strength training

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ACL Injury Risk in Female and Youth Athletes: What Actually Matters (Part 2)

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Written by Michael Crawley, BSc, BPT, CSCS

Anterior cruciate ligament injuries are a significant issue in sport, particularly among female and youth athletes. Female athletes have a significantly greater incidence of ACL injury compared to males, with research suggesting the risk may be between 2 and 8 times higher depending on the population studied (Herzberg et al. 2017).

A number of factors have been proposed to influence this increased risk. These include both extrinsic factors such as playing surface, and intrinsic factors such as biological, structural, and physical characteristics. This article focuses on the intrinsic side of the equation.

If you have not read Part 1, where we break down how ACL injuries occur and what influences risk more broadly, you can start here: ACL Injuries: How They Occur, Who Is at Risk, and Why Training Quality Matters

The key intrinsic factors that may influence ACL injury risk in the female athlete include:

  • hormonal influences

  • biomechanics and structural considerations

  • strength and neuromuscular control

It is also important to recognize that surgery is not the only solution following an ACL injury. The appropriate approach depends on the athlete’s age, injury severity, and the presence of additional damage such as meniscal or cartilage involvement. Graft selection is also influenced by these factors and plays an important role in long-term outcomes.

Menstruation and Hormones

The menstrual cycle consists of three phases, each characterized by fluctuations in key hormones including estrogen, progesterone, and luteinizing hormone (Wojtys et al. 2002).

  • Follicular phase: approximately 9 days

  • Ovulatory phase: approximately 5 days, marked by peaks in estrogen and luteinizing hormone

  • Luteal phase: approximately 14 to 15 days, with elevated progesterone

Research in this area remains mixed. However, several studies have reported a higher incidence of ACL injuries during the ovulatory phase compared to other phases (Wojtys et al. 2002; Herzberg et al. 2017).

Wojtys et al. (2002) demonstrated a higher number of ACL injuries, marked as X on the figure above, in a group of young female athletes during the ovulatory phase. The mechanisms behind this relationship are varied and often disputed. At the neurological level, Kumar et al. (2013) demonstrated reduced reaction time to visual and auditory stimulus between the follicular and luteal phases.

From a structural perspective, the ACL contains estrogen receptors, and cell culture research has demonstrated that estrogen can influence the ligament’s collagen composition. It is proposed that this may increase knee joint laxity. Maruyama et al. (2021) examined knee laxity across the menstrual cycle and found increased anterior knee laxity during the ovulatory phase.

However, this difference was only observed when participants were grouped into those with genu recurvatum and those without it, meaning athletes whose knees hyperextend 10 degrees or more versus those who do not. This adds another layer of complexity, as it suggests that biomechanical factors such as hyperextension may interact with hormonal factors such as higher estrogen levels rather than acting independently.

Relaxin is another important peptide hormone that has been specifically linked to injury risk in female athletes. It appears to work synergistically with estrogen, contributing to changes in ligament laxity (Berger et al. 2023; Parker et al. 2024).

Relaxin exerts its effects in two key ways:

  • increases type 1 collagen degradation

  • suppresses collagen synthesis

Given that ligaments are composed of approximately 40 to 50 percent type 1 collagen, this provides a plausible mechanism by which relaxin may influence ACL integrity. Alterations in the collagen structure of the ligament are one proposed explanation for increased laxity and injury risk.

Parker et al. (2024) also highlight a practical consideration. Relaxin levels tend to peak around days 21 to 24 of the menstrual cycle. In a coaching setting, this may present as an athlete reporting unexplained musculoskeletal discomfort around the knee without a clear training-related cause. This is not something to overreact to, but it can serve as a useful opportunity for education, monitoring, or short-term modification of training.

Across the cycle, these hormonal fluctuations may contribute to changes in reaction time, ligament laxity, and available joint range of motion. While some research has explored the use of oral contraceptives to regulate these hormonal variations and potentially reduce ACL injury risk (Herzberg et al. 2017), the quality of evidence remains low and is often confounded by multiple variables.

More importantly, as Parker et al. (2024) point out, oral contraceptives are not without trade-offs. While they may influence hormones such as relaxin and estrogen, there are more accessible and lower-risk interventions available. For most young female athletes, this is not where the focus should be.

Which leads into the next major factor: strength and neuromuscular training.


Strength and Neuromuscular Training

As female participation in sport has increased over the past few decades, there has been a corresponding increase in injury rates. At the same time, training age and exposure to structured strength and conditioning within a gym setting has generally lagged behind that of male athletes.

Well-rounded strength and conditioning is not only a tool to support and improve performance in sport. It can have a profound effect on robustness and coordinative qualities, helping to mitigate injury risk.

