Busy....

I'm busy with work at the moment.  I'll be back posting more regulalrly when things quieten down a bit.

Hair, sun and heat

A strange study!

Head Hair Reduces Sweat Rate During Exercise Under the Sun

Martial Arts is bad for your muscles?

Interesting.  The physiological and psychological stress of sparring creates a hormonal response which is catabolic.  Testosterone goes done....cortisol goes up.

So by all means train in martial arts, but be careful of the level of stress - physical and psychological - that you are using.

Hormonal response to Taekwondo fighting simulation in elite adolescent athletes

Exercise training efficiency depends on the training load, as well as on the athlete’s ability to tolerate it. The aim of the present study was to evaluate the effect of fighting simulation (3 fights, 6 min each, 30 min rest between fights) on anabolic (IGF-I, LH, FSH, estradiol, and testosterone) and catabolic hormones (cortisol) in elite, male (n = 10) and female (n = 10) adolescent (12–17 years) Taekwondo fighters. Blood samples were collected before the first and immediately after the third fight. The fighting simulation practice led to significant (p < 0.05) decreases in IGF-I (males −27.1 ± 25.6, females −22.4 ± 36.3 ng/ml), LH (males −0.7 ± 1.2, females −2.3 ± 3.3 U/L), and FSH (males −0.9 ± 0.5, females −1.5 ± 1.1 U/L), and to a significant increase (p < 0.05) in cortisol (males 141.9 ± 30.1, females 64.1 ± 30.6 mcg/dL) in both genders. Fighting simulation decreases in testosterone (males −1.9 ± 1.6, females −0.02 ± 0.06 ng/mL), and free androgen index (males −20.1 ± 21.5, females −0.3 ± 0.5) were significant (p < 0.05) only in male fighters. Exercise had no significant effect on estradiol, sex-hormone-binding globulins or thyroid function tests. Our data demonstrate that the physiologic and psychologic strain of a Taekwondo fighting simulation day led to a catabolic-type circulating hormonal response.

Heat grows muscles!?

This is weird! Comments please?

Responses of muscle mass, strength and gene transcripts to long-term heat stress in healthy human subjects

The present study was performed to investigate the effects of long-term heat stress on mass, strength and gene expression profile of human skeletal muscles without exercise training. Eight healthy men were subjected to 10-week application of heat stress, which was performed for the quadriceps muscles for 8 h/day and 4 days/week by using a heat- and steam-generating sheet. Maximum isometric force during knee extension of the heated leg significantly increased after heat stress (~5.8%, P < 0.05). Mean cross-sectional areas (CSAs) of vastus lateralis (VL, ~2.7%) and rectus femoris (~6.1%) muscles, as well as fiber CSA (8.3%) in VL, in the heated leg were also significantly increased (P < 0.05). Statistical analysis of microarrays (SAM) revealed that 10 weeks of heat stress increased the transcript level of 925 genes and decreased that of 1,300 genes, and gene function clustering analysis (Database for Annotation, Visualization and Integrated Discovery: DAVID) showed that these regulated transcripts stemmed from diverse functional categories. Transcript level of ubiquinol-cytochrome c reductase binding protein (UQCRB) was significantly increased by 10 weeks of heat stress (~3.0 folds). UQCRB is classified as one of the oxidative phosphorylation-associated genes, suggesting that heat stress can stimulate ATP synthesis.

These results suggested that long-term application of heat stress could be effective in increasing the muscle strength associated with hypertrophy without exercise training.

Astronaut conditioning research

I saw this in the New Scientist - How to survive the long haul in space - it is about how to tackle some of the health problems associated with being in space.

It turns out that maintaining the strength of muscle and bone is really important.....and is also a real challenge when weights are weightless.

