Buffering – A Method of Selecting Training Intensity
©Copywrite 2003 David Woodhouse
I contend that unless a lifter is testing a maximum a ‘buffer’ should always be employed between the training load and recent (repetition) maximum.
3 Repetition Maximum (RM) = 100k
3 reps at 95k
Buffer = 100 – 95 = 5k
As rep number decreases the magnitude of the buffer must increase since the load is closer to absolute maximum. I recommend the minimum buffer should be 10% for 1 – 4 reps and 5% for 5 – 8 reps. Larger buffers may be required as absolute strength increases since the higher the motor control (high fibre recruitment and rate coding, low Golgi and antagonistic inhibition) the greater central nervous system fatigue resulting from lifts near to maximum.
When loads approach maximum there is often a tendency to increase the speed of the eccentric phase and/or to over utilize cheat methods, e.g. flexing spine during the squat and lifting the hips during a bench press. Greater loads can then be lifted but greater muscle forces have likely not been achieved. By using a buffer technique remains (more) consistent and injury risk is substantially deceased.
The emotional requirement to lift at maximum means central nervous system stress is significantly greater than for a sub maximum effort. One possible exception is lifters who have learned to emotionally detach from his training and accept a performance decrement. A maximum effort generally precludes any further quality sets and may also detract from subsequent training sessions in the week. As a result volume may be reduced below the threshold required to generate (or sustain) an adaptation.
There is also research that suggests prolonged training in limit strength exercises (e.g. squat & bench) close to 1RM causes a decrease in speed (Rate of Force Development) that manifests before any decrement in the specific exercise. This is obviously important for power athletes such as sprinters and throwers. The Olympic lifts and their derivatives have a high speed component therefore any decrease in RFD will manifest itself immediately.
Lastly, an experienced lifter recognises that day-to-day variations in strength are quite significant. On a given day therefore a 90% lift can, in severe cases, actually represent a 100% effort. Percentages in any program must therefore only be a guide and the athlete should recognise this and have the discipline to decrease the load accordingly. In the future perhaps force plates will be widely used to calculate movement velocity. This would be useful to determine optimum training load and hence to avoid overtraining.
Drawing heavily from available strength literature, I illustrate below an example 4 week cycle; 3 sessions per week:
Wk 1: All 12% Buffer
Wk2: All 10% Buffer
Wk3: All 7% Buffer
Wk4: All 5% Buffer
For simplicity I like to translate percentages into loads, i.e. for a 1RM of 75 to 125k, 10% = 10k.; 1