For a deeper look at how strength training should be structured for younger athletes, see: Building a Strong Foundation: The Crucial Role of Youth Strength and Conditioning

In young female athletes, several characteristics have been associated with increased ACL injury risk (Collings et al. 2022):

  • lower strength ratios between hip adductors and abductors

  • reduced trunk control

  • higher countermovement peak force values

This highlights the importance of a complete strength and conditioning plan. As young athletes improve jumping ability and increase power output, the risk of ACL injury and other issues such as patellofemoral pain may also increase (Myer et al. 2015; Collings et al. 2022).

Training for these athletes must address several components:

  • maximal strength and power

  • jumping and landing mechanics and technique

  • strength capacity

  • energy system development

Sugimoto et al. (2016) demonstrated that neuromuscular programs that include a combination of strength training, jumping, trunk control, and coordination significantly reduce ACL injury risk in young female athletes.

Practical Exercise Examples

Below are five exercises that cover several key qualities related to performance and injury mitigation:

Adjusting variables such as volume, intensity, range of motion, and frequency can make exercises like these highly effective across a range of sports and athlete levels.


Adherence, Enjoyment, and the Training Environment

Several factors can impact adherence in young female athletes:

  • time

  • enjoyment

  • coaching expertise

  • equipment access

Research suggests that even two 30-minute sessions per week in-season can meaningfully reduce ACL injury risk, provided a more comprehensive program is completed in the off-season (Sugimoto et al. 2016).

Enjoyment and coaching quality are closely linked. Engagement in the gym setting can be a challenge, particularly for younger athletes. Incorporating competition, variability, and game-based elements can improve buy-in and training consistency.

Reaction, Coordination, and Game-Based Training

The following examples can be used to improve reaction time, coordination, and strength:

These drills can be implemented in pairs, relay formats, or with sport-specific variations. They also expose athletes to a broader range of movement patterns.

This ties closely into long-term athlete development principles, which are outlined further here:
Build the Athlete First: Why Youth Athletes Need Physical Literacy Before Sport Specialization

An additional benefit of implementing games with different constraints and equipment is the development of energy systems and exposure to a wider range of motor patterns. The importance of this is two-fold.

  1. Fatigue has been shown to impact landing control and hip-to-ankle force dissipation in female athletes (Mancino et al. 2024). Improving overall capacity can enhance an athlete’s ability to maintain reaction time and landing mechanics over longer periods.

  2. Game and exercise constraints can also help offset the repetitive, high-volume actions seen in many sports. This becomes even more relevant in athletes who specialize early in a single sport.

Luo et al. (2025) found that early sport specialization increases injury risk, reduces long-term performance, and negatively impacts psychological outcomes. With a creative and experienced coach, the gym setting can serve as a valuable environment to address these gaps.

That said, even with a well-informed and diligent athlete who engages in strength training and participates in multiple sports, ACL injuries can still occur.


Surgical Route and Graft Selection

When a discussion has been made and surgery is deemed the best option, the next decision is graft selection. The importance of this choice lies in the fact that it is one of the few modifiable factors (Duchman et al. 2017). For the young female athlete, variables such as sex, age, and sporting demands cannot be changed.

The main graft options include:

  • Autograft: tissue harvested from the athlete’s own body. Common options include hamstring tendon (HT), bone-patellar tendon-bone (BPTB), and quadriceps tendon (QT)

  • Allograft: donor tissue. Options can include tibialis anterior, Achilles tendon, hamstring, or patellar grafts (Duchman et al. 2017)

Pinheiro et al. (2022) conducted a large analysis in female athletes and found that bone-patellar tendon-bone grafts had a lower incidence of graft failure compared to hamstring grafts. This becomes more nuanced when age is considered.

Mancino et al. (2024) reported that BPTB grafts had lower re-rupture rates in females aged 15 to 20 compared to hamstring autografts. However, in athletes aged 21 and older, outcomes between BPTB and hamstring grafts were similar.

Graft revision risk is also an important consideration. Pinheiro et al. (2022) found that revision rates were 1.8 times higher in hamstring grafts compared to BPTB, increasing to 2.8 times in females under 18. This is particularly relevant, as revision surgeries tend to produce poorer outcomes compared to primary ACL reconstruction (Meena et al. 2024).

More recent evidence suggests that quadriceps tendon grafts produce comparable outcomes in terms of knee stability, functional performance, and re-tear risk (Meena et al. 2024).

Previous injury history should also influence graft selection. Lazarides et al. (2018) reported that a history of moderate to severe patellar tendinopathy was associated with increased graft failure when using BPTB grafts.

