Latest News & Research: 7 August 2018

This week: The molecular switch for muscle growth • Heat treatments may boost ‘the powerhouse of the cell’ • New campaign urges Aussies to move it or lose it

The molecular switch for muscle growth

A new study has investigated why people respond differently to the same training stimulus and build muscle more easily than others.

Lead study author Sarah Lessard, PhD, identified the role that a protein molecule called c-Jun N-terminal kinase (JNK) can play: ‘It's like a switch [...] If the switch is on, you'll have muscle growth. If it's turned off, you have endurance adaptation in the muscle. We've identified an exercise-activated biological pathway that hasn't been studied at all’.

In rodent treadmill studies, Lessard’s team found that mice with the JNK gene doubled their muscle mass, whereas those without it showed no growth. However, the JNK-free mice did significantly increase their aerobic capacity as well as their endurance.

Tests on human subjects also backed up the relationship between JNK and muscle growth.

Source: Medical News Today


Heat treatments may boost ‘the powerhouse of the cell’

A new study has found that long-term heat therapy may increase mitochondrial function in the muscles – a discovery that could lead to new treatments for people with chronic illness or disease.

Often called the ‘powerhouse’ of the cell, for its ability to oxidise fuel sources to create energy, mitochondria are critical for health and the evolution of the human species. The more mitochondria we have, the lower our risk for developing many chronic diseases. The average individual may have literally billions of mitochondria in their skeletal muscles, and the trained individual even more. It has been estimated to comprise around 10 per cent of an individual’s body mass.

Identifying exercise as a barrier to creating new mitochondria in people with chronic illnesses, researchers from Brigham Young University in Utah studied 20 adult volunteers who had not participated in regular exercise in the three months prior to the study. The research team applied two hours of shortwave diathermy, a type of heat therapy designed to mimic the effects of muscle heating that occur during exercise, to the thigh muscles of one leg each day for six days.

Compared to the untreated ‘control’ thigh muscles, the heat-treated legs exhibited an increase in mitochondrial function of 28%.

‘Our data provide evidence to support further research into the mechanisms of heat-induced mitochondrial adaptations’ the researchers explained. People who are not able to exercise for long periods of time due to their health may benefit from heat treatments.

Source: American Physiological Society


New campaign urges Aussies to move it or lose it 

Sport Australia has launched a new campaign ‘Move It AUS’ to encourage Australians of all backgrounds, ages and abilities to become physically active and move more often.

The campaign calls on Australian adults to find at least 30 minutes of physical activity per day, and 60 minutes of activity per day for children.

Australia is the third most obese English speaking country in the world, with two thirds of adults and a quarter of children considered overweight or obese. One study predicts Australia faces $88 billion of extra health and social costs over the next 10 years if people don’t get moving.

AIS Chief Medical Officer Dr David Hughes said; ‘Just 30 minutes of physical activity per day reduces the risk of heart disease by 35 per cent, helps to keep you fit and flexible, and improves overall health and wellbeing.’

The campaign forms part of Sport Australia’s new vision, for Australia to become the world’s most active sporting nation. The Australian Government’s target is to reduce inactivity by 15% by 2030.

Source: Sport Australia