📚 Upside Studies: Impact of Achilles Tendon Ruptures in the NBA / The Influence of NBA Crowds on Effort & Home Advantage / Female Athletes Study
Overview
Achilles tendon ruptures are among the most severe injuries that NBA players can sustain, often impacting their ability to return to play (RTP) and maintain pre-injury performance levels. This study analyzes the economic burden and performance consequences of Achilles tendon ruptures in the NBA between 1990 and 2023, focusing on the cost of recovery (COR) for franchises, as well as pre- and post-injury player success metrics. The findings provide critical insights into financial losses, career longevity, and statistical performance following an Achilles injury.
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Study - Key Findings
1. Return to Play (RTP) and Career Longevity
The overall RTP rate was 78.38%, meaning that roughly 22% of players never returned to an NBA game after sustaining an Achilles tendon rupture.
Among those who returned, only 27.03% were able to reach their previous level of success.
The NBA career retention rate three years post-injury was 54.05%, indicating that nearly half of the affected players were out of the league within three years of returning.
Reserve players had the highest RTP rates but were often used less frequently post-injury.
All-Star players saw the greatest decline in playing time, despite being the most productive pre-injury.
2. Economic Impact on NBA Teams
The average cost of recovery (COR) per player was estimated at $4 million, which includes salary payments for games missed.
The total financial loss from Achilles tendon ruptures in the NBA between 1992 and 2019 was $117.58 million.
All-Star players had the highest COR at $5.7 million per player, followed by Starters ($3.4 million) and Reserves ($3 million).
Players with higher pre-injury salaries had greater financial impact on teams, but higher salaries did not guarantee a better post-injury career.
3. Performance Decline Post-Injury
Total minutes played and statistical performance metrics significantly declined across all groups.
All-Star players saw the biggest drop-off, losing an average of 18,838 total minutes played post-injury.
Starters had the lowest return-to-peak-performance rate (0%), while Reserve players had a 100% return rate.
Players' player efficiency rating (PER) dropped substantially, but there were no significant differences among groups in post-injury PER.
Win Shares per 48 Minutes (WS48) and Value Over Replacement Player (VORP) also declined across all groups, reflecting a general reduction in productivity.
4. Salary Trends and Financial Outcomes
Higher-paid players (Group C: >$8.9 million per year) had the greatest COR but did not show a statistically significant advantage in career success post-injury.
Pre-injury high-salary players had more playing time before injury, but their minutes played per game dropped significantly afterward.
Surprisingly, players in the lowest salary group (Group A: <$3.9 million per year) saw their salaries increase post-injury, whereas high-earning players saw consistent salary declines after their Achilles rupture.
Despite declining performance, All-Star and high-salary players still received more playing time than lower-tier players after returning.
5. Comparison to Other NBA Injuries
Achilles tendon ruptures are financially more costly than ACL tears, with an average COR of $4 million per player compared to $2.9 million per player for ACL injuries.
NBA teams are more financially impacted by Achilles injuries than other orthopedic injuries, primarily due to long recovery times and contract guarantees.
The Achilles rupture RTP rate (78.38%) is lower than RTP rates for other NBA injuries such as ankle fractures or ACL tears.
The study highlights the need for enhanced injury prevention and rehabilitation protocols to reduce both economic and performance losses.
Implications for NBA Franchises and Future Considerations
This study provides valuable insights for NBA teams, medical staff, and league executives regarding the long-term consequences of Achilles tendon ruptures. Given the high financial cost and steep decline in player performance, franchises must consider better injury prevention strategies, such as:
Enhanced Load Management: Reducing excessive strain on players to prevent overuse injuries.
Investment in Recovery Protocols: Advanced rehabilitation methods, including biomechanics assessments, physiotherapy innovations, and surgical advancements, to improve RTP outcomes.
Contract Structuring: Given the high financial burden of guaranteed contracts, teams may explore performance-based incentives rather than fixed salary structures for high-risk players.
Technology & Wearables: Utilizing player tracking, biomechanics analysis, and AI-driven injury prediction tools to identify risk factors before an Achilles rupture occurs.
Conclusion
Achilles tendon ruptures are among the most devastating injuries in the NBA, impacting both player performance and team finances. While most players return to play, very few regain their pre-injury form, particularly high-level players like All-Stars and Starters. The study underscores the need for improved rehabilitation protocols and financial planning by NBA franchises to mitigate the long-term impact of Achilles injuries.