Similarly, hamstring autografts may contribute to post-surgical return-to-sport challenges (Bouzekraoui Alaoui et al. 2025), including:

  • persistent strength deficits compared to the uninvolved side

  • reduced maximum effective angle, a proxy for hamstring function and potential injury risk

In athletes with a history of recurrent hamstring strains or existing strength deficits, harvesting a hamstring graft from the involved side should be carefully considered. This may further complicate the already challenging process of restoring hamstring strength and function during rehabilitation.


Additional Surgical Consideration: LET

Another surgical consideration is the lateral extra-articular tenodesis (LET), which may provide additional protection against re-injury. Recent research has identified specific factors where LET can help reduce risk and may be used as an added layer of structural support (Meena et al. 2024).

These factors include:

  • increased general knee ligament laxity

  • high tibial slope and increased knee hyperextension

  • return to high-demand sport

  • younger age

These considerations are particularly relevant for the young female athlete. As discussed throughout this article, hormonal influences on ligament laxity, along with structural characteristics such as knee hyperextension, are commonly observed in this population.

Using appropriate graft selection alongside LET where indicated provides an additional layer of structural support and may improve long-term outcomes in higher-risk athletes.

Summary

There is a complex interplay between hormonal, structural, and neuromuscular factors that may increase ACL injury risk in young female athletes. While many aspects of the research still require further clarity, it is clear that both modifiable and non-modifiable factors are at play.

There are several practical approaches that can help mitigate risk while also improving performance. As participation in female sport continues to grow, appropriate exposure to education, training, and support systems is no longer optional. It is essential.

Actionable Takeaways

  • Pre-season screening and strength testing, alongside ongoing in-season monitoring, can help identify and manage risk

  • Strength and neuromuscular training should be prioritized, including development of landing mechanics and force absorption

  • Coaches can use warm-ups and training creatively to expose athletes to a wider range of movement patterns, which can improve engagement and reduce repetitive strain

  • Avoiding early sport specialization where possible can support long-term performance and reduce injury risk

  • Graft selection should consider individual factors such as age and injury history, with input from both the physio and orthopaedic surgeon

  • Discussing additional surgical options, such as LET where appropriate, may improve outcomes in higher-risk athletes

  • Education for both athletes and parents is key. Increasing awareness and training age can have a meaningful impact on long-term development and injury mitigation

For athletes or parents looking for more structured support, this is where individualized assessment and programming can make a meaningful difference: Book an Initial Assessment

What Actually Happens During an Initial Assessment?

Written by Evelyn Calado, MKin, CSCS, RKin

If you’ve ever hesitated to start training because you didn’t know what to expect from that first session, you’re not alone. At Avos Strength, we treat the initial assessment as one of the most important parts of the entire training process. Not because it’s a test, or something you can pass or fail, but because it lays the foundation for everything we do moving forward. It’s how we get to know you, your goals, your movement, and how we can best support you.

Here’s what actually happens during an initial assessment with us.

It’s a 55 Minute, One-on-One Session

Most initial assessments are done in person. We also offer virtual options for remote clients. Whether we’re working with you at the gym or through a screen, the goal is the same: get a clear picture of where you’re at so we can build something that’s right for you.

It Starts With a Conversation

Before we even get moving, we sit down together and go through your intake form. And yes, it’s detailed. We ask for it to be completed at least 24 hours in advance because we actually review it before the session.

We go over:

  • Your injury history and relevant medical conditions

  • Sports background, hobbies, and training experience

  • Your goals, both short-term and long-term

  • Any current pain, discomfort, or limitations

  • Your preferred training setup (in-person, hybrid, remote)

This isn’t just a checklist. It’s a conversation. We want to hear your story, understand what brings you in, and talk about how we can help. That also includes discussing which coach might be the best fit, based on your needs and our availability.

Movement Screen and Table Assessment

Table assessment being performed during an initial assessment at Avos Strength

After the consult, we begin assessing movement.

We typically look at:

  • Posture and gait

  • Basic functional movements (like squats, toe touches, and rotation)

  • Joint mobility and range of motion on the table

This gives us an idea of how you move in space, where you may feel limited, and what patterns we should be aware of when designing your program. For remote assessments, this part is adapted as best we can based on your space and setup.

This Is Not the Avos Performance Battery

Our initial assessment is different from the Avos Performance Battery, which is a full 90 minute performance testing session that includes a written report. This assessment is about gathering foundational information, not performance metrics. It’s the first building block in your training process, not a test.

What Happens With the Remaining Time?

Depending on how the session flows, we may use the last 10 to 20 minutes to go through some light drills, address pain points, or suggest a few exercises to get you started.

Sometimes we’ll do a bit of strength or movement testing, just enough to give us some useful data without overwhelming you on day one.

