Training load (or loading) is arguably the most important variable to consider when looking at the underlying causes of injury. The term ‘load’ in simple terms describes how hard your body is working during activity. While this is very important in athletes, it certainly also applies to everyday people. The total loading your body is under can be influenced by many different variables, including:
- Duration/distance – the total time (or distance) accumulated as part of your training or activity. This can be important in one single session of activity, or the total amount over a long period of time can also be important.
- Intensity – This relates to how hard you are working at one specific point in time. This could also be described as speed (if you are running, cycling, swimming, etc). The faster you are running during a session, the higher the intensity.
- Frequency – how often you are performing that particular activity. OR how often you are performing all your training activities. (This obviously relates to recovery as well.)
- Nature of activity – This is certainly relevant if you have changed the type of activity or training. For example if you normally run on grass, then you change to running on sand, or running up stairs. This change in the nature of your activity will change the load that your body is used to. This may also include a change in equipment used.
Changes to one or all of these variable will influence the total training load that your body is under.
Now your body is a fantastic machine, highly capable of adapting very well to the demands placed on it. However this adaptation takes time. When the loading demands placed on your body are greater than your tissues are able to adapt to (or greater than they are used to ) then your potential for pain and injury increase.
While this obviously applies to athletes, these principles definitely apply to regular people as well. In fact often even more so. Every day in the clinic we would see someone who comes in with a sore back/arm/leg/etc. after doing something that they haven’t done for a long time. It could be an office worker who had to pull down their pergola on the weekend (meaning much more gripping and lifting that they have done in months). Quite often it’s someone who’s decided to take up running, or crossfit, etc who went too hard too quickly (rapidly increasing their training load) and ending up getting injured.
Usually, when people come in to see us with load (or overload) related problems, they fall into one of two categories.
- They are training regularly but have changed something in their training load (duration/distance, intensity, frequency, nature)
- They have started a new activity (or had to perform an activity that they don’t do regularly)
When a patient attends the clinic complaining of pain (particularly with no obvious cause, like a sprained ankle) we dig deeper to try and identify the underlying cause of this issue. We want to know about your usually training, activity. We want to know if anything has changed – have you increased your ‘Ks’ on the bike? Are you running at a faster pace? Have you added a boxing session to your 8 other training sessions per week? Did you just get a new cricket bat that’s heavier than what you’re used to? Did you take a day off your cushy office job to dig soakwells all day?
Understanding exactly what you do, how you do it , how often and how hard allows us to pinpoint where things may have started to go wrong. It also allows us to modify some (or all) of these variables to (hopefully) allow you to keep training in some capacity.
Sometimes, patients will need a period of “de-loading” to allow the tissues to settle and fully adapt to the demands placed on them. This may mean complete rest for some people, this may mean modified activity for others. This may also mean avoiding certain parts of your normal activity. By understanding exactly what’s going on with your body, we can manipulate these loading variables to allow you to continue training in some capacity while still recovering from injury. OR we can actually encourage better recovery through appropriate loading.
Your body adapts to the loads it is placed under. If it is not placed under any load, it will lose the ability to withstand load. This is why astronauts lose muscle mass and bone density in space. Zero gravity means minimal load on the body. As your muscles don’t need to resist gravity to move you around, they become weaker over time. As your bones are not under much stress, they lose density because there is no need to maintain higher density.
You may have heard that weight bearing exercise, or weights training, is good for people with osteoporosis. This is true – osteoporosis is a loss of bone density (meaning more brittle bones that could be higher risk of fracture). Increased loading via weight bearing exercise help the body to adapt and stimulates greater bone strength. By manipulating loading we can actually improve people’s problems.
Another problem that can be treated with loading is chronic tendinopathies (think Achilles tendon issues in runners, or patella tendon issues in volleyballers). Tendinopathy is complex, but in simple terms it is usually a failed adaptation (healing) within the tendon following excessive loading. Now to stimulate adaptation and recovery we actually need to load the tendon the right way and the right amount. This is where specific control of loading variables actually helps to “heal” the problem, while excessive loading actually makes the problem worse. You should note that rest (ie no loading) actually doesn’t help long term recovery, and actually leads to weakening of the tendon over time.
“Overload” can occur for a number of different reasons. Sudden increases or changes in activity can lead to pain and injury as your body is just not accustomed to that amount of total load. The best advice is to increase gradually so your body has a chance to adapt to the increased demands. How gradually is difficult to determine, and I believe this really can only be determined individually. There is a rule of thumb in running circles that you should only increase by 10% at a time. While this is common sense to not increase too quickly, research has shown that 10% doesn’t exactly change the injury risk. However the key message here is Start slowly and build up gradually.
At South Perth Physiotherapy we get to know you and your activity levels deeply, so we can truly understand everything that may be contributing to your issues, and carefully modify these loading variable to allow you to continue to participate as much as possible while still appropriately treating your injury.
Julian is a Director and Senior Physiotherapist at South Perth Physiotherapy. He has spent over a decade working exclusively in private physiotherapy practice, and estimates he would have performed over 35,000 individual treatments in that time. He has worked with everyone from Paralympians, elite athletes, WAFL Footballers, the Defence Forces and weekend warriors; to thousands of everyday people with all manner of issues. He is passionate about injury prevention and has a special interest in the treatment of headaches, shoulder issues, hypermobility management and exercise rehabilitation for the prevention and treatment of injuries.
Khan & Scott, (2009). Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair. British Journal of Sports Medicine, 43(4), 247-252.
Glasgow, et al. (2015). Optimal loading: key variables and mechanisms. British Journal of Sports Medicine, 49(5), 278-279.
Buist, et al. (2008). No effect of a graded training program on the number of running-related injuries in novice runners: a randomized controlled trial.American Journal of Sports Medicine, 36(1), 33-39.