By Matthew Tuttle @DocTuttleDPT ,Steve Short @steveshortdpt ,and Paul Marshall @pwmmarshall

The National Basketball Association (NBA) is a high-intensity sport, with substantial challenges from the length and physical demands of the season, travel demands, time zone changes, irregular sleep patterns, and professional (i.e. media, sponsor) demands (table 1). Within this context there are challenges for decisions around the appropriate scheduling of recovery, training, injury prevention, and rehabilitation sessions. Physical qualities such as aerobic capacity, lower extremity strength and power, are important for modifying the performance, fatigue, and injury risk of NBA athletes. These qualities are developed in the off-season and maintained during the season for optimal athlete performance. This editorial aims to overview the primary challenges for scheduling exercise in the NBA season, and provide practical advice to assist practitioners in this environment.

NBA Load management

Load management is a controversial issue across elite sport, but is a primary consideration for game and training dose decisions. The lack of a ‘gold standard’ for internal (e.g. arbitrary units for game/session load, AUs) or external (e.g. distance covered, minutes played) load measures in any sport creates confusion and data inundation for NBA practitioners. Sports such as professional soccer and Australian Rules have identified a 48-72h window for recovery from competitive play, which leads to opportunities for in-season training sessions.This window cannot be applied to the more congested NBA schedule, with games often on back-to-back days or 4 games within 6 days. There is no definitive evidence for recommendations of NBA player recovery from games using internal or external load measures. Thus, informed choices about scheduling recovery and general conditioning sessions within the NBA season are difficult, and left to the decision-making systems within each team.

Pre- and in-season exercise scheduling

The progressively shortened NBA pre-season has created new challenges for practitioners. A spike in pre-season injuries has been observed at the ankle¹, hip and thigh². Whether this is explained by prescriptive error from coaches rapidly increasing training load from off-season levels, incorrect modality choice for stage of season, or another reason is unclear. Use of the acute-chronic load ratio (ACWR), as applied in other sports, may be utilized in the NBA for the transition from off- to pre-season. However, the practical challenge of off-season load monitoring leads to inaccuracies in a potential ACWR for the first several weeks of the season, which may misinform prescriptive decisions made for the athletes³. Moreover, confusion about the calculation and lack of research for numerous confounding variables (e.g. training and chronological age, injury history, cognitions) explains why the ACWR has not been agreed upon in any sport or successfully translated into the NBA^{4, 5}.

The difficulty of in-season resistance exercise prescription for the NBA athlete has been highlighted. Various measures of internal and external load were monitored for 48h after an NBA styled resistance exercise session⁶. While physical measures were recovered by 24h, self-rated fatigue required 48h.  This is concerning in the context of the NBA schedule, and would suggest full-body type resistance exercise sessions may not be appropriate in-season, and challenging to dose safely due to the imposing demands on the athletes.

Micro-dosing exercise

Dividing training sessions into smaller doses may mitigate the cost without compromising game-to-game recovery, while accumulating volume over the season. For example, the typical full-body strength session could be divided into the slow-speed movements (i.e. squats), with power-based exercises in a separate session or withheld to off-season (i.e. DB snatches, plyometrics).

Micro-dosing a minimally effective stimulus can facilitate prescription of calisthenic injury prevention exercises into warm-ups performed before on-court training (i.e. the morning shoot-around), similar to the use of Nordic hamstring exercise in professional soccer⁷. Indeed, the incidence of hamstring and adductor strain injuries in addition to the commonly reported ankle and knee injuries in NBA athletes, would suggest preventive measures are required. The frequency of games, and thus opportunity for exercise micro-doses, may alleviate the staleness and adherence issues reported in other sports for repetitive prescription⁸. Preventive exercises only need to be scheduled 1 to 2 times per week for effectiveness with as little as 1 working-set required for some athletes, thus allowing practitioners to micro-periodize different warm-up focuses from session to session (i.e. hamstrings, adductors, knee). The effective dose for any preventive exercise is unknown, and proposed minimal effective doses may be reliant on pre-season training.

Conclusion

At this time, basic objective assessments and ongoing subjective monitoring is likely the best avenue to determine readiness for in-season training and creates an opportunity to individualize, recommend, and implement various stimuli. Aside from standard recovery strategies such as best sleep and nutrition practice, properly navigating exercise dosage has the potential to improve athlete health and performance. Options such as micro-dosing exercise and programming focused on high risk areas may improve outcomes for the NBA athlete. However, without well-defined research and practice within the NBA, these measures remain individualized to the athlete and their respective teams.

Table 1. The demands of the NBA season.  Unless otherwise stated data are mean ± SD.

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Dr. Matthew Tuttle @DocTuttleDPT is the lead sports scientist and physical therapist for the Denver Nuggets of the National Basketball Association. He is currently based in Denver, CO, working and traveling with Denver Nuggets full time. Dr. Tuttle has previous experience working both clinically as well as in men’s and women’s professional soccer. His clinical focus is on the management of workload variations in the NBA and athlete care across the course of the season. Email: mct765@gmail.com

Dr. Steven Short @steveshortdpt is the Director of Sports Medicine for the Denver Nuggets of the National Basketball Association.  Dr. Short is board certified in Sports Physical Therapy, and is a Fellow of the American Academy of Orthopedic Manual Physical Therapists. Dr. Short is responsible for the integration of evidence-based musculoskeletal services throughout the organization’s high performance unit.

Dr. Paul Marshall @pwmmarshall is an Associate Professor in the School of Health Science at Western Sydney University, Australia.  Dr. Marshall has substantial clinical, research, and teaching experience focussing on the prescription of exercise to help people with chronic pain and disease, in addition to strategies to enhance sports injury prevention. Email: p.marshall@westernsydney.edu.au

References

1. Herzog MM, Mack CD, Dreyer NA, et al. Ankle sprains in the National Basketball Association, 2013-2014 through 2016-2017. Am J Sports Med 2019;47(11):2651-58.
2. Jackson TJ, Starkey C, McElhiney D, et al. Epidemiology of hip injuries in the National Basketball Association: a 24-year overview. Orthop J Sports Med 2013;1(3)
3. Drew MK, Cook J, Finch CF. Sports-related workload and injury risk: simply knowing the risks will not prevent injuries: Narrative review. Br J Sports Med 2016;50:1306-08.
4. Lolli L, Batterham AM, Hawkins R, et al. The acute-to-chronic workload ratio: an inaccurate scaling index for an unnecessary normalisation process? Br J Sports Med 2019;53:1510-12.
5. Windt J, Gabbett TJ. Is it all for naught? What does mathematical coupling mean for acute:chronic workload ratios? Br J Sports Med 2019;53:988-90.
6. Marshall PW, Metcalf E, Hagstrom AD, et al. Changes in fatigue are the same for trained men and women after resistance exercise. Med Sci Sports Exerc 2020;52(1):196-204.
7. van Dyk N, Behan FP, Whiteley R. Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes. Br J Sports Med 2019;53(21):1362-70.
8. Bahr R, Thorborg K, Ekstrand J. Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: the Nordic Hamstring survey. Br J Sports Med 2015;49(22):1466-71.