When you’ve got a busy schedule, it’s important to just exercise when you can. But if you have the luxury of choice, is there an optimal one?

You might’ve even heard that exercising at certain times of day can lead to harm.

Norman and Tegan run through the evidence around heart attacks, workouts and what happens when you’re a morning or a night person.

References:

• Association of the time of day of peak physical activity with cardiovascular mortality: Findings from the UK Biobank Study
• Setting your clock: associations between timing of objective physical activity and cardiovascular disease risk in the general population 
• Best Time of Day for Strength and Endurance Training to Improve Health and Performance? A Systematic Review with Meta-analysis 
• Gold, silver or bronze: circadian variation strongly affects performance in Olympic athletes
• Diurnal variation in tennis service
• The effects of exercise session timing on weight loss and components of energy balance: midwest exercise trial 2 

If you enjoyed this episode, check these out!

• Chronotypes: early birds vs night owls
• Does magnesium work against muscle cramps?
• Norman tried an ice bath so you don't have to

Humans are slightly alkaline – your blood should be a pH between 7.35 to 7.45. Anything outside that range can be life-threatening.

So why are you being told to follow an alkaline diet? Proponents of the diet claim it can tackle everything from osteoporosis to cancer.

Norman and Tegan do a litmus test on the alkaline-acid balance and whether it’s a driver of chronic disease.

References:

• Physiology, Acid Base Balance
• The effect of acid ash and alkaline ash foodstuffs on the acid-base equilibrium of man
• Urine pH is an indicator of dietary acid–base load, fruit and vegetables and meat intakes: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study
• Why is there so much on the internet about the alkaline diet and cancer? – MD Anderson 
• Low-grade metabolic acidosis as a driver of chronic disease: a 21st century public health crisis
• Diet-Induced Low-Grade Metabolic Acidosis and Clinical Outcomes: A Review

If you enjoyed this episode, check these out!

• Why Norman won't shut up about the Mediterranean diet
• Why is the internet telling me to lower my cortisol?
• MSG's messy myths and racist tropes

You’re settling into the couch after a long day, ready to relax with your favourite show … next thing you know, you’re asleep.

What is it about the TV that puts people to sleep, and what can you do to avoid dozing off?

Norman and Tegan explore comfort watching, binge-watching and blue light exposure.

References:

• Exploring the Bob Ross effect: A psychophysiological investigation
• Binge Viewing, Sleep, and the Role of Pre-Sleep Arousal | Journal of Clinical Sleep Medicine
• The inner clock—Blue light sets the human rhythm 
• Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults
• Mitigating the Effects of Blue Light - Sleep Foundation 

If you enjoyed this episode, check these out!

• What is the perfect nap duration?
• Why do you feel so tired after a big meal?
• Is your (artificial) sweet tooth killing you?

If you've seen a physiotherapist, you might’ve undergone needling with the promise it will reduce your pain.

Did you receive dry needling or acupuncture? How can you tell the difference between the two?

Norman and Tegan poke through the evidence to find out how effective these techniques can be.

References:

• Similarities between Ashi acupoints and myofascial trigger points: Exploring the relationship between body surface treatment points 
• Dry Needling versus Acupuncture: The Ongoing Debate
• Acupuncture: Past, Present, and Future 
• Clinical Effectiveness of Dry Needling in Patients with Musculoskeletal Pain—An Umbrella Review 
• Methodological challenges in design and conduct of randomised controlled trials in acupuncture 
• Needling Point Location Used in Sham Acupuncture for Chronic Nonspecific Low Back Pain: A Systematic Review and Network Meta-Analysis
• Comparison of dry needling and trigger point manual therapy in patients with neck and upper back myofascial pain syndrome: a systematic review and meta-analysis
• Acupuncture for Chronic Pain: Individual Patient Data Meta-analysis
• Acupuncture for musculoskeletal pain: A meta-analysis and meta-regression of sham-controlled randomized clinical trials
• Magic tricks are helping scientists understand the placebo effect and pain - ABC News

If you enjoyed this episode, check these out!

