**If I return to lifting heavy weights after a total hip replacement, does my implant risk ripping itself out of the socket?** This is the key question I wanted to know as I return to strength training post-total hip replacement. This article tries to answer that question.

One key challenge for athletes recovering from a hip replacement is the lack of clear, accessible information on how quickly they can return to training and what volume or weight is safe to lift. For context, I'm a 36-year-old male who had a posterior approach total hip replacement about 3.5 months ago at the time of writing, and I wanted answers!

**TLDR:** If you want just the data I arrived at, here is the graph showing how I estimated what I can probably safely lift based on levels of bone osteointegration (Though please also read the disclaimer below as these could be wrong or risky to adopt. I am not a clinician, sports, or medical professional, and this article is not clinical or medical advice.)

*I also include these graphs individually, plus the reasoning behind the calculations, etc, below. The main thing to note is how much stronger the joint is at months 3-4 onwards compared to the early recovery.*

While I understand that the materials used for implants are designed to be mechanically strong (I've chosen the Oxinium implant, which performs well in terms of wear and load), I’m also conscious of the need for the implant to integrate with the bone, which takes time. It's difficult to predict the weights the implant can handle at different stages of recovery.

The purpose of this article is to share some basic calculations I’ve done to estimate what may be safe to lift during my recovery.

**Listen to a "deep dive" conversation talking about this article:**

**In this article:**

**Understanding Osteointegration:**Why bone-implant integration is the critical limiting factor in early recovery.**Calculating Shear and Compression Forces:**Estimating the maximum forces that a hip implant can safely withstand at different stages of recovery.**Applying Force Multipliers:**How specific movements like squats and deadlifts create varying levels of stress on the hip joint, and how I calculated safe weight limits.**Other Risks:**How these calculations are simplified, and other risk factors influence safety, and my judgement call on what to do personally in the face of these risks.**The Role of Recovery and Surgeon Guidance:**Why these calculations were just one part of my decision-making process, alongside expert medical advice.**Considering Long-Term Wear:**The balance between heavy lifting and the potential for increased wear on the joint, and how I’m factoring that into my training decisions.

By sharing my journey, I hope to offer some insights to others facing a similar challenge. However, remember that these are personal calculations and should not replace professional medical advice.

**Disclaimer**

**I am not a clinician, sports, or medical professional, and this article is not clinical or medical advice. Please take the information in this post AS-IS.**

**The calculations in this post are based on numerous assumptions, some of which could be wrong. I’ve tried to base these on sensible, researched assumptions, which I will outline in the article. However, as with any model, if any of the assumptions are incorrect, the results could be inaccurate, potentially by a large margin. It’s also important to remember that the human body varies from person to person. Some individuals may recover more quickly, while others might take longer, so what is safe for one may not be safe for another. This article is not intended as a guide, nor is it medical advice. You should always consult your surgeon and physiotherapist and not rely on the numbers in this blog. What I’m doing here is simply sharing my own decision-making process for informational purposes only. Please ensure that your surgeon and qualified physiotherapist guide your recovery process. Lifting weights that are unsafe for your stage of recovery could lead to catastrophic consequences, including implant failure, revision surgery, and serious health issues. **

**And 100% do not go and think, "Andrew's graph says 400KG, so it's safe for me to go and YOLO a 400KG 1RM". That is not the spirit of this article!**

**Thinking About the Problem**

**Osteointegration as the limiting factor**

The force that my hip can take is not just based on the strength of the implant itself but also its durability and the process of osteointegration, which is the level and success of the implant’s integration with the bone over time. Osteointegration is a gradual process, and until it's fully established, the implant’s ability to bear weight will be restricted by the strength of this bond.

Although this post focuses primarily on the implant and osteointegration, it's also important to remember that muscular recovery plays a big part of how quickly and how heavy I could return to training. Muscle strength and coordination are essential to your overall recovery, and while I’m not delving into that here, I work closely with my physiotherapist and coach to ensure we're clear on what is safe from a muscular perspective. Ignoring muscle recovery could lead to complications, so it’s something that must not be overlooked during rehabilitation.

