The Fitness:Fatigue model (1982) suggests that as we train each rep, set and session, we accumulate fatigue and this in turn our performance will temporarily drop. As we recover and fatigue dissipates, fitness will then increase, as well as performance. 

When discussing recovery from sessions, it’s important to understand the different kinds of fatigue we may experience from different types of training and how they impact our ability to perform, especially if you are doing a combination of exercise types.

Peripheral Fatigue

• limb soreness, damage, swelling
• think high reps/volume
• Situations when you have little to no rest between sets/exercises.

Central Nervous System (CNS) Fatigue

• brain and spinal cord fatigue, loss of muscle excitation, rate of firing, inability to activate high threshold motor units
• think high or low reps, running etc
• Also situations when you have little to no rest between sets/exercises.

Anything involving conditioning “cardio” may generate more CNS fatigue as there is more total work done in the session with less rest throughout. If you brain is tired, your muscles won’t work as efficiently so without adequate recovery, you wouldn’t be able to perform in your next weights session to an optimum level. 

When it comes to training load for maximum strength and size gains, 10-15 sets/muscle group a week is the point of maximum yield for most of us. After this point, there will be a diminishing returns affect – you no longer receive the same progress or growth from the workout or exercise that you have been doing. That’s right, more is not always better.

To give you an idea of how these sets are preprogrammed into your training… In our Strength Space classes in the gym, you’re (on average) doing 5-7 sets on a muscle group/movement, with there being a combination of 3-4 main muscle groups being targeted each class. So this means that doing 2 x Strength Space classes a week would tick this box for strength and size gain on most major muscle groups/movements. Doing more than this isn’t shown to add any additional benefit. You would just be doing more training and getting little to nothing out of it. 

If you want to increase your squat, doing 2 sessions in a week with each session having ~5 sets in it (totalling 10 sets over the week) is ideal. Coming back for another session with more squats (or a movement that uses similar muscle groups ie. lunges) may not benefit you at all. The intensity at which you will perform this 3rd session may not be sufficient enough to improve your squat/leg strength further. You would just be doing another session for the sake of it. This can then have a flow on effect into the next week when you try that first session of the week again… on and on it goes until you’re just a sore, deflated zombie in the gym unable to work at the necessary intensity to see results. 

This isn’t to say don’t train hard, or with variety, it’s just a reminder to be aware of how your recovery (or lack of) is affecting your ability to perform in the gym, and by extension, train to reach your health and fitness goals.