TRAINING
Stress has negative connotations, but is it always a bad thing? And how does it affect runners’ health and performance?
THE WORLD HEALTH ORGANIZATION defines stress as any type of change that causes physical, emotional or psychological strain. The Hungarian-Canadian endocrinologist Hans Selye developed the concept of a ‘general adaptation syndrome’, where organisms respond to stress in a similar way regardless of what causes it.
Selye defined three response stages. Initially, the ‘alarm’ stage is characterised by a release of hormones (such as cortisol) and other processes that create our flight-or-fight response. The second stage of ‘resistance’ is where organisms adapt and develop resistance to the stress. And finally, ‘exhaustion’, where, if a stress is applied for long enough, organisms can no longer respond and start to break down and lose resistance. This concept is useful when applied to running because it recognises that a managed dose of acute stress can be beneficial, but a heavy or sustained dose of chronic stress can become negative. As runners, we must focus on our dosage.
• The stress balance
Our fitness relies on a balance between the stimulus from stress and the adaptation from recovery. When our managed doses of acute stress balance with recovery, our body goes through a process known as supercompensation, adapting and building resistance. But when stress outweighs our ability to recover – especially for prolonged periods – our body goes through a catabolic process of breaking down. If we get to this point, we risk injury and poor performance, as well as losing the ability to build further fitness. We’re also likely to see changes such as a loss of enjoyment, poor sleep and even wider physical changes that affect long-term health.
• Different types of stress
To get this balance right, we need to consider stress in the broadest sense.
Stress from training: This is the physical stress we create through our training decisions. Through a balance of the frequency, intensity and volume, and how it builds over time, we can create a stress stimulus to help us build fitness. This needs to be considered at a macro level – the overall training load from our training plan over a long period; a meso level – the impact of changes in stress through a training cycle, for example when building up to a specific race; and a micro level – the impact of training stress from our training week and individual sessions. These can be considered controllable variables. However, just because they’re controllable, doesn’t mean we always get these decisions right.
Stress from life: Selye’s concept of ‘general adaptation syndrome’ means we also have to look beyond the physical stress