**Deciding what forces matter in my estimations**

From a mechanical and wear standpoint, my Oxinumum implant is tested for 45 million cycles with 400 kilograms of force passing through the joint. This is roughly equivalent to deadlifting 100 kilograms when accounting for body weight and the physics involved in a hip-hinge movement, such as moment arms and leverages.

This tells us about the ability to handle wear with a reasonable force through many repetitions over time, but it does not tell us much about the more extreme forces that the implant can handle.

Compressive and shear forces play a role when performing movements involving the hip joint, and both of these forces affect the implant’s performance and durability. So before I can model the scale of the weights I can lift at each stage of recovery, I first need to calculate the fully-osteointegrated bone-implant interface strength when put under shear and compressive forces.

**Shear Strength**

Shear force occurs when two surfaces slide past each other, creating stress along the interface.

It was initially challenging to find specific levels of shear and compressive force that the joint could withstand, but I found two relevant studies on hydroxyapatite-coated implants, which is relevant as Oxinium implants are commonly paired with this coating. In a study by Hayashi et al. (1993) and another by Castellani et al. (2010), they demonstrated that these implants could withstand shear forces ranging from 4 to 12 MPa. Both have different materials and mechanisms, but this provides a useful benchmark for understanding the kinds of forces an osseointegrated implant may endure.

A megapascal (MPa) measures pressure or stress, indicating how much force an implant can handle per unit area. For implants, MPa values help quantify their resistance to forces like shear or compression. While MPa measures force per area, implant size matters too—larger implants spread forces over more surface area, reducing stress, whereas smaller implants concentrate it, affecting overall durability.

Therefore 4-12 Mpa doesn't yet make much sense to us on it's own, and to calculate what this means in terms of force, we need to convert it to newtons based on the surface area of the implant. Given most Oxinium implants have an acetabular cup surface area of 5000-10,000mm², let's go with the lower end of that of 5000mm².

Let's now convert this 4-12 MPa to kilograms accounting for the 5000² surface area of the outer shell of the implant bone-implant interface:

**Lower Range:**

Force = 4MPa x 5000mm² = 20,000 N

20,000 N = 2,038 kg**Upper Range:**

Force = 12MPa x 5000mm² = 60,000 N

60,000 N = 6,118 kg

For the sake of our estimates, I will be risk-averse and go with the lower number calculated based on 4Mpa. Picking the lower range means when my implant is fully osseointegrated, my bone-implant interface can likely take the lower end of this range: **2,038 ****kg of shear force.**

**Compressive Strength**

Compressive Strength is the maximum pressure an implant can handle before structural failure, particularly relevant to load-bearing joints like hip implants.

A study by Kurniawan et al. (2011), using finite element analysis, examined the bone-implant interface under varying degrees of osseointegration. The analysis showed that, at full osseointegration (100%), the bone-implant interface can handle up to 70 MPa of stress at critical regions. This value provides a realistic estimate for the compressive strength of an acetabular cup implant.

To convert this to force, using the assumption of a 5,000 mm² acetabular cup interface, we can calculate:

- Force = 70 MPa x 5000 mm² = 350,000 N

350,000 N = 35,678 kg of compressive load capacity.

This gives us a clearer picture of the significant compressive forces these implants can withstand, reinforcing the reliability of Oxinium implants even under high-stress conditions. The combination of strong material properties and surface coatings like hydroxyapatite helps maintain implant stability and integrity

For tolerance, let's half this 35,678 kg number and choose **17,839 kg** as our bone-interface maximum allowable compressive force limit.

**Which is the weak link, the bone-implant interface, or the materials**

While Oxinium and 10-XLPE materials used in hip implants are engineered to withstand incredibly high forces—well beyond the stresses encountered during daily activities—it's important to remember that the bone-implant interface is much weaker. The materials themselves, like Oxinium, have compressive strengths exceeding 2,000 MPa, and the 10-XLPE inner liner (A strong plastic) is highly wear-resistant with compressive strengths around 20-30 MPa.

I'll show you how these MPa figures translate into kilograms. For these calculations, we'll use a surface area of 3000mm² as the inner surface of the plastic liner will have a smaller surface area than the full acetabular implant, which is in contact with the bone.

