literature on NMN to see if it is something you should consider.

What is NMN and How Does NMN Work?

NMN is synthesized in the body via two pathways, the Salvage and Preiss-Handler pathways, with the former synthesizing NMN from vitamin B3. Once synthesized, NMN acts as a precursor to a metabolic coenzyme called NAD+ (nicotinamide adenine dinucleotide).

NAD+ is an important coenzyme involved in a variety of processes including cell death, aging, gene expression, neuroinflammation and DNA repair.

NMN is found naturally in plant and animal sources including soybeans, broccoli, avocado, tomatoes, cucumbers, mushrooms, raw beef and shrimp. The levels of NMN in these food sources vary from around .25mg/100g to 1.88mg/100g. For comparison, studies investigating the efficacy of supplementing with NMN range from 250mg to 2000mg per day.

Why is NMN and NAD+ important in aging?

As we age there is a reduction in energy production in the mitochondria (the power factory of cells) in a variety of organs including the brain, adipose tissue, skin, liver, skeletal muscle and pancreas as a result of decreased NAD+ levels. This depletion of NAD+ occurs naturally with aging, due to an increase in consumptions of NAD+ consuming enzymes. Additionally, the metabolic pathway which produces NAD+ can be inhibited by chronic inflammation, high fat diets and, oxidation which can further negate the levels of NAD+ in the body. This in part, leads to biological changes associated with aging such as, reduced endurance, strength, cognitive impairment and DNA damage.

Supplementation with NMN has been shown to boost NAD+ levels by 2-3 times. Furthermore, fasting, and reducing energy intake may also improve NAD+ levels. It is for this reason, NMN supplementation research has moved from NMN being a source of cellular energy and a precursor to NAD+, to it’s potential impact on other disease such as age-induced type II diabetes, obesity, cerebral and cardiac ischaemia, heart failure and cardiomyopathies, Alzheimer’s disease (AD) and other neurodegenerative diseases, corneal injury, macular degeneration and retinal degeneration and acute kidney injury.

Safety and Efficacy of NMN

NMN has been extensively studied in mice and rodents, where results have shown significant improvements across a variety of areas including AD, age-related physiological changes, as well as renal, cardiac, vascular and skeletal muscle function. However, impressive results in animal studies do not necessarily correlate to the same changes in humans.

The first step in the human trial process is to establish if an intervention is safe, efficacious (does it work) and if are there any adverse reactions. To this author’s knowledge, there are at least 9 randomized controlled human trials which have explored dosage ranges from 250mg to 2000mg per day, over various time periods ranging from 30 days to 3 months, across a variety of groups; healthy middle aged adults, healthy older aged adults, recreational athletes, obese and overweight, males and females.

These studies have consistently shown NMN is safe and well tolerated. The data is favourable to seeing an increase in NAD+ concentrations in the blood, however it should be noted there have been some studies which haven’t shown a statistically significant change. Furthermore, it should be noted that currently there is no agreed definition of what low, normal or high NAD+ levels are.

Reported Benefits of NMN

A 2023 randomized, controlled, double blinded placebo trial (the gold standard study design) investigating the effects of NMN at 300mg, 600mg and 900mg versus placebo on a cohort of 80 healthy male and female adults over 60 days, found increased blood concentrations of NMN, significantly improved 6 minute walking test (endurance), minimal to no change in blood biological age, and improved health scores (SF-36 questionnaire) in the NMN groups compared to placebo. In addition to NMN being safe and well tolerated across all doseage levels.

Additional clinical trial data has shown the following.

Sleep – no detectable changes in sleep quality scores
Physical activity (older adults) – significantly improved gait speed, grip strength, 30s chair-stand test indicating a potential prevention in age-related muscle decline
Physical activity (middle-aged adults) – significantly increased oxygen consumption in ventilation and energy consumption. In addition to significantly improved aerobic capacity when exercise and NMN were combined, suggesting NMN could be used to improve athletic performance
Nervous system-related – improvements in hearing in older adults, no change in cognition or vision
Diabetes – improved muscle insulin sensitivity which may improve impaired glucose tolerance
Anti-aging – significant improvement in telomere (a biomarker for monitoring aging)

Where To From Here?

