The neuromechanics of ballistic lower limb resistance training contractions for the optimisation of power training guidelines

Neuromuscular power is the greatest predictor of mobility loss and fall risk in older adults. Therefore, maintaining muscle power is critical for healthy ageing. Current government resistance training (RT) guidelines recommend muscle strengthening using relatively heavy RT loads which appears to lack specificity for the development of muscle power. The aim of the current thesis was to investigate how concentric lifting intent, RT load, the inclusion of a prior eccentric lowering phase and the provision of velocity performance feedback affected older adult neuromuscular performance and perceptual responses during acute resistance exercise. Power performance was related to both the explosive and ballistic intent during the concentric lifting phase, i.e. fast ballistic [FAST-B] > fast non-ballistic [FAST-NB] > conventional [CONV]. FAST-B contractions produced 49 to 1172% greater mean power performance than CONV and FAST-B contractions, underpinned by greater mean and peak force (+10 - 136%) and velocity (+40 to 483%), and greater knee extensor activation (KEEMG) across RT loads. The inclusion of a prior eccentric lowering phase (ECC-CON) produced a load dependent greater performance in mean power, +15% at 35%1RM rising to +38% at 80%1RM, than concentric contractions performed from rest (CON-Only). The provision of velocity performance feedback (VEL-FB) did not augment power production with the optimal load (35%1RM) during FAST-B RT. However, when asked about their anticipated adherence 92% of older adults preferred velocity feedback over no feedback. Comparison of RT sessions (FAST-B with the optimal load for power production (35%1RM) vs CONV with a high load (80%1RM) revealed greater power (+308%), velocity (+489%), KEEMG (+50%) and a preference for anticipated adherence with FAST-B RT. Finally, a pilot study found that the changes in neuromuscular performance following 5-weeks of RT with either FAST-B (35%1RM) or CONV (80%1RM) appeared to be specific to the type of RT performed, such that CONV produced noteworthy improvements in maximum strength (i.e. one repetition maximum, isometric strength), while FAST-B RT produced noteworthy improvements in power and velocity. In conclusion, it appears that fast and ballistic RT may offer a more potent power development stimulus for older adults than commonly recommended convention RT. However, more research is needed to establish the efficacy and effectiveness of FAST-B RT for improving the muscle function of older adult.