**Oxinium force capacity:**

- Force = 2,000 MPa x 3000mm² = 6,000,000 N

6,000,000 N = 612,244 kg

**10-XLPE (Poly Liner) force Capacity:**

- Force = 20 MPa x 3000mm² = 60,000 N

60,000 N = 6,122 kg

Given the above load calculations I will use 6,122 kg as the compressive force max limit (based on the 10-XLPE material properties) as this is the lower of the bone compression strength, Oxinium implant strength, and 10-XLPE liner strength.

Next, let's add some tolerance to our chosen force capacities. I don't want to be lifting anywhere near the actual material maximum limits, so for safety, I'll halve these numbers respectively for the calculations I will use in the next stage:

**1,019****kg for shear**, which is half the force capacity of the acetabular cup implant when fully osteointegrated.

and**3,061 kg for compression**, which is half the force capacity of the 10-XLPE liner.

**Force Multipliers**

Next, we need to calculate the compression and shear force exerted on the hip when squatting and deadlifting. This will allow us to determine whether the forces generated inside the hip for any given weight lifted are within the above-chosen maximum force capacities.

**Deadlift Force Multipliers**

Though relating to forces on the spine, The Cholewicki et al. (1991) study on lumbar spine loads during heavy lifting found that the shear force multiplier for the conventional deadlift is approximately 4.2, meaning the lumbar spine experiences shear forces around 4.2 times the external weight lifted. For the sumo deadlift, this multiplier is slightly lower, at 3.9 due to the more upright posture. In terms of compressive forces, the multiplier is about 4.0 for both deadlift styles, with the sumo style resulting in marginally less compressive and shear stress on the spine. These findings provide useful estimates for understanding how lifting heavy weights can amplify internal forces, which can be applied cautiously to other joints like the hip.

Therefore, I will add a little tolerance to these ranges, and select a deadlift shear force multiplier of 3.8 - 5, and a compressive force of 4-5.

**Squat Force Multipliers**

Regarding the hip and spine during squats, studies indicate that squat depth significantly affects internal joint forces. Hartmann et al. (2013) found that deep squats can produce compressive forces up to 10 times body weight on the lumbar spine and between 6 to 10 times body weight on the hip joint due to increased hip flexion and muscle activation. Shear forces on the lumbar spine during deep squats range from 1.3 to 3.5 times body weight because of greater forward trunk lean, while shear forces on the hip joint are estimated between 1.0 to 2.0 times body weight.

As a powerlifter, I took pause at that. Deep squats have a larger force multiplier mainly due to higher forward trunk lean. Therefore, I'd expect that a low bar squat would similarly result in higher leverages compared to a high bar squat. So, in my training, I intend to consider a low bar squat akin to a deep squat, even if I limit the range of motion to hitting parallel.

What is also very interesting to learn is that, in contrast, shallow (partial) squats reduce these forces significantly. Compressive forces on the lumbar spine and hip joint decrease to approximately 4 to 6 times body weight, and shear forces on the lumbar spine lower to around 1.0 to 2.0 times body weight. Shear forces on the hip joint during shallow squats are minimal, often less than 1.0 times body weight.

Therefore, to ensure a conservative and safe approach, I will select a compressive force multiplier of 6 to 10 and a shear force multiplier of 2.0 to 3.5 for deep squats. For shallow squats, the compressive force multiplier can be adjusted to 4 to 6, and the shear force multiplier to 1.0 to 2.0. These multipliers account for individual variability and the increased forces associated with deeper squat depths.

Again, it makes sense why my surgeon advised me to avoid squatting below parallel in the early weeks of recovery given how much higher the shear and compression ratios are relative to a more shallow squat.

The Hartmann et al. (2013) study defines shallow squats as those with a knee flexion angle of 0° to 50°, and deep squats as those with 90° or greater knee flexion, affecting joint loading and muscle engagement.

**Summary of Chosen Force Multipliers**

In summary, here are the force multipliers I've chosen based on the above reasoning.