• Can you zap yourself buff with electrical muscle stimulation?
• Are office jobs ruining our bodies?
• Is gluten really the enemy?

You might’ve seen headlines about high levels of lead being found in common protein supplements.

With these products becoming more popular, the news has some eager gym-goers concerned about what they’re consuming.

Norman and Tegan discuss how these results compare to our historical exposure – from Ancient Rome to Australia in the 1960s.

References:

• Protein Powders and Shakes Contain High Levels of Lead - Consumer Reports
• Bioaccumulation of lead (Pb) and its effects on human: A review 
• Lead in Food and Foodwares - FDA 
• Low Level Lead Exposure: History and Discovery 
• Lead Toxicity: an Australian Perspective 
• Some US protein powders contain high levels of lead. Can I tell if mine is safe? - the Conversation

If you enjoyed this episode, check these out!

• How much protein do you REALLY need?
• Norman tried an ice bath so you don't have to
• Why do hangovers get worse as we age?

Once you go looking, you realise there are scents in everything – from skincare to cleaning supplies to candles. And of course, perfume.

Are there any implications to our health from taking in natural and synthetic fragrances from all these products?

Norman and Tegan sniff out the evidence when it comes to scent, and whether we should be worried.

References:

• The first chemist in history may have been a female perfumer – here’s how the science of scents has changed since - the Conversation 
• A Smelling Trip into the Past: The Influence of Synthetic Materials on the History of Perfumery
• Health and societal effects from exposure to fragranced consumer products – University of Melbourne
• Effects by inhalation of abundant fragrances in indoor air – An overview 
• Cleaning at Home and at Work in Relation to Lung Function Decline and Airway Obstruction
• Cleaning at Home and at Work in Relation to Lung Function Decline and Airway Obstruction
• Synthetic Endocrine Disruptors in Fragranced Products 
• Do fragrant products like perfume, toilet paper and baby wipes cause cancer? - Cancer Council 
• Characterization of phthalates exposure and risk for cosmetics and perfume sales clerks 
• Chemical exposure and lung function in fragrance industry employees 
• Butter and Plant-Based Oils Intake and Mortality - JAMA

If you enjoyed this episode, check these out!

• Don't sweat it? Conventional vs natural deodorants
• Why is everyone suddenly talking about seed oils?
• Are mobile phones giving us cancer?

Whether you can or not, it feels like a sign of fitness to be able to reach down and touch your toes.

But how important is flexibility when it comes to your physical fitness? Is it a necessary part of healthy ageing?

Norman and Tegan stretch through the evidence on flexibility – when does it count, and how can you achieve it?

References:

• Genetics of Muscle Stiffness, Muscle Elasticity and Explosive Strength
• Genetic associations of body composition, flexibility and injury risk with ACE, ACTN3 and COL5A1 polymorphisms in Korean ballerinas
• Whole-spine dynamic magnetic resonance study of contortionists: anatomy and pathology
• Practical recommendations on stretching exercise: A Delphi consensus statement of international research experts
• The ideal stretching routine – Harvard Health
• How stretching actually changes your muscles - Malachy McHugh for Ted-Ed

If you enjoyed this episode, check these out!

• Working out? Why 'No Pain No Gain' is bull
• What on earth is grounding?!
• Can you zap yourself buff with electrical muscle stimulation?

You can listen to more episodes of the What’s That Rash? podcast with presenters Norman Swan and Tegan Taylor on the ABC Listen app (Australia) or wherever you get your podcasts. We answer your questions on everything from TikTok wellness trends to wonder drugs and diet myths.

The battle between butter and margarine has been happening since margarine was invented in the 19th century.

So have we figured out which one is better for your health – butter with its high saturated fat content, or margarine which is an ultra-processed food?

Norman and Tegan unpack the winding history of this debate from its inception to the present day.