Why We Do It This Way

Your initial assessment helps us:

  • Build rapport and trust

  • Understand how you move

  • Identify restrictions or red flags

  • Gather everything we need to design a personalized program

Without this step, we’d be guessing. And that’s not how we operate. Your coach takes the time before, during, and after this session to make sure we’re starting from the right place.

How You Should Feel After

You should walk away feeling heard. You should feel supported. Ideally, you feel excited, not nervous, to start training and build something that’s going to serve you long term.

Training is a skill. It’s a habit. It’s a way of taking care of your body so you can keep doing the things you love, whether that’s playing sports, being active with your family, or just moving better every day.

Common Misconceptions We Hear

“I feel like I’m being judged.”
You’re not. There are no wrong answers in this process. If your hips move a certain way, or your shoulder is limited, that’s all information we use to help you.

“I don’t think I’m fit enough to be assessed yet.”
That’s exactly why we do assessments. You don’t need to be fit. This is about meeting you where you are and giving us a starting point to work from.

“What if I fail?”
You can’t fail. This isn’t a test. It’s a snapshot of where you’re at today.

A Structured, Individualized Approach

Everything we collect goes into your client file, not a generic template. Your program is built from the ground up based on your movement, your goals, your limitations, and your training setup.

Every Avos coach follows this system. Our junior coaches go through a structured mentorship before ever leading assessments on their own, and we continue to support them with feedback and review to maintain high standards.

There are no shortcuts. And that’s the point.


The first session isn't about being perfect. It's about getting started the right way; with a coach who sees you, listens to you, and builds something with you.

If you're ready to take the next step, explore our training options to find the approach that best fits your goals.

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Is Two Days per Week of Strength Training Enough for Longevity?

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Written by Evelyn Calado, MKin, CSCS, RKin

If you look at most public health guidelines, the answer seems straightforward. Adults are advised to perform muscle-strengthening activities at least two days per week. This recommendation appears in Canadian, American, and international guidelines and applies to both adults and older adults.

But this raises an important question.

Is two days per week simply the minimum needed to check a health box, or is it actually enough to support long-term health, independence, and longevity?

The short answer is that two days per week can be enough, but only under specific conditions. Frequency alone does not determine whether strength training meaningfully impacts longevity. The quality and intensity of the stimulus matter far more than the number of days on a calendar.

What the Guidelines Actually Mean

Public health recommendations are designed for populations, not individuals. Their goal is to identify the lowest effective dose of activity that meaningfully reduces disease risk at a broad scale.

When guidelines recommend strength training twice per week, they are not suggesting that this is optimal for strength, muscle mass, or performance. They are identifying a threshold below which health risks increase, particularly as we age.

In other words, two days per week is a floor, not a ceiling.

Strength Training and Longevity: What the Research Actually Shows

Research consistently shows that resistance training is associated with lower all-cause mortality, reduced cardiovascular disease risk, and improved long-term health outcomes. From a public health perspective, even relatively small amounts of strength training appear to provide meaningful benefit.

However, it is important to be precise about what these findings actually represent.

Most large-scale longevity studies are designed to identify the minimum effective dose of strength training required to reduce population-level risk. They are not designed to define what is optimal for building strength, preserving muscle mass, or maximizing physical capacity across the lifespan.

In this context, it is true that one to two well-performed strength training sessions per week capture a substantial portion of the longevity benefit observed in epidemiological research. Beyond that point, additional sessions do not appear to reduce mortality risk in a simple, linear fashion.

This does not mean that training more is unnecessary, nor does it suggest that strength beyond a certain point stops being valuable. It simply reflects how longevity is measured in large populations.

For individuals interested in aging well, remaining strong, and protecting themselves against injury, disability, and loss of independence, the goal should not be to meet the minimum dose, but to build and maintain as much usable strength as possible over time.

Longevity vs Capacity: Two Different Goals

It is worth separating two concepts that are often conflated.

Training for longevity focuses on reducing disease risk and maintaining basic function. Training for capacity focuses on building strength, muscle mass, power, and resilience.

While two strength sessions per week may be sufficient to support longevity-related outcomes and can improve strength and muscle mass, they are often not the most effective approach for maximizing those qualities long term, particularly in trained individuals or as we age.

From a coaching perspective, the objective is not to do the least amount of work required to stay alive. The objective is to build a body that remains capable, robust, and adaptable for decades.

That typically requires more than the minimum.

Grip Strength, Brain Health, and Why Strength Is More Than Muscle

One of the most compelling demonstrations of strength’s relationship to long-term health comes from research on grip strength.