Upside Study: Home is Where the Hustle Is: The Influence of Crowds on Effort and Home Advantage in the NBA
This study examines the impact of home crowds on player effort and home advantage in the NBA, leveraging the natural experiment provided by the COVID-19 pandemic. During the 2020-2021 NBA regular season, 53.4% of games were played without spectators, allowing researchers to isolate the crowd effect from other factors like travel and location familiarity. Using statistical analysis, the study finds that home advantage is significantly influenced by the presence of fans, with crowd-driven effort—particularly in rebounding—being the primary factor.
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Study - Key Findings
1. The Presence of Crowds Significantly Boosts Home Advantage
In games with crowds, home teams won 58.65% of the time. In games without crowds, the home win rate dropped to 50.60%—essentially eliminating home advantage.
Home teams outscored their opponents by an average of 2.2 points per game with fans present, whereas there was no scoring advantage (−0.13 points differential) in games without fans.
This equates to a 15.91% increase in win percentage when playing in front of home fans, a difference that could affect playoff seeding and championship runs.
2. Rebounding Effort is the Main Driver of Home Advantage
Home teams grabbed 2.3 more rebounds per game in front of fans than in empty arenas.
The effect was present for both offensive (+1.1) and defensive rebounds (+1.6), highlighting that crowd support influenced hustle plays.
Rebounding differential fully explained the home scoring advantage, meaning the boost in effort from home teams directly translated into more points and wins.
3. No Evidence of Referee Bias or Away Team Distraction
Unlike previous studies suggesting that referees favor home teams due to crowd influence, this study found no significant difference in foul calls between home and away teams.
Crowd presence also did not impact free throw shooting accuracy, debunking the idea that loud or hostile fans distract opponents at the free-throw line.
Other shooting metrics (field goal percentage, three-point percentage, and effective field goal percentage) were also unaffected by the presence of a crowd.
4. Crowd Size and Density Do Not Matter Beyond Presence
While the presence of any crowd boosted home performance, the number of fans (crowd size) and how full the arena was (crowd density) had no significant additional effect.
This suggests that the psychological and motivational benefits of a home crowd are not necessarily stronger with more fans, but rather simply having any crowd is enough to make a difference.
Implications for the NBA and Teams
Competitive Balance and Playoff Seeding
A 15.91% increase in home win percentage due to fan presence is equivalent to shifting from a low playoff seed (e.g., 10th place in the conference) to a high seed (e.g., 5th place).
Higher playoff seeds are rewarded with more home games, reinforcing the advantage of securing a top seed in the regular season.
Coaching and Player Strategies
Since home teams increase effort-based plays like rebounding in front of crowds, coaches may emphasize hustle statistics like rebounding, loose ball recoveries, and defensive intensity during road games to counteract this effect.
Teams that struggle on the road might benefit from mental training or simulations designed to replicate high-energy environments to close the home-road effort gap.
Potential League Adjustments
The NBA could explore ticketing policies that increase away team fan presence to reduce extreme home-crowd biases and promote more balanced competition.
The study raises questions about whether neutral-site games (such as in-season tournaments or playoffs at neutral venues) would eliminate home advantage and make outcomes more predictable.
Conclusion
This study provides strong evidence that the primary driver of home advantage in the NBA is the presence of fans and their effect on player effort, particularly in rebounding. Contrary to previous research, referee bias and opponent distraction were not significant factors. The findings have major implications for competitive balance, coaching strategies, and potential league rule changes.
Upside Study: Monitoring Training Load and Wellness of Female Footballers Transitioning Between Club and National Teams
Introduction
The transition between club and national team (NT) duties presents unique challenges for elite female footballers. With limited preparation time before major international tournaments, players must quickly adapt to different training loads, coaching strategies, and recovery protocols. This study investigates how these transitions impact training volume, match exposure, internal load (session rating of perceived exertion or s-RPE), and perceived wellness.
The research focuses on 42 professional female footballers selected for the Australian national team across seven international tournaments from 2019 to 2021. It examines two transition phases:
Entering NT duties (Club to NT) – The two weeks before and first week with the NT.
Returning to club play (NT to Club) – The final week with the NT and the two weeks after returning to clubs.