The early human data for NMN looks promising, it’s safe, it is well tolerated, and there is evidence in adults that NMN may play an important role in anti-aging. The data specifically related to improvement in endurance and strength for older and middle-aged adults looks extremely promising, and this should be an area of great interest to those in the sports and exercise medicine field.

Overall, the early data suggests NMN might have a bright future, which will be solidified as more data comes out. Some of that data needs to provide clarity to understand the full impacts of NMN supplementation on the body; to establish agreed measurements of NAD+ to determine what are low, normal and high levels; to identify if there are specific age-related dosages; and to study the safety of NMN supplementation over the long term (years).

It is also important to note that supplementation is only one component to improving health and longevity. Additionally sleep, diet, fasting and exercise are essential to the process.

If you are interested in exploring the benefits of NMN for yourself, Melbourne sports chiropractor Dr. Shannon has analysed the market providers and prefers Renue by Science, as their products are third party tested to confirm their supplements purity, and their manufacturing plant is FDA approved. To read more about why third party testing is important for supplements have a read of our blog on sports supplements.

If you would like to book an appointment a chiropractic or massage appointment at our Melbourne city chiropractic clinic on Collins Street in the Melbourne CBD, click on the link below.

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The COVID-19 pandemic created global disruption, uncertainty and with many countries enforced society into lockdowns, which made physical activity and exercise more onerous and challenging. However, one of the few exceptions to the lockdown rules was exercise, so Melbourne city chiropractor Dr. Shannon examines the evidence on exercise and immune function.

Does Acute Bouts of Intense Exercise Help or Hinder Immunity?

It is well known that regular bouts of exercise lasting up to 45 minutes of moderate to vigorous exercise is beneficial for immune defence, particularly in older adults and those with chronic diseases. This type of exercise is beneficial for the normal functioning of the immune system and is likely to help lower the risk of respiratory infections/illnesses. However, there is debate within the scientific community whether acute bouts of vigorous intensity exercise leads to a period of immune suppression post exercise.

There has been a long held concept in exercise immunology developed in the 1980s and 1990s called the “open window” hypothesis which proposes a J curve relationship between exercise intensity and infection risk. Which is supported by the belief that athletes who engage in high volume endurance training experience a greater incidence of Upper Respiratory Tract Infections (URTI) compared to those who are less active. Until recently this concept has remained relatively unchallenged.

The “open window” Hypothesis

The “open window” hypothesis suggests that following a prolonged (>1.5hr) and vigorous acute bout of exercise or following chronic intense training (>1.5hr on most days) there is an “open window” which results in an increased risk of opportunistic infections such as URTI’s. The three principles underpinning this concept are:

1). Infection risk increases after prolonged vigorous aerobic exercise

2). Acute bouts of vigorous exercise can lead to temporary reductions in salivary immunoglobulins resulting in higher risk of opportunistic infections

3). A period of post exercise reduction in peripheral blood immune cells resulting in a period of immune suppression.

J Curve – relationship between the risk of infection and level of exercise intensity

Is The “open window” Hypothesis Still Relevant Today?

Recently though there has been emerging evidence suggesting this concept may be outdated. There is evidence, albeit small that indicates international athletes suffer from less URTI than national athletes. This raises the likelihood that infection susceptibility is more likely multifactorial including genetics, sleep, stress, nutrition, travel, circadian misalignment and increased exposure risks due to close proximity of crowds rather than being directly attributed to acute or chronic bouts of vigorous training. This also indicates that international athletes are potentially better supported, have access to better education helping them to improve their life-style behaviours over national athletes resulting in lower risks of infection.

Secondary to this, evidence supports the opposite of the three principles upholding the “open window” concept. With no changes seen in mucosal immunity which has previously been flagged as an indication of immune suppression. The reduction in blood immune cells (primarily lymphocytes) 1 to 2 hours post exercise reflects a transient and time dependent redistribution of immune cells to peripheral tissues resulting in a heighten state of immune surveillance and regulation leading to enhanced antibacterial and antiviral immunity, not suppression of the immune system.