A large prospective study using data from nearly 500,000 adults in the UK Biobank examined the association between hand grip strength and dementia incidence. Grip strength, often used as a proxy for overall muscular strength, was found to be strongly and inversely associated with dementia risk.

Individuals in the lowest quartile of grip strength had a 72 percent higher incidence of dementia compared to those in the highest quartile.

This finding is important for two reasons.

First, it reinforces that muscular strength is closely tied to neurological and cognitive health, not just physical capability.

Second, it highlights that simple, measurable indicators of strength can reflect deeper systemic health. This is one reason grip strength is included in assessments such as the Avos Performance Battery. It provides insight into overall robustness, not just hand function.

Strength training, when performed with sufficient intensity, appears to play a meaningful role in preserving mobility, independence, and long-term brain health.

Strength Still Matters Even When Cardio Is “Good Enough”

Another frequently overlooked point is that strength contributes to longevity independently of cardiovascular fitness.

A long-term study following approximately 1,500 men over the age of 40 with hypertension for nearly 18 years examined the relationship between muscular strength, cardiorespiratory fitness, and mortality risk.

The findings were striking.

Even among men who were only in the bottom half of cardiorespiratory fitness, those in the top third for muscular strength had an almost 48 percent lower risk of all-cause mortality compared to those in the lowest strength group.

In other words, being strong mattered, even when aerobic fitness was not exceptional.

The lowest mortality risk was observed in individuals who were both strong and aerobically fit, but strength alone still provided a substantial protective effect. This reinforces the idea that resistance training is not optional if longevity is the goal.

Is Two Days per Week Enough in Practice?

This is where nuance matters.

For many adults, particularly those with limited time, two well-designed strength training sessions per week can meaningfully support long-term health. When performed with sufficient intensity and progression, this approach can maintain and often improve key outcomes such as:

  • Muscular strength

  • Muscle mass (particularly in untrained individuals or those returning to training)

  • Bone health

  • Joint capacity and tissue tolerance

  • Metabolic health

  • Overall function and independence as you age

However, outcomes depend on the goal, training history, and how the sessions are structured.

If an individual’s goal includes maximizing lean muscle mass, strength, power, or creating a larger buffer against age-related decline, training more than twice per week is often useful. This is not because two days “doesn’t work,” but because additional sessions often make it easier to accumulate more high-quality weekly training volume, practice key movement patterns, and progress without excessively long sessions.

Frequency alone does not determine effectiveness. What matters is whether training provides enough mechanical tension, effort, and progression to challenge the tissues that decline most rapidly with age.

Using five-pound dumbbells indefinitely, avoiding effort, or treating strength training as light activity rather than progressive overload is unlikely to produce meaningful adaptation.

Two high-quality sessions can outperform several low-effort ones. But for many people seeking to age strong, three to four sessions per week can be a practical way to accumulate more total weekly work and drive continued progress, especially once the “beginner gains” phase has passed.

Aging Changes the Equation

As we age, muscle protein synthesis becomes less responsive, strength declines faster than endurance, and power loss accelerates. This means that intensity and intent become increasingly important over time.

For older adults, two days per week may still be sufficient, but only if:

  • Exercises are appropriately loaded

  • Movements challenge balance and coordination

  • Strength is trained through meaningful ranges of motion

  • Progression is maintained where possible

Training “often enough” is not the same as training “effectively.”

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ACL Injuries: How They Occur, Who Is at Risk, and Why Training Quality Matters (Part 1)

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Written by Michael Crawley, BSc, BPT, CSCS


BACKGROUND

Anterior cruciate ligament injuries (ACLI) are often viewed as sudden, unavoidable events that are “fixed” through surgery. In reality, both injury risk and long-term outcomes are strongly influenced by training quality, rehabilitation approach, and the decisions made before and after injury.

This article highlights the complexity of ACL injuries, explains how and why they occur, and outlines key training and rehabilitation considerations that influence risk and return to sport outcomes. While ACL injuries are often discussed in isolation, they are rarely simple knee injuries, and successful outcomes require a broader, long-term view.

The information presented is intended to provide practical, actionable insight for a range of athletes and stakeholders, including:

  • Youth multi-sport athletes and their parents

  • High-level collegiate and professional athletes

  • Competitive recreational athletes of all ages

ACLI have increasingly been described as an epidemic across both amateur and professional sport. Several studies report that ACL injuries account for approximately 50 percent of knee injuries. Over the past 10 to 20 years, female and youth athletes have experienced the largest increase in incidence. Childers et al. (2025) identified female adolescent athletes as the highest-risk group, with a 1.5-fold increased risk compared to their male counterparts.

Importantly, ACL injuries often occur alongside meniscal and cartilage damage. These associated injuries substantially increase the risk of long-term joint degeneration, including osteoarthritis and the need for total knee replacement (Petushek et al. 2019). This added complexity also plays a significant role in surgical decision-making and long-term outcomes.


