Author(s): BROBAKKEN, M., SHERMAN, R., BERG, O.K., IZADI, M., TØIEN, T., UNHJEM, R.J., WANG, E., Institution: MOLDE UNIVERSITY COLLEGE, Country: NORWAY, Abstract-ID: 200

INTRODUCTION:
Lifelong strength training mitigates age-related decline in efferent neural drive. However, if this advantageous adaptation persists into very old age when muscle strength becomes critical for physical function and survival remains unknown.
METHODS:
Therefore, key neuromuscular strength determinants were compared following a decade in 6 male master athletes (MA; 81±3 yrs at follow-up) and 12 healthy older (OC; 82±5 yrs) controls.
RESULTS:
Octogenarian MA still exhibited superior leg press maximal strength (+28%, p<0.05) and rate of force development (RFD; +174%, p<0.01) than OC, albeit decreased (p<0.05-0.01) in both groups. Efferent neural drive, assessed by evoked recordings (m.soleus normalized V-waves; Vsup/Msup) during maximal contractions remained unchanged in both groups, extending a higher (+120%, p<0.05) value in MA than OC. Although peripheral motoneuron excitability (at 10% and maximal voluntary contraction [Hmax/Mmax; Hsup/Msup]) was not different between groups, OC experienced a decrease (-44%; -38%; p<0.05). Voluntary activation was not different between MA (89±4%) and OC (83±13%) and remained unaltered. Resting twitch (RT) peak force tended (+46%, p=0.062) to be greater in MA than OC. Other contractility measures were not different and attenuated similarly (RT RFD, -34-36%; rate of force relaxation, -54-60%; time-to-peak, +24%; time-to-relaxation, +44-82%; all p<0.05-0.01) in both groups. Notably, relatively large reductions in thigh cross-sectional area were observed in both groups (MA, 37%; OC, 38%; p<0.05).
CONCLUSION:
In conclusion, strength training benefits persist into very old age, counteracting age-related reductions in efferent neural drive in the presence of substantial muscle mass loss. This likely has great bearing on muscle strength, physical function, and quality of life.