Moderate to Vigorous Exercise Is Beneficial for Immunity

Further research is needed to confirm or refute the “open window” concept however, it currently appears that the infection risk post vigorous exercise is more likely to be associated with a multitude of other factors rather than purely post exercise immune suppression. So for athletes and non-athletes the message remain the same, regular moderate to vigorous exercise is beneficial to enhance immune function to reduce the risk of bacterial and viral infections including URTI’s. And remember that good hygiene practices (washing hands regularly, not touching your face), physical distancing, getting good quality sleep, reducing stress levels and eating healthy wholefoods are the keys keeping your immune system in peak condition. To read more on the importance of sleep you can find the Shannon Clinic Melbourne Chiropractic and Sports Care blog on sleep and performance here.

As a Melbourne city sports chiropractor Dr. Shannon advocates to all his patients the important of regularly exercise and utilizes exercise therapy with all patients. To work out what exercise is best, moderate continuouse or high intensity interval training check out our blog. If you are looking for an active way to rehabilitate your musculoskeletal injury book an appointment today at our Melbourne CBD chiropractic clinic on Collins Street in the Manchester Unity building opposite the Melbourne Town Hall and City Square.

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Ketogenic diets or low carbohydrate diets routinely appear in the media with stories ranging from the negative health implications they can have including reduced bone health to the benefits they have on weight loss, diabetes and performance in elite athletes. With such conflicting information out there, Melbourne city chiropractor Dr. Shannon uses his knowledge and experience in addition to reviewing the literature to see what the truth is about ketogenic diets and performance.

What Is Keto?

For a diet to be considered ketogenic it needs to contain less than 50g of carbohydrates (CHO) per day, be high in fats 70-80%, with the remaining 15-25% coming from protein. For athletes, especially endurance athletes CHO’s are the preferred fuel source for enhancing performance therefore by restricting CHO intake it forces the body into ketosis. In a ketosis state, ketone bodies (fat molecules) are released from the liver, producing an alternative fuel source to CHO’s.

Why Athletes Choose a Keto Diet

The utlization of fats as fuel becomes one of the primary reasons endurance athletes are attracted to ketogenic diets. This attraction occurs because fats provide a better source of energy than carbohydrates and there is an abundance of fat stores compared to the limited glycogen (CHO) stores in the muscles. Other reasons athletes are attracted to ketogenic diets include, the feeling of enhanced recovery, improvements in body composition and reduced post exercise inflammation.

It is well documented that ketogenic and low CHO diets are beneficial for body composition changes, namely weight reduction through decreases in adipose (fat) tissue. This isn’t surprising considering fat oxidation (fats being burned for fuel) becomes the primary energy source in a ketogenic diet.

Keto Diets and Athletic Performance

In terms of athletic performance the evidence is less clear. Majority of the current studies looking at athletic performance and ketogenic diets routinely involve small sample sizes of elite athletes and over a short time frame (3-10 weeks). As a result, any findings from these studies need to be interpreted and considered with other available literature. With such a specific cohort (study population) transferability of the results to other non-elite athletes becomes difficult.

Exercise Capacity

In terms of endurance performance, there appears to be a reduction in performance during high intensity bouts above 70% of VO2Max when on a short term (3-10 week) ketogenic diet. The postulated causes include; fats require greater oxygen uptake and energy to be broken down compared to CHO, possible impaired glycogen metabolism at higher intensities. However, one study which looked at endurance athletes who were on ketogenic diets for longer than 6 month showed no changes in muscle glycogen stores.

Resistance Training

For resistance training and lean muscle mass it appears that ketogenic diets result in reduced body mass, with conflicting evidence on whether it impacts on lean muscle mass. Regardless, it doesn’t appear to negatively impact strength.

Bone Health

Bone health is an interesting area. An Australian study published early this year revealed that bone resorption (break down of bone) increased and bone formation (new bone formation) decreased in elite athletes (race walkers) while on a short term (3 – 3.5 week) ketogenic diet. This study received a lot of press because the implications are potentially serious; ketogenic diets leading to reduced bone mineral density and bone injuries in elite athletes. However, this study needs to be put into context. It looked at elite race walkers, predominantly males who were on short term ketogenic diets. This is a very specific subgroup of people. As the study rightly points out, further research is needed to understand these findings further before any definitive answer is known about ketogenic diets (short and long term) and bone health in elite athletes and in the general population.