HOW DOES THIS HAPPEN

ACL injuries generally fall into two categories:

  1. Contact injuries

  2. Non-contact injuries, which account for nearly 80 percent of all ACL ruptures (Beaulieu et al. 2023)

Most non-contact injuries occur during high-speed or high-load movements such as single-leg landings, rapid deceleration, or sharp changes of direction. These movement patterns are common across many sports and can occur both during high-intensity competition and through repeated lower-intensity exposures over time.

Sports such as basketball, soccer, netball, and rugby place consistent demands on these movement patterns, emphasizing the importance of preparing athletes not only for isolated high-risk moments, but also for cumulative loading over a season.


RISK FACTORS AND TRAINING IMPLICATIONS

ACL injury risk is influenced by a combination of anatomical, biomechanical, and training-related factors. While some risk factors cannot be changed, many can be meaningfully influenced through education and training.

Female Athlete Considerations

In female athletes, structural features of the tibia, such as posterior tibial slope, along with hormonal influences on ligament laxity, contribute to an increased risk of ACL injury (Kikuchi et al. 2022; Beaulieu et al. 2023).

While these factors cannot be modified, they highlight the importance of early education for young female athletes and their coaches. Building awareness around neuromuscular control, strength development, and movement quality is a critical component of risk reduction.

Playing Surface

Research examining the influence of playing surface has produced mixed findings. However, some studies report higher ACL injury rates in NFL athletes competing on artificial surfaces compared to natural grass (Hershman et al. 2012).

Although athletes cannot always control the surface they compete on, training exposure can be diversified. Incorporating training on a variety of surfaces may help improve adaptability and tolerance to different loading conditions prior to competition.

Fatigue and Repetitive Loading

Emerging evidence suggests that ACL rupture does not always result from a single traumatic event. Fatigue and repetitive sub-maximal loading may contribute to progressive ligament failure over time (Wojtys et al. 2016).

From a training perspective, building tissue capacity in key muscle groups such as the hamstrings, quadriceps, calves, and adductors may increase tolerance to repeated stress and reduce injury risk.

Whole-Body Strength and Neuromuscular Control

Although ACL injuries occur at the knee, load can be transmitted from both the top down and bottom up through the kinetic chain. Poor three-dimensional strength across the trunk, hip, knee, and ankle can increase stress on different portions of the ACL (Beaulieu et al. 2023).

Training that develops strength in multiple planes of motion, both in isolated exercises and integrated movement patterns, helps improve robustness and neuromuscular control.

For example, multi-directional jumping exercises can target trunk, hip, knee, and ankle coordination simultaneously:


WHAT IS CONSIDERED SUCCESSFUL ACL REHABILITATION AND HOW IS IT ACHIEVED

Over the past decade, the definition of successful return to sport (RTS) following ACL injury has evolved. A well-regarded Canadian kinesiologist, Carmen Bott, emphasizes that simply returning to sport is not the same as returning successfully.

Long-term data highlight the difficulty of maintaining sport participation following ACL injury. Pinheiro et al. (2022) reported that among elite athletes followed over five years, participation at the same competitive level declined from 75 percent in year one to just 20 percent by year five.

Outcomes are even less favorable in competitive amateur athletes. Approximately 65 percent return to pre-injury level, with overall return to competitive sport roughly 10 percent lower (Nwachukwu et al. 2019).

Following a well-structured, progressively loaded strength and conditioning program can enhance both physical capacity and confidence during rehabilitation. A simplified progression may include:

This progression represents only a snapshot of a rehabilitation process that commonly spans 9 to 12 months. Progression should be goal-oriented rather than time-driven, with athletes meeting clearly defined prerequisites before advancing.


TO CUT OR NOT (NOT MEDICAL ADVICE)

When an athlete is diagnosed with an ACL injury, the immediate assumption is often that surgery is required. Indeed, 98 percent of orthopaedic surgeons recommend ACL reconstruction for athletes aiming to return to sports involving running, cutting, and jumping (Weiler et al. 2015).

However, surgery is not always the appropriate choice. Non-operative management may be suitable depending on several factors (Komnos et al. 2024), including:

  • Individual expectations and current sport level

  • Presence of concomitant injuries such as meniscal or cartilage damage

  • Degree of knee laxity and perceived instability

Fitzgerald et al. (2000) classified individuals into three groups:

  1. Copers: return to pre-injury level of sport

  2. Adapters: return to a reduced level to avoid instability

  3. Non-copers: unable to return due to persistent instability

A notable example is a Premier League footballer who returned to play eight weeks after a complete ACL rupture without surgery (Weiler et al. 2015). While this represents a single case, it highlights the importance of individualized decision-making.

