Muscle Heat Stress - grows new mitochondria

This is an interesting study.  It is a bit of a cliche, but everyone talks about the mitochondria being the powerhouse of the cell.  They are where ATP, the energy currency of the cell is produced.  The more mitochondria you have the more fuel you will be able to generate in your muscles. (OK I am over simplifying)


Studies into interval training have found that high intensity training can induce mitochondrial biogenesis - i.e. grow new ones.

This new study indicates that the heat generated by exercise in muscles could be responsible for generating new mitochondria.  


Mild heat stress induces mitochondrial biogenesis in C2C12 myotubes

During endurance exercise, most (≈75%) of the energy derived from the oxidation of metabolic fuels and ATP hydrolysis of muscle contraction is liberated as heat, the accumulation of which leads to an increase in body temperature. For example, the temperature of exercising muscles can rise to 40°C. Although severe heat injury can be deleterious, several beneficial effects of mild heat stress (HS), such as the improvement of insulin sensitivity in patients with type 2 diabetes, have been reported. However, among all cellular events induced by mild HS from physical activities, the direct effects and mechanisms of mild HS on mitochondrial biogenesis in skeletal muscle are least characterized. AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) are key energy-sensing molecules regulating mitochondrial biogenesis. In C2C12 myotubes, we found that 1 h mild HS at 40°C upregulated both AMPK activity and SIRT1 expression, as well as increased the expression of several mitochondrial biogenesis regulatory genes including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and transcription factors involved in mitochondrial biogenesis. In particular, PGC-1α expression was found to be transcriptionally regulated by mild HS. Additionally, after repeated mild HS for 5 days, protein levels of PGC-1α and several mitochondrial oxidative phosphorylation subunits were also upregulated. Repeated mild HS also significantly increased mitochondrial DNA copy number. In conclusion, these data show that mild HS is sufficient to induce mitochondrial biogenesis in C2C12 myotubes. Temperature-induced mitochondrial biogenesis correlates with activation of the AMPK-SIRT1-PGC-1α pathway. Therefore, it is possible that muscle heat production during exercise plays a role in mitochondrial biogenesis.

Hillfit Manifesto

I've added a new page to the Hillfit Website - the Hillfit Manifesto.  The aim is to explain what it is all about, to summarise the drive behind the book.

Check it out and let me know what you think

Bad social experiences promote inflammation

This is fascinating - the impact of stress from competitors and general social interactions can promote inflammation.


Negative and competitive social interactions are related to heightened proinflammatory cytokine activity

These findings suggest that daily social interactions that are negative and competitive are associated prospectively with heightened proinflammatory cytokine activity.

It is all about environment.....but that is not just diet,  social interactions, other stresses are important too.  Getting your stress under control - work, relationships etc - is as vital as diet.  You can get diet and exercise dialed in but if you are chronically stressed from other things then you will still suffer. 

I am like this at the moment from work and family pressures

There is a good commentary here.

Stability and Mobility for natural running

Excellent stuff from the Natural Running Centre

Lots of good stuff here on posture, gait, mobility and stability



thanks to Jim Hansen for pointing this out

You have a brain so you can move

This came via a very good post from Marc Keys. He talks about skill development.  As we have said before strength is one thing, skill development is another.  Get strong and then apply it to your chosen skill, something I talk about in Hillfit

Natural Messiah had a great discussion of this video a few months ago

Exercise is good for older brains

Continuing the theme of keeping older brains healthy....I've had stuff before on how exercise increases insulin sensitivity (which we saw was a good thing) and how resistance training benefits older people.  Now this study which sees better brain performance in the elderly following intense exercise.

Acute moderate exercise enhances compensatory brain activation in older adults.

Insulin Resistance and brain health

Watching my Dad's dementia, brain health is becoming a real interest.  Here is a study which shows that reduced insulin sensitivity is linked to smaller brain size and deteriorated language skills in the elderly. 

"We found that in elderly whose insulin sensitivity was still high, the brains were larger, and they had more grey matter in regions that are important for language skills, compared with those who had diminished insulin sensitivity. We also observed that higher insulin sensitivity was associated with better scores on the language test. Our findings offer a possible explanation for why methods that improve insulin sensitivity, such as exercise, are promising strategies for counteracting cognitive aging late in life," says Christian Benedict.

Of course insulin resistance is complex - not just about eating too many carbs - and Stephan's series is a great outline of the issues.  Again, environment, genetics, gut flora are all kicking around but a real food diet, rest, exercise and reducing stress all help keep you sensitive to insulin.