Power Training in Older Adults: From Neurophysiology / Neuromechanics to Daily Live

• Applicant: Dr. Christoph Mickel
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology ; Anatomy and Physiology ; Biogerontology and Geriatric Medicine ; Molecular Biology and Physiology of Neurons and Glial Cells
• Term: from 2017 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 345340115

The incidence of falls per year in the population aged 65 years and older is around 35% and increases for persons older than 80 years to more than 50%. Around 80% of those falls could result from intrinsic factors related to the age-related loss of motor function due to a loss of motor units, changes in fibre type compositions, reduced neuromuscular activation, and a slowed rate of muscle activation. An active life style including physical exercises can partly counteract the age-related alterations of the neuromuscular system. From a functional point of view, a positive correlation between maximal strength respectively rate of force development and postural control exists. However, neither the optimal combination of exercise volume and intensity nor the underlying neurophysiological mechanisms of the concurrent training regimen have been revealed in the elderly. Experimental studies with young adults have shown that strength training with higher loads increases maximal force production and thereby rate of force development, whereas strength training with smaller loads and maximal movement velocity only increases rate of force development. The underlying physiological effects and if elderly persons organisms respond in the same way has not been fully documented and is the main purpose of this project. The following research design can yield a substantial amount of useful knowledge in this context: 30 adults (> 65 years, genders divided equally), who will be split into two intervention groups through parallelization (criteria will be gender and maximal force production), will exercise their dorsiflexor muscles for a period of 12 weeks at a frequency of three sessions per week. One group (Tpower) will perform a power training program with 5 sets of 8 repetitions at an intensity of 30% to 40% of their individual one repetition maximum (1RM) and 3 minutes of rest between the sets, whereas the second group (Tstrength) will perform a training program with 6 sets of 6 repetitions at an intensity of 80% of 1RM and 3 minutes of rest between the sets. By means of biomechanical measurements the exercise-induced adaptations will be captured and neurophysiological techniques will reveal the underlying mechanisms. The electrophysiological characteristics of single motor units of tibialis anterior will be determined via fine-wire electrodes. Further, surface-electromyographic data of tibialis anterior, soleus, and gastrocnemius medialis will be determined and the resultant torque will be identified using force transducers.

• DFG Programme: Research Fellowships
• International Connection: Belgium
• Host: Professor Dr. Jacques Duchateau