References:

• The Butter Wars: When Margarine Was Pink – National Geographic 
• The Butter-Margarine Controversy - 1946
• What the margarine vs butter argument says about nutrition – University of Melbourne
• Dietary fats - Healthdirect 
• What’s better, butter or margarine? - Diabetes Australia 
• Serum cholesterol response to replacing butter with a new trans-free margarine in hypercholesterolemic subjects
• Individual Cholesterol Variation in Response to a Margarine- or Butter-Based Diet: A Study in Families
• Effects of margarines and butter consumption on lipid profiles, inflammation markers and lipid transfer to HDL particles in free-living subjects with the metabolic syndrome
• BMI modifies the effect of dietary fat on atherogenic lipids: a randomized clinical trial
• From margarine to butter: predictors of changing bread spread in an 11-year population follow-up
• Association between dairy intake and multiple health outcomes: a scoping review of systematic reviews and meta-analyses | European Journal of Clinical Nutrition 
• Umbrella Review of Systematic Reviews and Meta-analyses on Consumption of Different Food Groups and Risk of All-cause Mortality - ScienceDirect

If you enjoyed this episode, check these out!

• Is emu oil the new snake oil?
• Is daylight saving time bad for us?
• Should you be avoiding nightshades?

You can listen to more episodes of the What’s That Rash? podcast with presenters Norman Swan and Tegan Taylor on the ABC Listen app (Australia) or wherever you get your podcasts. We answer your questions on everything from TikTok wellness trends to wonder drugs and diet myths.

Do you ever wonder while you’re shampooing and conditioning – is this really necessary?

The no-poo movement encourages people to ditch their products and turn to homemade concoctions, or nothing at all.

Norman and Tegan rinse out the evidence for and against hair care, and how we got here in the first place.

References:

• Clean: A History of Personal Hygiene and Purity
• Shampoo and Conditioners: What a Dermatologist Should Know?
• The "No-poo" Craze: What do Gwyneth Paltrow, Kim Kardashian, Adele and Howie Mandel have in common? They don’t "poo" - McGill University
• Essentials of Hair Care often Neglected: Hair Cleansing
• Unlocking the secrets of the hair microbiome: From scalp health to therapeutic advances
• Parabens in Cosmetics - US Food and Drug Administration

If you enjoyed this episode, check these out!

• Can you get away with skipping your daily shower?
• Which hair loss treatments actually work?
• Does magnesium work against muscle cramps?

You can listen to more episodes of the What’s That Rash? podcast with presenters Norman Swan and Tegan Taylor on the ABC Listen app (Australia) or wherever you get your podcasts. We answer your questions on everything from TikTok wellness trends to wonder drugs and diet myths.

It’s marathon season, but whether you’re running 40 kilometres or four you might’ve wondered what it’s doing to your joints.

It used to be thought things like osteoarthritis of the knee or the hip were caused by wear and tear, and running made things worse.

Norman and Tegan jog through how the evidence has evolved, and answer the question: should you be hopping on the run club trend?

References: 

• Running and your knees - ABC listen
• Effects of Running on the Development of Knee Osteoarthritis: An Updated Systematic Review at Short-Term Follow-up
• The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis
• The risk of osteoarthritis with running and aging: a 5-year longitudinal study. - Abstract
• Can marathon running improve knee damage of middle-aged adults? A prospective cohort study
• How much running is too much? Identifying high-risk running sessions in a 5200-person cohort study
• Using metformin to treat knee osteoarthritis - ABC listen
• Changing the brain to reduce pain and walk the Camino - ABC listen
• Metabolic syndrome meets osteoarthritis | Nature Reviews Rheumatology
• Mechanical loading and orthobiologic therapies in the treatment of post-traumatic osteoarthritis (PTOA): a comprehensive review
• Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk

If you enjoyed this episode, check these out!

• Is sitting the new smoking?
• Sweaty sauna bathing for better health
• Is being an Olympian bad for your health?

You can listen to more episodes of the What’s That Rash? podcast with presenters Norman Swan and Tegan Taylor on the ABC Listen app (Australia) or wherever you get your podcasts. We answer your questions on everything from TikTok wellness trends to wonder drugs and diet myths.