**Deep Squat Shear Force Multiplier:**

2 - 3.5**Deep Squat Compressive Force Multiplier:**

6 - 10**Shallow Squat Shear Force Multiplier:**

1 - 2**Shallow Squat Compressive Force Multiplier:**

4 - 6**Deadlift Shear Force Multiplier:**

3.8 - 5**Deadlift Compressive Force Multiplier:**

4 - 5

For clarity, a compressive force multiplier of 8 would mean that if I lifted 100kg and weighed 75kg, 175kg in total, then the force exerted on the hip for that movement would be a factor of 8 larger than this total weight, which in this example works out at 175kg x 8 = 1,400kg.

**Rate of Osteointegration**

The next critical piece of information we need to consider is the speed of osteointegration in the hip joint: Clearly, if the process of the implant fixing itself to the bone is only 25% complete, then it is not going to be able to take the full force it otherwise might be able to when the osteointegration process is complete. Given that I intend to return to powerlifting much sooner than the date of full osteointegration, I need to be able to model what I should be lifting at any given point post-surgery.

Osteointegration is unlikely to happen linearly. Biological processes often follow a logistic curve, meaning progress is initially slow, accelerates exponentially, and then reaches a phase of linear progression before tapering off towards the end. This pattern allows us to model the recovery period and estimate how quickly integration happens.

This pattern mirrors real-life dynamics, such as how cells divide, how tissues repair, or how populations grow, where growth initially lags, then accelerates when resources are abundant, and finally plateaus as limitations like nutrients, space, or biological feedback set in. Its ability to capture this S-shaped trajectory makes it ideal for modelling processes that involve constrained growth or saturation, providing a realistic and predictable framework.

Based on case studies, full osteointegration with the implant typically occurs by month nine. Armed with this knowledge and using the logistic curve, we can estimate the percentage of osteointegration at different points in time, which will help determine the percentage of force that can be applied through the joint, Which looks a little like this:

This logistics graph now models my estimates for the level of osteointegration each month: Around 10% in month two, 25% by month three, 50% in month four, and so on. This information is useful as I can apply these percentages to the theoretical maximum weight I can lift at full osteointegration to get an estimate of what the maximum I should be lifting is at each stage of recovery.

For example, I expect the maximum amount I can lift when the implant is only 50% osteointegrated is likely to be half of what I can lift when fully osteointegrated.

**How Much Can I Lift? Crunching the Numbers**

Now that we have all the force estimates for compression, shear, and osseointegration percentages at each given month, we can calculate the maximum force on one leg at each stage and, therefore, determine the maximum lift when using both legs.

As a reminder, once fully osseointegrated, we selected a maximum of 1,019 kg for shear, 17,839 for bone-implant compression, and 3,061 kg for 10-XLPE compression.

When lifting with two legs, the load is shared between them, effectively halving the weight borne by the operative hip. If one hip can take 1,019 kg of shear force, then the total shear force spread across two hips is double that at 2,038kg.

The table below shows us the maximum force distributed across both hips rather than the maximum individual lift at any given stage of osteointegration. Given that the 10-XLPE compression limit doesn't change with the level of osteointegration, I will multiply the bone-implant compression limit by the level of osteointegration first. Then, once this bone-implant compression strength surpasses the 3,061kg 10-XLPE compression limit, I will set that as the maximum compression force. This is why the max compression force starts low and rises, eventually sticking to the same number, whereas shear continues to scale.

*As I'll re-iterate later, my surgeon advice was not to lift anything remotely heavy in the first six weeks. So the weight limits should be ignored in favour of caution in these early weeks.*

You can see that. Initially, the forces tolerated by the hip are relatively low but increase significantly as osseointegration progresses, following a logistics curve. It's important to note that the table reflects only the forces within the hip joint, and we must apply the force multipliers to arrive at the lift limits.

Again, this is the maximum force at the hip joint, not the maximum permissible weight to lift, which will be lower based on the scale factors we introduced earlier. To determine the maximum weights that can be squatted or deadlifted at a given time, we need to apply the appropriate force multipliers—or rather, divide by them—to establish what weights correspond to the respective compression and shear limits.

