Aging increases metabolic capacity and reduces work efficiency during handgrip exercise in males

Maximal oxygen uptake and exercise performance typically decline with age. However, there are indications of preserved vascular function and blood flow regulation during arm exercise. Yet, it is unknown if this potential physiological preservation with age is mirrored in peripheral metabolic capacity and V̇O2/watt ratio. Thus, to investigate the effects of aging in the arms, we measured metabolic and vascular responses to 6-minute bouts of dynamic handgrip exercise at 40% and 80% of maximal work rate (WRmax) in eleven young (26±2yr) and twelve old (80±6yr) males, applying Doppler-ultrasound combined with blood samples from a deep forearm vein. At baseline, old had a larger arterial diameter compared to young (p<0.001). During exercise, the two groups reached the same WRmax. V̇O2, blood flow, and oxygen supply were higher (40%WRmax; 80%WRmax, all p<0.01), and arterio-venous oxygen-difference lower (80%WRmax, p<0.02), in old compared to young. Old also had a higher oxygen-excess at 80%WRmax (p<0.01) than young, while no difference in muscle diffusion or oxygen-extraction was detected. Only young exhibited an increase in intensity-induced arterial dilation (p<0.05), and they had a lower mean arterial pressure than old at 80%WRmax (p<0.001). V̇O2/watt (40%WRmax; 80%WRmax) was reduced in old compared to young (both p<0.05). In conclusion, in old and young males with a similar handgrip WRmax, old had a higher V̇O2 during 80%WRmax intensity, achieved by an increased blood flow. This may be a result of the available cardiac output reserve, compensating for reduced work efficiency and attenuated vascular response observed in old

Maximal strength training-induced increase in efferent neural drive is not reflected in relative protein expression of SERCA.

Funder: Norges Teknisk-Naturvitenskapelige Universitet; doi: http://dx.doi.org/10.13039/100009123Funder: Molde University CollegeFunder: Molde University College - Specialized University in LogisticsINTRODUCTION: Maximal strength training (MST), performed with heavy loads (~ 90% of one repetition maximum; 1RM) and few repetitions, yields large improvements in efferent neural drive, skeletal muscle force production, and skeletal muscle efficiency. However, it is elusive whether neural adaptations following such high intensity strength training may be accompanied by alterations in energy-demanding muscular factors. METHODS: Sixteen healthy young males (24 ± 4 years) were randomized to MST 3 times per week for 8 weeks (n = 8), or a control group (CG; n = 8). Measurements included 1RM and rate of force development (RFD), and evoked potentials recordings (V-wave and H-reflex normalized to M-wave (M) in the soleus muscle) applied to assess efferent neural drive to maximally contracting skeletal muscle. Biopsies were obtained from vastus lateralis and analyzed by western blots and real-time PCR to investigate the relative protein expression and mRNA expression of Sarcoplasmic Reticulum Ca2+ ATPase (SERCA) 1 and SERCA2. RESULTS: Significant improvements in 1RM (17 ± 9%; p < 0.001) and early (0-100 ms), late (0-200 ms) and maximal RFD (31-53%; p < 0.01) were observed after MST, accompanied by increased maximal Vmax/Msup-ratio (9 ± 14%; p = 0.046), with no change in H-reflex to M-wave ratio. No changes were observed in the CG. No pre- to post-training differences were found in mRNA or protein expressions of SERCA1 and SERCA2 in either group. CONCLUSION: MST increased efferent neural drive to maximally contracting skeletal muscle, causing improved force production. No change was observed in SERCA expression, indicating that responses to high intensity strength training may predominantly be governed by neural adaptations

Maximal strength training improves strength performance in grapplers

The aim of this study was to assess the short-term effects of maximal strength training (MST) as an accessory to grappling training on strength performance in competitive Brazilian Jiu-Jitsu (BJJ) athletes. Fourteen male BJJ athletes underwent measurements of 1 repetition maximum (1RM) in the squat and bench press, rate of force development (RFD) and peak force (PF) in the squat jump, countermovement jump (CMJ) height, and muscular endurance in pull-ups, sit-ups, and push-ups. After baseline measurements, subjects were randomly allocated to either an MST group or control group (CON). The MST intervention consisted of 4 × 4 repetitions at ≥ 85% of 1RM in the squat and bench press, and 4 sets of pull-ups to failure, performed 3× per week. Both groups were instructed to maintain their BJJ training and avoid additional strength training. Maximal strength training improved 1RM in the squat and bench press by 15 ± 9% (p = 0.02) and 11 ± 3% (p = 0.03), respectively, and CMJ height by 9 ± 7% (p = 0.04). Muscular endurance performance increased by 33 ± 33% in pull-ups (p = 0.03), 32 ± 12% in push-ups (p = 0.03), and 13 ± 13% in sit-ups (p = 0.03). Increases in RFD (35 ± 55%, p = 0.13) and PF (8 ± 9%, p = 0.09) did not reach significance. No improvements were apparent from BJJ training alone (p > 0.05). These findings suggest that MST is a potent approach to rapid improvements in maximal strength, power, and muscular endurance in active grapplers