Mind The Strength Gap
The growing need to boost kids' strength capacities to enable them to participate successfully
An overlooked consequence of declining physical activity and outdoor play is that kids today are notably weaker than in previous generations. Physical performance measures requiring muscular strength have shown a steep downward trend over recent decades. Deficiencies in strength capacities are likewise a contributing factor in the declining levels of athleticism among children and teens. Kids who lack strength are also physically less robust, as muscular strength undergirds the body’s resilience to the stresses and strains associated with sport. Strength deficits are thus implicated in the musculoskeletal injuries that are increasingly common in youth sports.
The suggestion that kids engage in resistance training when their bodies are still growing and developing was originally met with some caution. The concern was understandable but happily the debate regarding the safety of youth resistance training is now effectively settled, thanks to the positive results of many years of research investigation. Based on this evidence the consensus among the relevant national and international bodies is that strength training under qualified supervision is safe, effective and highly beneficial for children and teens. Not only has the conversation moved on from debating the potential hazards of youth resistance training, what is even more notable is that the focus has now switched to the negative consequences if kids do not engage in strength training.
It should be said that the message regarding the safety, efficacy and indeed the growing necessity of strength training for young athletes has not necessarily trickled down to the those operating in the field (here in Canada, I continue to be surprised by the outdated beliefs that still persist in some corners). Certainly parents did not get the memo, so they can absolutely be forgiven for not knowing, given the lack of public messaging efforts to disseminate this information so that people can update their views on the topic. Here is my attempt to address that glaring omission!
The capacity to apply force is essential for athletic movement. Strength is required to overcome our own inertia in order to move. In turn, we depend on strength capacities to handle and direct our own momentum once we are in motion. We must apply force in the proper place in relation to our own centre of mass to halt our momentum or to change our direction of travel. Likewise during skilled movements such as throwing we must exert muscular force to first accelerate and then decelerate our own limbs.
The ability to move effectively requires a threshold level of force-generating capacity at each link in the chain. These minimum requirements vary according to the athletic activity in question. More dynamic movements demand greater levels of strength and naturally the minimum requirements change with age, as limbs grow longer and young bodies become heavier. As we have discussed before, this represents a particular challenge for girls as they hit their teens, as several major muscle groups fail to keep pace with the growth of limbs and gains in mass that accompany puberty in females.
A young person’s experience of participating in youth sport will vary dramatically according to whether or not they possess adequate levels of strength for the demands involved. As long as they meet the threshold level of physical capacity they will be able to participate. However, if they drop below that threshold they will find their ability to participate is compromised and they are liable to suffer more injuries. The best case scenario is for kids to not just meet the minimum requirements but to exceed them - in other words, to become strong - so that they have extra capacity in reserve. This will not only allow them to perform better but also increase their resilience and protect against the majority of youth sports injuries that are avoidable.
Lacking the physical capacities to meet the minimum strength requirements for the sport clearly poses a major barrier for participation. Returning to the example of young females, this helps explain the massive rates of drop out among girls after they reach adolescence. Aside from impairing their ability to participate successfully, a lack of strength capacity impairs function and dynamic stability, which makes kids susceptible to injury at any link in the kinetic chain that is affected. This predisposes kids to both acute injury (arising from a single injury event) and overuse injuries (otherwise known as ‘biomechanical overload injuries’) that result from cumulative wear and tear over time.
There is a further link between injuries sustained due to physical deficits and the decline in youth sports participation. An illustrative example is a study of junior track and field athletes revealing that injury is the most commonly cited reason for dropping out from participating in sport. Once again, female athletes are disproportionately affected by this, not simply because they are more likely to exhibit strength deficits following puberty but also because adolescent females suffer more lower limb injuries than their male counterparts.
The final point to emphasise with young performers is that they are only as strong as their weakest link. Athletes are very adept at finding workarounds and many fall into the habit of moving in a way that favours the area where they are strong, whilst avoiding taking load through weaker links, which only compounds the issue (i.e. strong links get stronger, whereas underused weak links get weaker). This is something that needs to be guarded against in the gym, especially with adolescent females who are a few years post puberty. A knowledgeable practitioner can accomplish this by selecting exercises variations that are less easy to cheat and insisting on proper technique for every repetition, especially later in the workout as fatigue sets in.
Conversely, with the right exercises it is possible to target weak links and address imbalances. Moreover, it is important to strengthen not just muscles but also connective tissues. Whilst young muscles respond quite readily to the demands placed upon them during sport, connective tissues are slower to adapt and tend to require a more concerted stimulus. The lag in the adaptation of tendons relative to muscles as young athletes are growing is a risk factor leading to the tendon overuse injuries that are prevalent in various sports, particularly around times of rapid growth. Once again, this is where dryland or off-field training can be indispensable. Strength training offers a potent means to fortify the tendons that trasmit forces between muscles and the levers of the body, as well as acting as shock absorbers and force magnifiers under different conditions.
Strength is the foundation for continued successful participation in sport. In earlier posts we made the case that regular strength training should be considered a necessity for girls to give them the boost they require to overcome the challenges that accompany puberty and avoid the negative downstream effects that otherwise follow. Strength is a decisive factor contributing to injury in adolescent girls, to a greater extent than for boys who enjoy free gains in lean mass and strength accompanying puberty. However, given the deficits in physical capacities exhibited by kids in general we should extend this recommendation to include boys. The ideal scenario is that both girls and boys make time for regular dryland or off-field training that includes strength development, commencing prior to puberty (around age 11 for girls, age 13 for boys) and continuing through their adolescent years.