By doing this, we can accurately calculate the maximum allowable lifting weight for each stage of my recovery.

To convert the maximum hip forces to weight lifted, let's take the osteointegration-adjusted force values from the above table and apply the relevant force multipliers for both compression and shear to determine the theoretical maximum weight that can be lifted at each stage. Remember that these values should account for both the weight lifted and my body weight.

For example, if a Deadlift has a maximum shear force multiplier of 3.8 - 5, and we know at month three the maximum allowable shear accounting for two legs is 509kg, the we can divide this number to arrive at the maximum weight liftable inclusive of bodyweight. So, in this example, we would see the following max permissible deadlift weights at month three:

- Upper range = 509kg / 3.8 = 134kg

(96kg after removing half my 74kg body weight) - Lower range = 509kg / 5 = 102kg

(65kg after removing half my 74kg body weight) - With the average being in the middle at 283kg

(116kg after removing half my 74kg body weight)

I've subtracted half my body weight rather than all of it because I figure approximately half my weight will be above the hip joint acting as load on that joint.

Based on the above calculation, we can see at month three that I should probably avoid deadlifting above 116kg based on the maximum permissible shear force (based on the averaged midpoint) or 65kg if I want to be risk-averse. There are some additional tolerances baked into this number for safety, so a little deviance probably won't hurt at month three, but you can see how this approach can guide my training.

Now, let's calculate this for all time periods and all compression and shear ranges, selecting the lower compression or shear to act as the allowable lift limit.

**For Shallow Squat:**

**For Deep Squat:**

*Notice how originally I thought the higher compression number meant that shear would be the limiting factor. Well, after we apply the multipliers, given these are so much higher for compression than sheer, these result in the compression limit being the main determining factor in most circumstances.*

**For Deadlift:**

Remember that although the table includes projections for upper, average, and lower weights, reflecting the minimum, average, and maximum ranges for the force multipliers discussed earlier; If I am fully risk-averse, I should make decisions based on the 'lower' value. But it's useful to know the full range regardless.

By incorporating these force multiplier ranges, we can calculate a range of maximum allowable lifting weights for each period, ensuring the weight load remains within the allowable compressive and shear limits for both body weight and external load. This will give us a clearer understanding of what the maximum limits should be for my lifting at different stages of recovery.

As discussed, we will pay attention to the last allowable lift range, which is the lower of the shear/compression limit for each respective month and lift, when guiding my training.

Lets now map these limits onto a graph so you can appreciate them visually:

**For Shallow Squat:**

**For Deep Squat:**

*These calculations and graphs are very rough estimates based on assumptions and variables that might be incorrect or ill-informed.*

**For Deadlift:**

*These calculations and graphs are very rough estimates based on assumptions and variables that might be incorrect or ill-informed.*

As I review these graphs, I can see why my surgeon was so cautious during the first six weeks of recovery; They were very clear that I should avoid weighted exercises beyond light accessory work on squats and deadlifts until that point. When I asked about more taxing movements, like squatting with a low-bar position, they advised waiting until three months. The graphs clearly show why.

For context the weights my maximum squat of 222 kilograms and my deadlift of 245 kilograms, and I'd often lift 70-50% of this in the gym when training. So you can see why, during the early stages of recovery—between one and three months—, typical gym lifts would be close to or even exceed the tolerance limits of the hip joint and implant, based on the osseointegration level at that time. Pushing those limits too soon could risk compromising the implant or delaying recovery.

However, things take off beyond month three or four, and the osseointegration has progressed to a point where the weights I typically lift are unlikely to affect the implant negatively despite full osseointegration not being complete until around month nine. By then, the joint can tolerate much more, making it safer to increase the load gradually without significant concern for the implant's integration.

**Considering Long Term Wear**

Of course, the risk of catastrophic failure isn’t the only factor to consider. In addition to how much load the joint can handle, the long-term health of my joint—and whether I may need revision surgery in the future—depends on wear. So, I also need to think about what repeatedly lifting heavy weights might mean for wear on the implant, and how that could affect its longevity.