The Wash Up

When it comes to athletic performance ketogenic diets improve fat oxidation and reduce body mass, which is important in endurance sports and weight-class based sports such as boxing, weight lifting, martial arts etc. They don’t negatively affect exercise capacity at submaximal workloads below 70% VO2Max but they do appear to reduce exercise capacity at high intensities. They may also reduce endurance capacity but this appears to be individual, with some athletes being affected and others not. At present, finding the right balance of lower CHO levels which are higher enough not to impact performance at higher intensities is the best approach to maximize athletic performance through a ketogenic diet. One final note, even though CHO intake levels are low, this does not mean an athlete will be running a negative energy balance; energy expenditure should always match energy intake.

[Click Through To Read About Plant-Based Diets]

As a Melbourne city sports chiropractor with a postgraduate diploma in sports and exercise medicine including nutrition and sports nutrition, Dr. Shannon utilizes diet and supplementation within his wholistic approach to rehabilitation. To book an appointment today with Melbourne city chiropractor Dr. Shannon or sports massage therapists Paula Pena click below. Our Melbourne CBD chiropractic clinic is centrally located on the corner of Collins Street and Swanston Street, opposite the Melbourne Town Hall in the Manchester Unity building.

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Pain is a complex subjective, sensory and emotional experience occurring as a result of damage or potential damage to tissue (skin, ligaments, muscles, bones). Pain is most commonly caused by a specific injury however, in some cases an injury mechanism is absent.

Types of Pain (Simplified)

There are three different types of generalised pain:

Nociceptive Pain

Nociceptive pain occurs when there is damage to a tissue (like burning your finger). This pain can be local or it can be referred (ie. the pain is felt away from where the tissue is damaged). An example of referred pain is, “sciatic” leg pain which is associated with tissue damage in the lower back.

Neurogenic Pain

Neurogenic pain occurs when the nerves behave abnormally by conducting nociceptive pain where there is no apparent tissue damage or pain source.

Psychogenic Pain

Psychogenic pain arises from the mind (such as the memory of a bad past experience).

Nociceptive Pain (Peripheral Pain)

Nociceptors are sensors found in the body which detect the possible threat of injury or actual injury to tissues such as bone, ligaments, skin etc. They then relay this information to the central nervous system (CNS) – spinal cord.

There are two types of nociceptive fibers, C fibers and A delta fibers which respond to different sorts of pain stimulation.

A delta fibers carry signals from the body’s periphery (such as the fingers or feet) back to the CNS very quickly and are responsible for the acute pain experienced when a tissue has been injured.
C fibers carry signals more slowly from the periphery to the CNS and are responsible for sub-acute/chronic pain.

Sensitisation

When a tissue has been injured, the nociceptive fibers become sensitised. As a result, the nociceptives threshold for activation and subsequently sending pain signals back to the CNS is much lower. For example, following a bump on the head a light touch to the injured area will be painful. In the case of chronic pain, abnormal sensitisation of nociceptors contributes to why pain is easily triggered, why the pain is often disproportionate to the trigger and why pain is felt long after the initial injury stimulus has gone.

Spinal Cord and Brain Involvement

The information carried by the A delta and C fibers is then transmitted back into the CNS where it is processed in a part of the spinal cord called the “dorsal horn”. The dorsal then determines whether the information needs to be relayed up the CNS to a higher brain centre for processing and response. Or, it may determine the response can occur locally from the dorsal horn, called a “spinal reflex response”. An example of this would be the inflammatory reponse following an injury involving muscle spasm and increased blood flow.

Managing Pain

Non-pharmaceutical Interventions

Chiropractic adjustments are postulated to manage spinal pain by affecting the higher brain centre, the nocipetive fibers in the periphery of your body and through the spinal cord reflex response.

Acupuncture or dry needling is another treatment intervention for managing pain. Needling affects pain at the periphery by desensitizing the nociceptive fibers so they are not stimulated as easily, while also triggering a local muscle relaxation response.

Exercise therapy and physical activity is another intervention that is beneficial in the management of pain, including pain associated with musculoskeletal conditions like osteoarthritis and low back pain.

These are all interventions Melbourne city chiropractor Dr. Shannon utilizes at The Shannon Clinic Melbourne Chiropractic and Sports Care use as a part of our holistic approach to patient care.