In terms of High Intensity Interval Training (HIIT) there are a few interesting ideas being tried out:

Short bursts of high-intensity resistance training, at around 70 per cent of the muscles' maximum capacity for 15 minutes, twice a day, should help, says Fitts. A range of studies in animals and volunteers confined to bed rest suggest this will protect muscles better than long periods of low-intensity aerobic exercise. It may also guard against bone loss. Dan Bikle of the University of California, San Francisco, who has studied bone loss in rats whose hindquarters are suspended off the ground, recommends intense weight-bearing exercise for 1 second in 10, for a few minutes each day

What also caught my eye though was the idea of using resistance bands. They have been using what NASA call an Interim Resistive Exercise Device (IRED):

There has been a bit published on the studies which they have done with the device. Interestingly while it helped preserve muscle it did nothing for the bone density.

Scientists found that the only way they could reverse this process was by using exercises that deformed the bone cells (think of them squishing, like a tennis ball you’re standing on). This, they found, slowed bone mineral reabsorption (a natural process in the body that weakens bones) and increased bone density. They thought the iRED would accomplish this. But it didn’t work.
“The elastic bands simply didn’t provide enough resistance,” says Garcia. “And the resistance they did provide wasn’t consistent enough to affect the bone mass of the astronauts.”

That is from this interesting commentary which has a few key principles of the sort we might be familiar with here:

Rule 1: Use heavy weights (at least 80 percent of your max).
“In order to sufficiently work muscle and bone fiber to the point where the aging process is slowed,” says Spiering, “people can’t just run and play sports.” In space, the NASA astronauts experienced accelerated atrophy — even if they ran on treadmills. Heavy lifting — rather than static loading, as during a jog — was the only way, NASA scientists found, to deform the bone cells enough to grow cortical bone. To achieve this effect on Earth, Spiering found that resistance training — exercises such as squats, bench presses, and dead lifts — at 80 to 85 percent of the maximum amount you can lift is the optimum way to stop bone and muscle deterioration.

Rule 2: Slow down. Lifting weights isn’t nearly as critical as how you lower them.
The iRED revealed that the fluctuating resistance due to its elastic webbing limited eccentric forces — the resistance generated by lowering a weight — by 60 percent. Although iRED users were able to gain some muscle strength from the machine, their bone density decreased rapidly. Schneider assumed that the machine’s inability to generate eccentric force was the culprit. So in 2003 she put a group of men on a steady diet of exercises with free weights, which increase eccentric force when lowered slowly. (This theory had been out there before. In the early 2000s, many fitness buffs began clinging to an exercise program called Super Slow, which promised to increase metabolism and lower bad cholesterol. It seemed to work — though people weren’t sure why — and soon after many people replaced it with more functional training like CrossFit.) After 16 weeks, she tested the men’s bone mineral density and found that it had improved dramatically from their pre-program levels.

Rule 3: Drop the number of reps (keep the intensity high).
Earlier this year Scott Trappe, the director of the Human Performance Lab at Ball State University, in Muncie, Indiana, used NASA’s data from nine astronauts aboard the ISS to conduct and publish a study about weightlessness and exercise in the Journal of Applied Physiology. Using MRIs and biopsies to measure muscle fibers, he concluded that intense movements, like sprinting, jumping, and throwing (see the exercises at right), along with lifting heavy weights, resulted in better muscle size, a key element to protecting bones and thus keeping them from aging too quickly. The discovery wasn’t exactly surprising, but Trappe’s study did bust one misconception about the amount people exercise. “Most people think that more is better,” he says. “But our study showed that exercise should be done much less frequently than conventional wisdom suggests — but with much greater intensity.” Says Garcia: “The most recent space flight research indicates that doing six to eight reps — not the typical 10 — best maintains muscle function and strength.” In a recent study, Trappe found that elderly men who had been training three days a week, at 80 percent of their maximum loads, were able to maintain their muscle mass with just one high-intensity workout a week.

I don't know where I am going with this, but it is an interesting bunch of stuff to read. Train hard, less frequently, with slow negatives using heavy weights. Arthur Jones, John Little and Doug McGuff would be proud of NASA!

I'm not sure what it says about resistance bands though, if anything.

Last one

Superb stuff from Damien Walters

100 rep challenge

Check out the new website for the 100 rep challenge. This is an initiative from my pal Rannoch - interviewed here.

