This blogpost is based on Brad Schoenfeld presentation on how to maximise hypertrophy post ACLR at the Aspetar ACL Conference
Introduction
It’s uncommon for many athletes to have deficits in maximal strength, rate of force development (RFD), and reactive strength following anterior cruciate ligament reconstruction (ACL)
It’s believed that the benefits of strength training and muscular conditioning for athletes during their rehabilitation not only speed up recovery time, but also reduces the risk of future injuries and their residual effects on athletic performance.
This blogpost is based on Brad Schoenfeld presentation at the Aspetar ACL Conference #aspetarACL2023 where he presented on how to maximise hypertrophy post ACLR.
Rehab Must Follow Proper Progression
A study Anterior Cruciate Ligament Tear: bridging the gap between research and practiced led by the University of Delaware conducted a checklist table for suggested progression for return to competition:
The Position Stand
To achieve the goal of return to competition the IUSCA has published a position stand of leading experts in the field of Resistance Training and provided recommendations to maximize muscle hypertrophy in an athletic population The recommendations represent a consensus of a consortium of experts in the field, based on the best available current evidence.
According to Brad Schoenfeld Hypertrophy can be operationally defined as an increase in axial cross-sectional area of a muscle fiber or whole muscle due to increase in size of pre-existing muscle fibers and not to increase muscle fibers numbers. Several contributor are included in the process such as a shift in muscle net protein balance favoring new net protein accretion as well as satellite cell content and activation.
For some athletes, muscular bulk and, conceivably, the accompanying increase in strength/power, are desirable attributes for optimal performance. In some cases, even relatively small improvements in hypertrophy might be the difference between winning and losing in competition for these athletes.
To increase hypertrophy there are many training variables that can be manipulated. Let go through some of the those variables as Brad Schoenfeld presented.
Concurrent Training
Current evidence does not seem to support a concurrent training ‘interference’ effect for hypertrophy at least within the relatively moderate volumes studied.
Assuming that training volumes are not overly excessive and trainees can likely engage in aerobic/endurance type (cardio) training alongside their resistance training without detriment to their adaptive response.
Given the relative uncertainty of evidence on the topic, it would seem prudent to schedule aerobic and resistance bouts at least several hours apart or, perhaps even better, perform them on separate days to minimize any potential detrimental effects on hypertrophy. If this is infeasible, then best to perform resistance training before cardio.
Set-End Point
Novice lifters can achieve robust gains in muscle mass without training in proximity to failure; the need to increase the intensity of effort appears to become increasingly important as one becomes well-trained.
Highly trained lifters may benefit from taking some sets to momentary muscular failure. The end set should be employed somewhat conservatively (limit to the last set of a given exercise).
Confining the use of failure training primarily to single-joint movements and machine-based exercises may help to manage the stimulus-fatigue ratio and thus reduce potential negative consequences on recovery.
Older athletes should employ failure training more sparingly to allow for adequate recovery.
Periodizing failure training may be a viable option: very high levels of effort are employed liberally before a peaking phase and then followed by a tapering phase involving reduced levels of effort.
Exercise Selection
Hypertrophy-oriented resistance training programs should include a variety of exercises that work muscles in different planes and angles of pull to ensure complete stimulation of the musculature. Programming should employ a combination of multi- and single-joint exercises to maximize whole muscle development; where applicable, employ exercises that work muscles at long lengths.
Free-weight exercises with complex movement patterns should be performed regularly to reinforce motor skills; less complex exercises can be rotated more liberally for variety. Attention must be given to applied anatomical and biomechanical considerations so that exercise selection is not simply a collection of diverse exercises, but rather a cohesive, integrated strategy designed to target the entire musculature.
Frequency
Significant hypertrophy can be achieved when training a muscle group as infrequently as once per week in lower- to moderate-volume protocols.
There does not seem to be a hypertrophic benefit to greater weekly per-muscle training frequencies provided the set volume is equated.
It may be advantageous to spread out volume over more frequent sessions when performing higher-volume programs.
A general recommendation for frequency: Cap per-session volume at ~10 sets per muscle and increase weekly frequency to distribute additional volume if/when applicable.
Volume
A dose of approximately 10 sets per muscle per week would seem to be a general minimum prescription to optimize hypertrophy. Some individuals may demonstrate a substantial hypertrophic response on somewhat lower volumes.
Evidence indicates potential hypertrophic benefits to higher volumes, which may be of particular relevance to underdeveloped muscle groups. There may be a benefit to periodizing volume to increase systematically over a training cycle.
Load
Comparable muscle hypertrophy can be achieved across a wide spectrum of loading zones.
Early post-rehab may be beneficial to employ higher repetition schemes (≥ 15). Thereafter, may be a practical benefit to prioritize the use of moderate loads for the majority of sets in a hypertrophy-oriented training program.
Preliminary evidence suggests a potential hypertrophic benefit to employing a combination of loading ranges. This can be accomplished through a variety of approaches including:
- Varying repetition ranges within a session from set to set
- Implementing periodization strategies with specific ‘blocks’ devoted to training across different loading schemes
Planning/Periodization
There is no clear consensus on whether or how training for hypertrophy should be periodized. It sounds logical basis to employ some form of planning/periodization for hypertrophy training.
The specific organization for manipulating variables can be achieved in many different ways There is no universal “best” method for planning; specific to the given athlete and his/her sport.
Advanced Training Techniques
The present body of literature does not empirically support the use of advanced training methods for enhancing hypertrophic adaptations:
Eccentric overload has the most evidentiary support and thus may be selectively implemented as a novel stimulus.
Other advanced methods (drop-set, pre-exhaustion, and superset training) are lacking evidence for a beneficial hypertrophic effect but do not show detrimental effects.
- Drop-set and superset training might provide a more time-efficient approach to increasing muscle hypertrophy compared to traditional training
- Pre-exhaustion training may present health and safety benefits over a training career; fatiguing a target muscle with a single joint movement might serve to decrease the necessary load for the ensuing multi-joint movement and thus reduce the subsequent forces around anatomical joints.
Conclusion
To summarize the presentation from Brad Schoenfeld on strength and hypertrophy in rehabilitation. There are various variables when it comes to maximizing hypertrophy variables like exercise selection, set-end points, frequency, volume, and load adjustments.
Reference
Arias, Roberto1; Monaco, Jerry2; Schoenfeld, Brad J.1. Return to Sport After an Anterior Cruciate Ligament Tear: Bridging the Gap Between Research and Practice. Strength and Conditioning Journal ():10.1519/SSC.0000000000000774, March 16, 2023. | DOI: 10.1519/SSC.0000000000000774
Schoenfeld, B., Fisher, J., Grgic, J., Haun, C., Helms, E., Phillips, S., Steele, J., & Vigotsky, A. (2021). Resistance Training Recommendations to Maximize Muscle Hypertrophy in an Athletic Population: Position Stand of the IUSCA. International Journal of Strength and Conditioning, 1(1). https://doi.org/10.47206/ijsc.v1i1.81
