Part 2: Periodization training as it relates to injury prevention.
Structured training through periodization gives runners a competitive edge, but it also aids in injury prevention. Part 1 of this three part series discussed performance implications for periodization training- how structuring a year around training blocks can help an athlete achieve greater levels of fitness. This next section will outline how periodization training can decrease an athlete’s likelihood of getting injured as well as preview methods of progressing back from an injury.
To develop resilience as a runner an individual needs to train at an overall load that is less than their capacity. In rehabilitation, tissue capacity refers to the maximum load a tissue can bear without losing its structure. Tissue load refers to the amount of force the athlete is applying to the tissue on any given workout, week, or training block. Running-related overuse injuries, including tendinopathies and bone stress injuries commonly develop when the cumulative tissue load exceeds that of the tissue’s capacity over time. In achilles tendinopathy, the cells that form the achilles tendon are structurally overloaded to the point where the cells deform and the achilles loses its ability to generate a spring force. In a tibial stress fracture, bone formation falls behind bone breakdown, leading to an inherent weakness in the bone. In healthy individuals, tissues do not spontaneously break down. There needs to be an acute load applied to the tissue that exceeds the tissue capacity. Through blunt trauma, like that of an ankle sprain, the load applied to the lateral ankle ligaments quickly exceeds that of the ligaments’ capacity and the runner rolls their ankle. While this is spontaneous and unpredictable, there is a clear cause and effect. What may be less apparent is when load exceeds capacity from overuse- this occurs over the course of days, weeks, or months.
Part 1 of this series discussed how a runner improves fitness over time through a process called supercompensation. The runner starts training at a relatively low level of fitness and over the course of weeks to months applies a training stimulus in the form of a training block. To learn more about these concepts please reference Part 1: Periodization as It Relates to Performance.
While appropriately structured training blocks can lead to supercompensation over time, inappropriately structured workouts and training blocks can lead to fatigue, burnout, and injuries. If workouts are too hard or too closely spaced without an appropriate recovery window, tissue capacity enters a red-zone where the athlete is at a higher risk of injury.
Like cardiovascular fitness, tissue capacity also responds to training load. Runners like to run and often disregard any other form of loading. However, running is a poor method to increase tissue capacity and can result in tissue breakdown. Contrary to running, strength training is an excellent and safe way to load muscles, bones, tendons, and ligaments.
A core component of strength training is progressive resistance training. Progressive resistance training, like supercompensation, focuses on incrementally loading tissue overtime. This allows an individual to get stronger overtime. When we think of progressive resistance training we commonly think of muscle strength. However, this concept is not solely limited to muscle cells and can also be applied to tendons, ligaments, and bone. This explains how a runner can develop resiliency over time. By appropriately structuring training over the course of months to years, an athlete is increasing their capacity to load for longer durations with higher intensities.
In Part 1, we examined how Violet and Dash (two fictional runners of incredible ability) developed fitness over time. Violet was more structured with her training blocks in her build to the Boston Marathon. She took appropriate time off during the year and structured her workouts strategically. Dash on the other hand was less structured in his training- he ran and raced spontaneously and kept his mileage relatively high throughout the year. In Part 2 we will examine how both of these strategies affect tissue capacity.
Violet is a less experienced runner than Dash but she started her training for Boston about eight months out. She started with a very low base and built over the course of months. At the start of her training her likelihood for injury was relatively high because her base was less established and her tissue capacity was relatively low. Therefore, her preparatory period was long and had a slow build to it. During this time she also incorporated strength training and cross training in order to help develop a larger tissue capacity and resiliency. Thus, her fitness over time graph looked like this:
While Violet is relatively close to her injury zone earlier on in training, as her fitness increases her tissue capacity also increases. This gives her more margin for error later in the season when she is taking on larger training blocks with more training load.
Injuries commonly develop at the end of a training block when the athlete is most fatigued. Blocking several hard weeks of training can be an effective way to develop cardiovascular fitness; however, if at the end of the training block the tissue load has exceeded that of the tissue capacity the athlete is at a higher risk of injury.
During the Winter Dash ran a 70 mile week with two interval days. After a longer run on Sunday he starts to feel tension in his achilles. The next week he decides to not do any workouts to “keep it easy” but he maintains his weekly miles at 65. The week after his achilles gets hot and painful and he is forced to take the week off. During his week off he feels better because he is not running; however, his pain comes back again when he tries to jump back into 65mi weeks. He now has to take another week off. At this point Dash has lost time in his training and is now considered injured.
Moreover, his tissue capacity has been significantly detrained by taking two full weeks off running. It will take a substantial amount of time to progressively rebuild his lost tissue capacity. During this time he has to partake in several weeks of lower training with more cross-training and strength training to establish both his weekly volume and tissue capacity. Because Dash is an experienced runner with a base that has been developed over the course of years he is able to return to his normal volume. However, because Dash does not periodize his training he is always going to be at an increased risk for injury. While his tissue capacity for load is relatively high, he never takes any down weeks and this commonly causes him to develop achilles tendinosis which affects his training in the long term.
Importantly, cardiovascular fitness develops faster than tissue capacity. For the inexperienced runner this can be problematic early in their career as they quickly become better runners from an aerobic perspective but easily exceed their tissue capacity and develop injuries.
This is best illustrated by Dash and Violet’s younger brother Jack Jack (JJ). JJ becomes inspired by Dash and Violet’s training for the Boston Marathon and decides to sign up for a half marathon two months away. Unlike his brother Dash, JJ has not been running for years and has close to no resiliency. Unlike his sister Violet, JJ did not start training 8 months out of his event; thus, he has not provided himself time to develop a base. Unsurprisingly, after going out on a couple runs with his brother (who often runs too hard for too long) JJ develops patellar tendinitis as he runs himself into the injury zone.
At this point JJ’s event is only several weeks away. He insists on following through with his race. While working with a physical therapist he is able to complete the race, he is now significantly in the injury zone and has to take even more time off in order to redevelop tissue capacity.
Structured training through periodization gives runners a competitive edge, but it also aids in injury prevention In order to become more resilient, runners must increase their tissue capacities over months to years. We tend to conceptualize injury management and performance separately when talking about training. However, the reality is, runners who refrain from getting injured can spend more time working on developing performance. The intent of Part 2 in this series was to illustrate how runners of various abilities commonly develop overuse injuries. Part 3 will focus on common methods physical therapists and coaches use to progress runners out of the injury zone and reestablish a healthy tissue capacity.