The One Hundred Rep Challenge is……..

A simple practice designed to establish an re-enforce positive, enduring habits
Suitable for everyone, young & old, active & sedentary, everyone can benefit by using 100 reps to work on the areas of their mental & physical wellbeing that require attention. We approach everything as scalable” – rather than one size fits all, the 100 Rep Challenge helps participants find the best route for themselves

The Challenge is a personal one, about accountability and the value of consistent effort. It can work as an individual or group effort but the focus remains a personal one. The Challenge can be used by teachers, coaches, trainers, athletes, families and groups of any kind who require a starting point for a simple daily practice.

Almost any physical activity can be adapted to the Challenge. 100 is simply a number, a starting point, a catalyst. The drills themselves can be about anything that promotes a sense of ownership regarding our health and wellbeing. Mindfulness breathing, stretching and mobility, strength training, rehabilitation –- all of these modalities have their place.

Some time ago it became obvious to some of us that we were sending people on a journey without a map. They knew where they wanted to go, …they just didn’t have a compass. Anyone can learn the basics of getting fit, eating sensibly, taking better care of themselves but without a regular daily practice to re-enforce these habits it is HARD. Why is it bad habits are so difficult to break when good habits are so easy to give up?!

We all need simple rituals, a practice in our lives, that amidst the chaos allows us a little time to breath, move, take charge, focus and relax. The studies on the benefits of regular physical activity are numerous. Mentally, physically, emotionally, we can all benefit from a little movement and perhaps a little stillness. And once a regular practice takes hold the bigger challenges we face suddenly don’t seem quite so intimidating.

Join them on Facebook too.

In some ways it reminds me of Joel's site.

Exercise and brain function

This was interesting. I've pointed to similar things before - e.g. the post on Spark and the follow up one.

moderate exercise – in this case walking at one's own pace for 40 minutes three times a week – can enhance the connectivity of important brain circuits, combat declines in brain function associated with aging and increase performance on cognitive tasks.

The higher the connectivity, the better the performance on cognitive tasks, especially the ones we call executive control tasks – things like planning, scheduling, dealing with ambiguity, working memory and multitasking," Kramer said. These are the very skills that tend to decline with aging, he said.

There is more in the report here and the full study (pdf) is available from the link below:

Plasticity of brain networks in a randomized intervention trial of exercise training in older adults

Some more low carb research

Effects of a Low-intensity Intervention That Prescribed a Low-carbohydrate vs. a Low-fat Diet in Obese, Diabetic Participants


Low-carbohydrate diets have been associated with significant reductions in weight and HbA1c in obese, diabetic participants who received high-intensity lifestyle modification for 6 or 12 months. This investigation sought to determine whether comparable results to those of short-term, intensive interventions could be achieved over a 24-month study period using a low-intensity intervention that approximates what is feasible in outpatient practice. A total of 144 obese, diabetic participants were randomly assigned to a low-carbohydrate diet (<30 g/day) or to a low fat diet (≤30% of calories from fat with a deficit of 500 kcal/day). Participants were provided weekly group nutrition education sessions for the first month, and monthly sessions thereafter through the end of 24 months. Weight, HbA1c, glucose, and lipids were measured at baseline and 6, 12, and 24 months. Of the 144 enrolled participants, 68 returned for the month 24 assessment visit. Weights were retrieved from electronic medical records for an additional 57 participants (total, 125 participants) at month 24. All participants with a baseline measurement and at least one of the three other measurements were included in the mixed-model analyses (n = 138). The low-intensity intervention resulted in modest weight loss in both groups at month 24. At this time, participants in the low-carbohydrate group lost 1.5 kg, compared to 0.2 kg in the low-fat group (P = 0.147). Lipids, glycemic indexes, and dietary intake did not differ between groups at month 24 (or at months 6 or 12) (ClinicalTrials.gov number, NCT00108459).

This sounds like a real life Supersize Me

Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity


Full paper available