What Does This Mean for Non-Professional Athletes?

Athletes outside professional systems should:

  • Ask detailed questions about the structures involved in their injury (ACL only vs associated damage)

  • Communicate subjective symptoms such as instability, confidence, or locking

  • Clarify long-term goals, whether returning to competition or maintaining an active lifestyle

  • Consider an initial period of structured rehabilitation before committing to surgery, particularly when instability is not present

In the Premier League case study, the athlete consulted three surgeons, two of whom recommended surgery, while one supported a conservative rehabilitation-first approach. This underscores the value of informed discussion and shared decision-making.


SUMMARY AND KEY TAKEAWAYS

  • ACL injuries are complex and influenced by multiple interacting factors including age, sex, sport demands, training exposure, and movement quality.

    • Educating female athletes about menstrual cycle considerations and ligament laxity may be beneficial.

    • Monitoring training load during high knee-stress activities is important.

    • Developing tissue capacity through comprehensive strength training can enhance tolerance to stress.

  • Returning to previous levels of sport remains challenging, particularly for non-professional athletes.

    • Rehabilitation should be thorough and guided by experienced practitioners.

    • Successful return to play depends on strength, neuromuscular control, and power that match sport-specific demands.

  • Surgery is not the only option.

    • Decisions should be made collaboratively between the athlete, physiotherapist, and surgeon.

    • Clear communication around injury extent and long-term goals leads to better outcomes.


Looking for Individualized Support?

If you’re currently dealing with an ACL injury, returning from surgery, or unsure how to safely progress your training, working with an experienced coach can make a meaningful difference.

Michael works closely with athletes across all levels and has extensive experience supporting ACL rehabilitation and return-to-sport training in collaboration with physiotherapists and medical professionals.

If you’d like to explore whether coaching support is right for you, you can book an initial assessment here.


PART 2: WHAT TO EXPECT

The next article will focus specifically on female and youth athletes and will explore:

  • Graft selection considerations when surgery is required

  • The role of prehabilitation in improving long-term outcomes


References

Beaulieu, M. L., Lamontagne, M., Xu, L., & Li, G. (2023). Loading mechanisms of the anterior cruciate ligament. Sports Biomechanics, 22(1), 1–29. https://doi.org/10.1080/14763141.2021.1916578

Childers, J. D., Weiss, L. J., Pennington, Z. T., Nwachukwu, B. U., & Allen, A. A. (2025). Reported anterior cruciate ligament injury incidence in adolescent athletes is greatest in female soccer players and athletes participating in club sports: A systematic review and meta-analysis. Arthroscopy, 41(3), 774–784.e772. https://doi.org/10.1016/j.arthro.2024.03.050

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Why Women Should Think Twice About Cold Plunges

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Written by Evelyn Calado, MKin, CSCS, RKin

Cold plunges are everywhere right now. Scroll through social media, walk into any boutique gym, or listen to the latest biohacking podcast, and you're bound to hear someone praising the "recovery magic" of ice baths. But there's a problem: this recovery trend is not built for female physiology. And no one seems to be talking about it.

As a woman, especially one training hard and aiming to get stronger, faster, or more resilient, you need to know this: cold plunges can actually hinder your progress.

The Hype vs. The Science

The fitness industry often pushes one-size-fits-all solutions that are, in reality, designed around male physiology. Cold water immersion is no exception. The main argument for it is that it reduces inflammation and muscle soreness. But what’s rarely discussed is that blunting inflammation also blunts adaptation—the very thing you're working hard for in your training.

A key study published in The Journal of Physiology (2015) found that post-exercise cold water immersion significantly reduced long-term gains in muscle mass and strength by suppressing key anabolic signaling pathways. In simpler terms, jumping into a cold plunge after lifting can shut down the processes your body needs to get stronger.

The Female Factor: Why It’s Worse for Women

Dr. Stacy T. Sims, PhD, exercise physiologist and author of ROAR, explains that women already have a more robust anti-inflammatory response, largely due to estrogen. This is great for recovery in general—but it also means that adding more inflammation-suppressing strategies (like cold plunges) can tip the balance too far.

Here’s what that means:

  • Estrogen helps buffer inflammation, so you don’t need the added suppression from cold water.

  • Cold plunges inhibit mTOR signaling, a critical pathway for muscle protein synthesis. Since women already face challenges building and maintaining lean muscle due to fluctuating hormone levels—particularly during the high-progesterone phase of the menstrual cycle—this further suppresses adaptation.

  • Women have a shorter post-exercise anabolic window. That means the timing and environment for recovery matter more. Cold exposure immediately post-training can close this window prematurely.

