Research Corner - Q&A Muscle Fatigue by Jason Anderson | Date Released : 23 Aug 2006 0 comments Print Close Question: I thought Jason Anderson’s recent Research Corner Q&A regarding Spot Reduction for Glutes was fantastic; however, there is one issue that confuses me. When we work a muscle, will other muscles take over, as in his example of fatiguing the legs, causing the glutes to handle the load during squatting comfortably and not respond by growing? Wouldn't the muscles working on their own like this cause them to grow? And where does this leave us in response to muscle activation such as stretching the adductors and working abductors before squatting or lunging? Answer: Many thanks for your feedback and your question. In the example of the “upright” squat, the angle of the femur and therefore the knee placement has moved further from our center of gravity, subsequently placing greater emphasis onto the quadriceps to control the increased forces at knee (work = force x distance). This is ever present in the deceleration of running or walking down steps. So the performance of this exercise, whether we have pre-exhausted the quadriceps or not, is as always dependant on the weakest link in the chain. We will only lose the ability to perform the task at hand due to fatigue in quads, while the glutes are still relatively fresh, which is why their adaptation will be far less than the response gained by the fatigued and therefore “stimulated” quads. The only way the glutes will take over and allow us to continue with the exercise is if we alter our position and bend forward more during the performance of the squat, something that is often seen at the end of a set of squats when the trainer is attempting to extend the set beyond the quads’ ability to overcome the same resistance. Furthermore, we can take a look at your example of stretching out the adductors to de-sensitize them, therefore reducing their force output and subsequently reducing their inhibition potential on the opposing abductors. This is a practice adopted by many fitness professionals to manipulate the neural drive, allowing us to maintain better knee control in the squat and lunge by facilitating a greater activation from the often suppressed and weaker lateral glutes. There is a big difference between pre-exhaust where we want to completely fatigue the muscle with an isolation exercise just before a compound one and pre-exercise facilitation where we only want to “awaken” a dormant muscle to get it a little more involved in the performance of a movement to maintain better control or positioning. So you could say that pre-exercise facilitation is about giving the muscle a “shake” and not completely annihilating it! I hope this is of some help. Back to top About the author: Jason Anderson Jason Anderson has dedicated his life to exercise development, with over 20 years of experience in the gym. Jason spent five years working for Premier Training International as Programme Manager for the Fitness Trainer Award and Advanced Personal Training qualifications. He was the inspiration behind Premier’s Personal Training Solutions department and the designer of their revolutionary WEB and flexibility training systems. Jason presents his concepts and principles at the top fitness conventions in the UK (Fitpro, Loughborough and Multitrax UK, Heathrow) and also at numerous club chains around the world. He is also a fitness expert, exercise model and regular contributor for Men’s Fitness and other industry publications. Jason specializes in postural correction, movement dysfunction, joint and back pain, injury rehabilitation and performance conditioning. He currently operates from the Amida Club in Hampton, Twickenham (FIA Fitness Club of the Year 2005), where he runs his successful personal training business and acts as PT Manager for One on One Fitness LTD. Full Author Details Related content Content from Jason Anderson Proper Form and Muscle Fatigue Gray Cook | Articles Spot Reduction for Glutes Jason Anderson | Articles Isolation to Integration Training? Part 1 Michol Dalcourt | Articles Hypertrophy Training Muscle Overuse Noah Hittner | Articles Isolation or Integration? James Crozier | Articles Pattern Overload - Part 1 Paul Chek | Articles Muscle Failure Lenny Parracino | Articles Compacted Spine Jason Anderson | Articles Muscle Fatigue Jason Anderson | Articles Leg Training Post Ankle Op Jason Anderson | Articles Proper Squat Technique Jason Anderson | Articles Spot Reduction for Glutes Jason Anderson | Articles Setting the Scapula During Lat Pull Downs Jason Anderson | Articles Breathing for Flexibility Jason Anderson | Articles Functional Bodybuilding Jason Anderson | Articles Please login to leave a comment Comments (0) Back to top