Exercise and Osteoarthritis
Which exercise is best for Osteoarthritis?
Banana Resistant Starch Effects on Gut Microbiome, Obesity and Metabolic Syndrome
Gut microbiome: influencing factors
Did you know that close to 1.5kg of bacteria (microbiome) exists in our gut? The composition of the gut microbiome is closely related to the health of its host. For example, obesity is related to gut microbiome dysfunction, in other words, with extra weight, the gut microbiome changes in structure and function.
Our gut microbiome is influenced by age, the environment in which we live and lifestyle habits. Factors such as poor nutrition, medications, stress and physical inactivity can negatively impact the gut microbiome. However, we can positively influence the gut microbiome composition through healthy nutrition, including resistance starch.
Resistance starch is the sum of products resulting from starch degradation that are not absorbed in the small intestine. It is considered a prebiotic; these prebiotics then feed probiotics. Once such example is banana resistance starch (BRS) found in green bananas.
What does the research say?
Rats fed 2.5g/kg of BRS for 6 weeks decreased their body weight by an average of 9%. These rats did not change their food intake; BRS supplementation was the only difference between study groups pre and post intervention.
In rats fed a high fat diet, those who took BRS improved their gut diversity and structure, by upregulating Bacteroides/Firmicutes ratio and other gut species associated with reducing levels of glucose, triglycerides, LDL-C (bad cholesterol) and insulin. Furthermore, BRS improved functioning of hormones associated with food intake and control (i.e., ghrelin and leptin).
Where to from here?
Need to test in humans! In the interim, eat more green bananas or add some green banana flour to your recipes. Check out this recipe for a start: https://www.naturalevolutionfoods.com.au/blueberry-spice-muffins/
Dementia and Daily Step Count Association
Dementia impacts close to half a million Australians. The number of people living with dementia is set to double in the next 25 years. Whilst there are many factors that contribute to dementia, a recent large study in the UK has highlighted how walking/step count may be one factor that can reduce the risk of being diagnosed with dementia.
Study objective: investigate association between all-cause dementia and daily step count
Participants: 78,430 UK adults (average age 61.1 years) - 45% male, 55% female
Measure: daily step count (via accelerometer, incidental steps (40 steps per minute), peak 30-minute cadence, incidence of dementia (7 year follow-up).
Findings: An average of 3577 steps per day had a 25% reduction in dementia incidence, whilst an average of 9826 or more steps each day equated to a 50% reduction in dementia incidence!
Summary: a higher number of steps each day is associated with a lower risk of all-cause dementia, but some is still better than none. Even more reason to aim for 10,000 steps each day.
Source and further reading: doi:10.1001/jamaneurol.2022.2672
Caffeine: Friend or Foe?
Do you enjoy a cup of coffee each day, or are energy drinks more your thing? The following blog article summarises the latest research regarding the health benefits and negative effects associated with caffeine consumption.
The average coffee consumption is around 135mg/day. One cup or one teaspoon of coffee has approximately 70-140mg of caffeine.
It takes around 45 minutes for the caffeine we have ingested to reach the blood stream, and approximately 2.5 to 4.5 hours to be metabolised. Smoking can increase the removal of caffeine from the blood stream, whereas pregnancy and some medications (included anti-depressants, antibiotics and contraceptives) slow removal.
- Benefits of caffeine:
Decreases fatigue, and increases alertness and reaction time
- Decreases appetite and may reduce weight gain
- May decrease risk of depression
- 2-5 cups per day associated with reduced risk of Type II diabetes, some cancers and Parkinson's disease
- 3-6mg/kg 1 hour before exercise may improve performance (effect vary based on genetics, daily caffeine habits, gender, fitness status and time of day)
- Can positively influence gut microbiome and health metabolite production, and can increase intestinal motility and transit time (i.e., helps you poo)
Negative effects of caffeine:
- >1200mg per day can cause agitation, severe anxiety, inability to sleep, elevate blood pressure, palpitations
- Combined with alcohol can cause death
- Avoid >200mg if pregnant (associated with lower birth weight)
Sources and further reading: doi:10.1001/jama.2021.21452; doi:10.3389/fspor.2020574854, doi:10.3390/nu12051287
Fibre intake, gut health and exercise capacity
It's been a while between posts, but we thought we kick things off again with a summary of Camilla's final published paper from her PhD.
The gut microbiome has been associated with cardiorespiratory fitness (CRF) possibly via metabolites produced during short-chain fatty acid (SCFA) fermentation. Soluble fibres, such as oligo-fructose enriched (FOS) inulin, increase SCFA fermentation.
Can an increase in soluble fibre intake improve CRF?
20 inactive but healthy adults were recruited to one of two groups.
- Group 1: 6 weeks of high intensity interval training (HIIT) + 12g of FOS-inulin each day
- Group 2: 6 weeks of HIIT + 12g placebo (maltodextrin) each day.
Each participant complete a VO2max (measures CRF) test and provided a stool sample before and after the intervention.
FOS-inulin did not improve CRF response to HIIT. Participants who had a greater CRF response to training had a larger abundance of B.uniformis species and gellen degradation pathways. However, FOS-inulin improved ventilatory thresholds (lactate accumulation and threshold), which was associated with a greater increase in Bifidobacterium taxa, acetate (SCFA) production and processes involved in energy production and usage.
FOS-inulin may be a beneficial ergogenic aid in endurance exercise. A B.uniformis probiotic could improve CRF......these thoughts need further exploration.
Source and further reading: https://pubmed.ncbi.nlm.nih.gov/34910161/
Review: Resistance Exercises for Running Improvement
Are you a runner? Make sure you include some strength training!
One way to improve endurance performance is to improve running economy. Running economy is how much oxygen is used at a given speed. Less oxygen used = better performance overall.
Heavy loading strength training (85% maximum effort), moderate loading (40-70% of maximum effort), plyometrics and explosive strength training (or a combination of these) can improve running economy up to 8% without affecting body mass.
- What does the research say about injury prevention? There is a general trend to indicate:
- Strengthening the ankle-foot complex can improve ability to cushion contact forces
- Strengthening hip abductors and hip flexors can reduce patellofemoral pain and ITB syndrome
- A balance between hip abduction and adduction strength can reduce lower limb injury risk
- Hamstring injuries can be prevented through eccentric strength and balance work
What do we recommend?
- Aim: strength train 2-3 times each week.
- Include a combination of heavy and moderate loading, explosive strength work and plyometrics.
- Plan needs to suit your individual needs and goals.
- In addition to lower limb exercises, need to target upper limb and core muscles that aid in ideal running posture.
Ask us for more information!
Source and further reading: https://doi.org/10.3390/sports10070098