This is part 1 of this month’s series: Load Management in Sport.
Looking at the yearly schedule of any elite sports athlete or team, there really aren’t many free ‘gaps’.
Sometimes there doesn’t even seem to be a clear ‘off-season’. The end of one competition is quickly followed by international tournaments, or the start of the next pre-season.
Loading in sport, then, appears to be a concept that is constantly monitored, or at least should be, when considering injury risk and recovery.
What exactly is a loading injury?
A loading injury occurs when training load has exceeded the bodies ability to adapt.
There are several aspects of the athletes ‘make-up’ that can be considered when looking at loading capacity (and ability to adapt).
- Physical conditioning of various tissues (muscles, tendons, bones).
- Cognitive and affective factors, such as mental toughness, resilience, as well as concepts such as fear of injury, and mindfulness.
More will be written in the coming weeks on these cognitive and affective aspects of tissue healing and recovery.
What is the ideal training load for optimal sports performance and reduced injury risk?
It’s a good question.
The answer will certainly depend of what sport is being considered.
As a general concept, ideal tissue loading will be situated in between the following:
- Minimum load required to improve performance.
- Maximum load required before tissue injury/overload.
So at the ends of the spectrum, no loading will lead to poorer performance, whereas excessive loading will lead to an increased risk of injury.
With every sport, there is a need to understand the specific loading requirements of not only that sport, but the athlete’s individual role.
As physiotherapists, it is important to have a good understanding of task-specific tissue demands, in particular those that are susceptible to overloading.
An example, described recently by Specialist Sports Physiotherapist, JP Caneiro (as awarded by the Australian College of Physiotherapists in 2013), included an overview of bony stress injuries found in elite rowing¹.
JP shared his experience in identifying early signs of bony stress in susceptible areas such as ribs, and that closely monitoring the athlete’s response to load over the course of a season is important.
Different roles within a rowing squad will also demonstrate different individual loading patterns and subsequent responses to load. This highlights the importance of knowing your athletes well, and knowing how their body is being stressed differently to their teammates.
There has been extensive research into loading and injury rates in elite Australian cricketers. This is largely due to the historical prevalence of bone stress injuries and soft tissue strains in fast bowlers.
When measuring total number of balls bowled per week (external workload), and multiplying the session rating of perceived exertion by session duration (internal workload), they found that large increases in acute workload were associated with increased injury risk².
One study reported that bowlers who bowled more than 50 overs in a match had an injury incidence in the next 21 days of 3.37 injuries per 1000 overs bowled, significantly higher than bowlers who bowled less than 50 overs³.
Therefore, in some sports it is thought that athletes may experience a delay in the onset of injury (3-4 weeks), based on acute loading factors³. This may be due to inadequate time for tissues to unload, repair, and adapt to this increased load³.
What does it mean when tissues adapt to a new load?
Many examples in the literature describe the nature of stress adaptation in musculoskeletal tissues, such as bone, muscle, and tendon.
If stress/load occurs under physiologically acceptable conditions, a functional adaptation will occur within these tissues at a cellular level⁴. This can result in an actual alteration in tissue structure⁴.
In terms of bone stress, when the increased load ceases, cells are able to move through a natural process of old bone resorption (osteoclasts), and new bone remodelling/mineralisation (osteoblasts)⁴.
This would mean that once adaptation has completed, the tissue is structurally more capable of handling the next loading cycle.
So how do we measure what is the ideal load?
There are various validated measurements used to examine an athletes response to current tissue loading. These qualitative and quantitative measure will be discussed in the next article of this month’s Load Management in Sport.
If you have any sports-specific clinical experience in managing load with athletes, please feel free to share below in the comments section. There are many clinicians that will benefit from any insights that you can share.
Creative Commons image courtesy of See-ming Lee.
- Lecture: Load Management in Sport. Presented by JP Caneiro, APA Nedlands, 20 November 2013.
- Hulin B, Gabbett T et al 2014, ‘Spikes in acute workload are associated with increased injury risk in elite cricket fast bowlers’, British Journal of Sports Medicine, vol. 48, no. 8, pp. 708-712. [PMID: 23962877]
- Orchard J, James T et al 2009, ‘Fast bowlers in cricket demonstrate up to 3- to 4-week delay between high workloads and increased risk of injury’, American Journal of Sports Medicine, vol. 37, no. 6, pp. 1186-1192. [PMID: 19346405]
- Petrtyl M and Danesova J 1999, ‘Bone remodelling and bone adaptation’, Acta of Bioengineering and Biomechanics, vol. 1, no. 1, pp. 107-116. [Link]