Though not exactly the same material, similar materials to 10-XLPE have also undergone stress testing of 10Mpa for 1.5 million cycles in lab tests, this demonstrates that this material can handle high load forces for prolonged periods of time without failure or excessive wear. This is in addition to the research I mention in my recovery diary, showing how the Oxinium implants are tested with a force of 4000N (Around 400kg of force in the joint) for 45 million cycles with very minimal wear.

We also need to consider that the more we use the joint under heavy load—such as deadlifting every week—the increased wear on the 10-XLPE plastic is inevitable. This wear would be greater than if the joint were not subjected to such stress. Ultimately, this comes down to a personal decision about how much risk I’m willing to take in terms of the wear I’m exposing the joint to over time. I also need to weigh up the enjoyment and personal well-being I get from these activities.

While heavy lifting may increase wear, I’m mindful that by focusing on exercises like deadlifting and squatting, I’m avoiding highly repetitive activities like running, which also place significant force on the joint. However, it’s not clear from the literature whether heavy lifting or repetitive impact activities, such as running, are worse in terms of joint wear. This uncertainty underscores the importance of personal judgment.

In the coming weeks or months, I’ll need to reflect on these factors. Excessive wear on the plastic could result in the need for a revision surgery sooner than expected, compared with someone who isn’t placing such demands on the joint.

**A Word of Caution**

**Purpose of these calculations**

All the numbers I’ve compiled in this article were to answer a personal question: whether progressing to heavier weights posed a risk of dislodging the implant in my hip socket.

I wanted to assess the risk of catastrophic failure from lifting heavy, and identify when it would be safe to start increasing the load. However, it’s important to stress that I didn’t adjust my training based solely on these calculations. I also followed the advice of my surgeon and physiotherapist, and there was no chance I would ignore their recommendations just because I’d run some numbers. This analysis simply helped me visualise and understand my recovery better, enabling me to make more informed decisions.

I also reflecton the surgeon's advice not to lift anything heavy during the first six weeks of recovery. After the six-week mark, I was able to gradually resume lifting, and by the three-month point, the surgeon was far more encouraging about increasing the weight. Although we’ve modelled graphs predicting the potential load on the hip joint up to the first month, I'm now beyond that period. It was still correct for me to avoid weighted exercises or keep them to an absolute minimum at that time.

**Be risk adverse in the first six weeks (and don't add weight)**

Another concern during those initial six weeks is the risk of micro-movements in the joint. These can result from lifting, but also from everyday movements, especially anything involving torsion or twisting forces. These micro-movements can disrupt the osteointegration of the joint, which could have long-term consequences for its strength and stability.

It was definitely the right decision not to overdo it early on, and others should also be cautious, particularly in those critical first six weeks: **You should not have a don't have a "how far can I push the weight" mindset in these early weeks!**

**There Are Other Risks**

Please also bear in mind that the forced I've calculated here are based on a single lifting event, not many compounded over time. And though Wolff's law suggests that bone strength and recovery comes from mechanical stress, if we were to repeatedly lift at near 99% the load capacity of the bone-implant interface, this repetition at high load might increase the risk of catastrophic failure.

In addition, this article also doesn't cover other risks of lifting heavy, such as the impact of proper form on lift safety, muscle recovery around the incision, or risk of dislocation based on the nature, approach and risk of the movement you are doing. So, though understanding the load tolerance of the joint is useful, it's not the only factor to consider when deciding how to return to lifting safely. It's important to listen to your body and seek professional guidance.

Then, you also have the complex and hard-to-model risks of periprosthetic fracture (PFF), which I do not evaluate in this article. According to Nikolaos et al (2021)., Age, female gender, osteoporosis, and implant type (cementless implants have higher fracture risks) are notable factors increasing the likelihood of PPFs. The risk of getting one is also higher the closer you are when you have the surgery, and it reduces as osteointegration progresses. So though we can see the compressive forces of bone can be very high, there are many confounding factors which make this data point on its own unreliable.