Read more about Melbourne sports chiropractor Dr Nicholas Shannon. [Click through to About the Shannon Clinic page]

Pharmaceutical Interventions

Pain medication (analgesics) such as paracetamol (Panadol), ibuprofen (Nurofen) and diclofenac (Voltaren) work on desensitising the A delta and C fibers and hence reducing pain at the source (in the periphery). Pain medications which are codeine based (Opioids) like Panadeine work by affecting how the body interprets pain in the higher brain centres (centrally, rather than peripherally).

It is important to remember when taking pain medication that long term use of analgesics can have harmful side effects like gastric ulcers, renal disease and cardiovascular disease. In addition to this there is strong evidence indicating paracetamol and NSAID’s are ineffective in the treatment of low back pain.

If you are interested to learn more about the different types of regional pain such as the common causes of neck pain or hip pain, you should find our blog on these topics of interest. If you would like to make an appointment to see Melbourne city chiropractor Dr. Nicholas Shannon or remedial massage therapist Paula Espinoza you can book below. Our Melbourne city chiropractic clinic is located on Collins Street in the Melbourne CBD, with easy access via trains at Flinders Street Station, trams via Collins, Swanston, Bourke and Elizabeth Streets and parking at Federation Square.

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The Benefits of HIT/HIIT Training

Exercise and physical activity are extremely important for our overall health and wellbeing. With evidence showing physical activity improves; quality of life, sleep, cognition, physical function, insulin sensitivity, while reducing the risks of; clinical depression, dementia, a raft of cancers and chronic preventable diseases, as well as anxiety, blood pressure, weight gain and falls. You can read more about the benefits of physical activity in Melbourne city chiropractor Dr. Shannon’s article on Exercise Medicine.

The current recommendations for physical activity are for 150 minutess per week of moderate to vigorous exercise, this means exercising to an intensity where it is still possible to maintain a conversation but with difficulty. High intensity (with/without intervals) training is a great way of efficiently reaching that 150 minutes per week mark with a host of added benefits.

High Intensity Training (HIT) / High Intensity Interval Training (HIIT)

HIIT refers to exercise that occurs in frequent short burst or “sprints” of high intensity exercise, with recovery periods. The sprints can last from 30 seconds to 4 minutes, with recovery periods lasting anywhere from 1 to 4 minutes and repeated sprints of 2 to 6 cycles per session. For true HIIT to be achieved, heart rate (HR) needs to reach 85-90%+ of max HR during the sprint effort. This is the key difference with moderate continuous training (MCT) where HR will only reach 60-70% of max HR.

Why HIT/HIIT?

In healthy individuals HIT/HIIT programs have been clearly shown enhanced exercise capacity, muscle strength and muscle oxidation compared to MCT. It may also improve cardiovascular fitness and function, as well as anxiety and depression severity. It has been associated with improvements in these same variable in individuals with cardiovascular disease, spinal arthritis and multiple sclerosis, in addition to reducing the disability associated with these diseases.

In obese and overweight individuals it is as effective in the short-term as MCT at modest reductions in body fat and waist circumference, which suggests it may be a more time efficient way to exercise. Additionally there is also evidence showing it is well tolerated and has greater improvements in disability and exercise capacity in individuals with nonspecific low back pain when compared to MCT.

What Type of HIT/HIIT Program?

One of the appealing features of HIIT programs are how time efficient they are, especially when compared to MCT. In addition to this, HIIT programs appear to result in similar or greater endurance performances and VO2max (a measure of fitness) when compared to MCT.

Cardiovascular protocols utilizing short intervals (30 seconds or less), for 5 minutes or less, performed 4 or fewer times per week will assist in developing VO2max in the general population. However, the greatest improvements come from longer sprint intervals (2 minutes or longer), higher volume (15 minutes or longer) over a longer duration (4-12 weeks). Resistance training HIT protocols are typically defined as more than 70-80% of a 1 repetition maximum, performed at a maximum of 1 set of 12 repetitions.

Finally, for anyone considering a HIIT program it is important to note that even though HIIT appears to be safe for most individuals, consulting a health/medical practitioner to determine if a HIIT program is safe for you is extremely important before you start any HIIT program.

To book an appointment with Melbourne city sports chiropractor Dr. Shannon or remedial massage therapist Paula Pena you can book below. You will find our Melbourne chiropractic clinic located on Collins Street in the Melbourne CBD opposite the Melbourne Town Hall.

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