Heat, Not Cold, Supports Female Recovery

Dr. Sims recommends heat-based recovery tools for women, such as sauna use or hot baths. Heat increases blood flow, supports mitochondrial adaptations, and promotes muscle repair without blunting the natural signals for strength and hypertrophy.

Where cold shuts down your body’s growth processes, heat helps amplify them—especially beneficial for women looking to increase muscle mass, endurance, and overall athletic performance.

Let’s Talk About the Real Issue

This isn’t just a science debate. It’s a visibility problem. Right now, women are being told to do what’s trending without being informed of how it might hurt them. The fitness industry is ignoring female physiology. And it’s not okay.

If you're a woman who trains, lifts, runs, or just wants to be strong and healthy, you deserve better than a one-size-fits-all recovery strategy. You deserve recovery tools that actually work with your body, not against it.

So the next time someone tells you to jump into a cold plunge for recovery, remember that your physiology is different. And according to Dr. Stacy Sims and peer-reviewed research, cold plunges may be doing more harm than good for women.

Let’s change the conversation.

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The Only Two Supplements Most Athletes Actually Need

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Written by Evelyn Calado, MKin, CSCS, RKin

 

Walk into any supplement store and it’s overwhelming. Rows of pre-workouts, amino acids, test boosters, fat burners, and other shiny tubs promising to change your game overnight. But the truth is, most of it is noise.

At Avos Strength, we keep it simple. If you’re training hard and want to support performance, recovery, and overall health, there are only two supplements that actually matter.

And they aren’t flashy.

1. Protein Powder: The Most Underrated Tool in the Game

You don’t need protein powder to build muscle, but it can make it a lot easier to get enough protein — especially if you're busy, training often, or just not eating enough.

Protein is the building block of muscle. Without it, recovery slows down and progress stalls.

The general recommendation for active individuals and athletes is 1.6 to 2.0 grams per kilogram of body weight per day. If you're trying to put on muscle or training at a high volume, aim for the higher end of that range.

This means a 70-kilogram athlete should be getting 112 to 140 grams of protein daily. That’s a lot of chicken breast and Greek yogurt — and that’s where a high-quality protein powder can help.

Look for a product that:

  • Lists all essential amino acids (a complete protein)

  • Contains at least 20 to 25 grams of protein per serving

  • Comes from a reputable source like whey isolate, casein, or a solid plant-based blend with a full amino acid profile

If you are a competitive athlete, make sure your product is third-party tested and carries a Safe for Sport stamp such as NSF Certified for Sport or Informed Sport. This ensures there are no banned substances and that what's on the label is actually in the product.

Using protein powder post-training or to fill in gaps throughout the day is one of the easiest and most cost-effective ways to hit your daily targets.

2. Creatine: The Most Researched Supplement in the World

Creatine is a naturally occurring compound made from three amino acids: arginine, glycine, and methionine. It’s stored in your muscles and used to quickly regenerate ATP, the energy source your body relies on for short, powerful efforts like lifting, sprinting, and jumping.

If there’s one supplement that lives up to the hype, it’s creatine. It's been studied for over 30 years and is backed by more peer-reviewed research than any other supplement on the market.

Creatine helps you:

  • Perform more reps at a given load

  • Recover faster between explosive efforts

  • Improve high-intensity performance over time

What’s even more exciting is the emerging research around brain health. Studies now suggest creatine may improve cognitive function, especially under sleep deprivation or mental fatigue, and may play a protective role in aging populations.

How to Take It

  • For muscle saturation: Take 5 grams of creatine monohydrate per day. No need to load or cycle it.

  • For brain health benefits: Newer research suggests 10 to 20 grams per day may be more effective, though higher doses should be discussed with a healthcare provider or sport nutritionist.

As with protein powder, if you're a competitive athlete, use a creatine product that is NSF Certified for Sport or Informed Sport. This ensures the supplement is free from banned substances and batch tested for safety.

Creatine is:

  • Safe

  • Inexpensive

  • Naturally occurring (your body makes it, and you also get it from meat and fish)

  • Non-hormonal

  • Effective for both men and women

Just take it consistently. It doesn’t need to be timed perfectly with your workout, and you don’t need a fancy pre-workout mix to get the benefits.

Don’t Get Caught in the Supplement Hype

BCAAs, pre-workouts, collagen, fat burners — they all have their place in the marketing stream, but they are not essential.

If you’re on a budget or just want to stick with what works, protein and creatine will give you the most return on your investment. Everything else is secondary.

And most importantly, no supplement replaces hard training, smart programming, and real food.

Build your foundation first. Let supplements support that — not define it.