March 1, 2012, by Simon Butt
Exercise assumptions challenged by science
In the office we have been talking about Tuesday night’s BBC Two programme Horizon: The Truth About Exercise.
“Did you know you can get away with doing just three minutes of exercise a week?”
(Cue frowns and disbelief from those who spend hours running or sweating in the gym and glints of hope from the rest who currently do no exercise…)
But this is not three minutes of any old exercise – it’s HIIT: High-Intensity Interval Training; just one of the ways of staying fit and healthy based on more accurate scientific insight investigated by Horizon presenter, health journalist Michael Mosley.
Intense bursts in Nottingham’s labs
Mosley became a human guinea pig throughout the making of the programme (and beyond) to test some of the latest science underpinning what we understand about exercise and fitness. Much of his programme was filmed in the labs of Prof Paul Greenhaff here at The University of Nottingham.
Among the many research programmes metabolic physiology expert Paul is engaged in, he collaborates with Prof James Timmons from the University of Birmingham, who is Principal Coordinator of the EU-funded Metapredict project.
Jamie completed his PhD in muscle physiology and metabolism with Paul Greenhaff at The University of Nottingham in May 1996 and, after working in industry and academia, is now Chair of Ageing Biology at Birmingham.
Two key sequences in this week’s programme were filmed in Paul’s labs because Nottingham is a main UK centre executing HIIT training in overweight, middle-aged people on which genomic based predictors will be developed.
Metapredict’s collaborators are seeking to “identify molecular biomarkers for response to exercise training, so that individualised lifestyle strategies can be developed to fight or prevent metabolic diseases such as obesity, diabetes and cardiovascular disease”.
The project combines systems biology, physiology, metabolomics, and DNA and RNA analysis to develop personalised medicine strategies. It will establish diagnostics that can predict the long term consequences of insulin resistance on muscle ageing.
One of the revelations for host Michael Mosley in the Horizon episode is that the HIT exercise regime over four weeks improved his insulin sensitivity by a remarkable 24%. However, the gene tests he had taken accurately predicted that his aerobic fitness would not improve at all – he is one of 20% of the population pre-determined to be ‘non-responders’ for cardiovascular fitness. (At the other end of the spectrum, around 15% of people are ‘super-responders’.)
Metapredict includes participants from the Universities of Birmingham and Nottingham, the Karolinska Institute in Sweden, and other top institutions worldwide. Since the Horizon programme was publicised, the team has “inundated” with people wanting to volunteer for MetaPredict!
Effects in ageing
Personalised exercise and health protection strategies are central to Jamie’s work and to that of Paul Greenhaff, who is also Deputy Director of the new MRC-ARUK Centre for Musculoskeletal Ageing run jointly by the Universities of Birmingham and Nottingham. Its Director is Birmingham’s Professor Janet Lord. These two universities are currently celebrating the first anniversary of their landmark institutional collaboration.
The team will spend the next five years investigating why musculoskeletal tissue metabolism, function and mass decline with age and will explore the risk factors and biological events involved in these processes. They also want to find out how diet and exercise interventions may offset this deterioration.
Other research with colleagues Prof Michael Rennie, Dr Philip Atherton, Dr Ken Smith and others at Nottingham, discovered several years ago that muscle protein metabolism during feeding is blunted with age but that weight training may “rejuvenate” muscle blood flow and help retain muscle for older people. This BBSRC-funded research is currently being extended to investigate the added burden of obesity on muscle mass regulation and insulin resistance in ageing.
Paul has also worked on some of the side-effects of the statins most commonly prescribed to lower cholesterol in older people. These have been found to cause loss of muscle mass and premature fatigue, especially in older people.
The future of exercise?
So this week’s programme – which also advocated exercise before eating to help break down fat and not sitting still for more than an hour (“Chairs kill!”) – should make us think, and link science more carefully to the decisions we make about what we eat, whether/when we exercise, and the exercise we do to stay fit and healthy.
Paul Greenhaff and his Nottingham colleagues leads the advance of sports nutrition in other ways based on new scientific evidence that could help the ‘super-responders’ among us to achieve dramatic benefits.
Last year he and his team discovered that a naturally occurring nutrient, L-carnitine, when combined in a particular way with carbohydrate and exercise over six months, delivers significant performance improvements. Now they have created a supplement for elite athletes which is already being used in training for top sports events.
Better understanding of how nutrients, exercise and metabolism work together to help our bodies stay healthier and work more effectively promises a fitter future.