**My Personal Reflection on These Risks**

Regarding how these additional risks influence my training choices: I am 36, male, with no signs of osteoporosis, and my surgery was over four months ago. I also believe my bones are likely stronger than average due to years of consistent powerlifting and maintaining a good diet (again, Wolff's Law). This further reduces my perceived risk. As a result, and reflecting on stories of other powerlifters returning to training after a hip replacement, I've decided that I’m prepared to take a measured risk and gradually return to lifting heavy weights in a controlled and cautious manner.

For me, this feels like the right balance of risk, though I understand that the risk isn’t zero. My surgeon advised that I could return to lifting, provided I avoid movements I cannot control well, and I plan to follow that advice. Ultimately, this is my personal judgment call and should not be taken as advice. As with the rest of this article, I simply want to share my thought process throughout this decision.

**Everyone's Journey is Different**

Remember that many factors can influence the speed of recovery and the accuracy of the numbers I’ve calculated. Different implant materials, your age, strength, the presence of micro-movements in the joint in early recovery (which can impact effective osteointegration), or conditions like osteoporosis can all affect how well the bone integrates with the implant. Your diet, nutrition, sleep, and overall health will also play a role in the success of osseointegration.

Given these variables and uncertainties, the information I’ve shared should be taken with extreme caution! I'm not a trained medical professional, this is not medical advice, this article is not a peer-reviewed medical study, and there is a good chance I've made mistakes in my reasoning.

These calculations are something I’ve done to help guide my own training safely, but it’s crucial to listen to your surgeon’s advice. They understand your specific situation and can provide tailored guidance that takes all these factors into account.

**Conclusion**

Getting back to powerlifting after a total hip replacement is a process that requires consideration of several factors, from the forces your implant can handle to the rate of osteointegration and the long-term impact on joint wear. Remember that while the calculations and estimations I’ve shared have helped guide my recovery, they’re only part of the picture.

I should also mention that my goal isn't to determine what I can achieve for a one-rep max. Realistically, I don’t plan on doing a one-rep max squat or deadlift again. The main reason is that I want to avoid putting my body under unnecessary stress and risking a technique failure, which could lead to a significant force multiple through the joint or, worse, torsion that could compromise the implant and lead to serious injury or dislocation.

In powerlifting, there's a concept called RPE (Rate of Perceived Exertion), which means lifting in a way that leaves some reps in reserve. For instance, an RPE 7 would leave three reps in the tank, while an RPE 8 would leave two. In practice, I don’t intend to go beyond an RPE 8, and most of my training will likely remain around RPE 7. This approach allows me to progress with the weights, considering the guidance from the graphs, while avoiding lifting too heavily to the point where my form breaks down. It’s a way to strike the right balance—progressing safely and getting enjoyment from lifting, without taking unnecessary risks.

Ultimately, the most important advice I can give is to work closely with your surgeon and physiotherapist, follow their recommendations, and take a gradual approach to increasing your load. The numbers might tell you what’s theoretically possible, but your body—and your medical team—will tell you what’s actually safe.

If you've found this article interesting, you may also enjoy my hip replacement recovery diary and three-month post-op Q&A. Also please get in contact if you have any feedback or improvements about this article.

If you'd like to play with my numbers, you can download the spreadsheet I created to calculate them and plot the graphs here.

**(I'm not a medical professional, and this is not medical advice! Please speak to a qualified medical professional to guide how you return to training post recover)**

**Key Takeaways:**

**Osteointegration is Key:**The early months of recovery focus on allowing the bone to integrate with the implant. This limits how much weight you can safely lift during the first stages.**Shear vs. Compression Forces:**Both shear and compression forces affect the hip joint. When calculating safe lifting limits, the lower of these two forces should guide your training progression.**Force Multipliers:**Exercises like squats and deadlifts create different stress levels on the hip joint, so using appropriate force multipliers helps calculate safe weight limits.**Listen to Your Surgeon and Physio:**While understanding the forces at play is important, always prioritise the guidance of your medical team. They know the specifics of your recovery better than any calculation.**Long-Term Wear Considerations:**It’s not just about short-term risks. Heavy lifting over time may increase wear on the implant, which could affect its longevity. Finding a balance between achieving your strength goals and preserving your joint health is essential.