By tracking session counts, s-RPE, and wellness indicators (fatigue, muscle soreness, sleep, and stress), the study aims to provide practical insights for optimizing training load management and recovery strategies in elite women’s football.
You can download the full PDF study by clicking on the button below:
Study - Key Findings & Insights
1. Increased Training Load but Decreased Match Load Upon Entering NT Duties
Training session count increased significantly when players transitioned from club to NT play (p < 0.0001, ES > 0.67).
Match count dropped during this period (p < 0.05, ES < -0.34), as national teams emphasized training over match play in preparation for tournaments.
Training s-RPE (perceived training intensity) increased moderately (p = 0.012, ES = 0.35), reflecting higher training demands in NT camps compared to club settings.
Despite increased training exposure, total s-RPE did not change significantly, suggesting clubs may already be managing workloads to align with NT demands.
2. Reduced Workload and Match Exposure Upon Returning to Club Teams
After NT duties, training and total session counts dropped significantly when players returned to club play (p < 0.0001, ES < -0.86).
Match exposure decreased further in the first week back at the club (p < 0.0001, ES < -1.4), likely as clubs prioritized rest and recovery for returning players.
While training session count was lower, training s-RPE remained stable, suggesting clubs maintained training intensity despite reducing session frequency.
Match s-RPE significantly decreased, indicating that club matches post-NT were less demanding than those played with the national team.
3. Perceived Wellness Remained Unchanged Despite Fluctuating Workloads
No significant changes were observed in perceived wellness (fatigue, muscle soreness, sleep, or stress) across all transitions (p > 0.05, ES between -0.34 and 0.35).
This suggests that players generally adapted well to workload fluctuations or that self-reported wellness measures may not be sensitive enough to detect subtle stressors.
Previous studies have shown that match outcomes influence perceived wellness, with wins improving fatigue and stress scores, which could explain the stability in wellness scores despite higher training loads.
The study highlights the need for more granular monitoring methods, such as daily tracking instead of weekly averages, to better capture fluctuations in player well-being.
Practical Implications for Performance, Coaching, and Sports Science
1. Enhancing Load Management & Injury Prevention Strategies
The clear differences in training volume and match exposure between club and NT play demonstrate the importance of load monitoring.
Rapid increases in training loads upon entering NT camps could increase injury risk, emphasizing the need for progressive adaptation strategies.
National teams and clubs should collaborate on player workload data-sharing, ensuring a smoother transition and reducing injury risks due to mismatched training loads.
Strength and conditioning coaches should use simple load metrics like session count and s-RPE, which can provide effective insights when GPS or heart rate data are unavailable.
2. Adjusting Training and Recovery After International Tournaments
Since NT training involves higher training but lower match exposure, clubs may need to gradually reintegrate players into match intensity rather than immediately reducing training volume.
Players returning from NT duty should not be over-rested—gradual reintroduction to full club schedules ensures performance maintenance and injury risk reduction.
Club coaching staff should tailor individual recovery plans based on NT workloads, rather than using a one-size-fits-all approach.
3. Refining Wellness Monitoring Systems for Better Athlete Insights
Despite significant fluctuations in training load, perceived wellness remained unchanged, raising concerns about its effectiveness in capturing player readiness.
Wellness tracking should be more frequent (daily instead of weekly) to detect short-term fluctuations and better inform recovery strategies.
Clubs and NTs could explore biometric monitoring tools (such as heart rate variability or sleep tracking wearables) to complement subjective wellness reports.
Conclusion: Optimizing Player Transitions Between Club and National Teams
This study provides the first comprehensive analysis of training loads and wellness in elite female footballers transitioning between club and national team duties. Key findings highlight:
Increased training loads and reduced match exposure when players transition into NT camps.
Significantly reduced training and match loads upon returning to clubs, potentially due to recovery prioritization and rotation policies.
Stable perceived wellness despite workload fluctuations, suggesting that players generally adapt well or that current wellness monitoring lacks sensitivity.
These insights emphasize the importance of collaboration between club and national team staff to ensure smooth transitions and optimized player health, recovery, and performance. By refining load monitoring strategies, enhancing recovery protocols, and improving wellness tracking, stakeholders can better manage elite female footballers' workloads and well-being throughout the season.
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