Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women.

Aging-associated inflammation is characterized by senescent cell-mediated secretion of high levels of inflammatory mediators, such as microRNA (miR)-146a. Moreover, a rise of circulating cell-free DNA (cfDNA) is also related to systemic inflammation and frailty in the elderly. Exosome-mediated cell-to-cell communication is fundamental in cellular senescence and aging. The plasma changes in exercise-promoted miR-146a-5p, cfDNA, and exosome release could be the key to facilitate intercellular communication and systemic adaptations to exercise in aging. Thirty-eight elderly subjects (28 trained and 10 controls) volunteered in an 8-week resistance training protocol. The levels of plasma miR-146a-5p, cfDNA, and exosome markers (CD9, CD14, CD63, CD81, Flotillin [Flot]-1, and VDAC1) were measured prior to and following training. Results showed no changes in plasma miR-146a-5p and cfDNA levels with training. The levels of exosome markers (Flot-1, CD9, and CD81) as well as exosome-carried proteins (CD14 and VDAC1) remained unchanged, whereas an attenuated CD63 response was found in the trained group compared to the controls. These findings might partially support the anti-inflammatory effect of resistance training in the elderly as evidenced by the diminishment of exosome CD63 protein expression, without modification of plasma miR-146a-5p and cfDNA.

Aerobic training (AT) can support brain health in Alzheimer’s disease (AD); however, the role of resistance training (RT) in AD is not well established. Aside from direct effects on the brain, exercise may also regulate brain function through secretion of muscle-derived myokines. Aims. This study examined the effects of AT and RT on hippocampal BDNF and IGF-1 signaling, β-amyloid expression, and myokine cathepsin B in the triple transgenic (3xTg-AD) model of AD. 3xTg-AD mice were assigned to one of the following groups: sedentary (Tg), aerobic trained (Tg+AT, 9 wks treadmill running), or resistance trained (Tg+RT, 9 wks weighted ladder climbing) (n=10/group). Rotarod latency and strength were assessed pre- and posttraining. Hippocampus and skeletal muscle were collected after training and analyzed by high-resolution respirometry, ELISA, and immunoblotting. Tg+RT showed greater grip strength than Tg and Tg+AT at posttraining (p<0.01). Only Tg+AT improved rotarod peak latency (p<0.01). Hippocampal IGF-1 concentration was ~15% greater in Tg+AT and Tg+RT compared to Tg (p<0.05); however, downstream signals of p-IGF-1R, p-Akt, p-MAPK, and p-GSK3β were not altered. Cathepsin B, hippocampal p-CREB and BDNF, and hippocampal mitochondrial respiration were not affected by AT or RT. β-Amyloid was ~30% lower in Tg+RT compared to Tg (p<0.05). This data suggests that regular resistance training reduces β-amyloid in the hippocampus concurrent with increased concentrations of IGF-1. Both types of training offered distinct benefits, either by improving physical function or by modifying signals in the hippocampus. Therefore, inclusion of both training modalities may address central defects, as well as peripheral comorbidities in AD.

The physical benefits of a functional exercise circuit are not well known in an elderly population. The purpose of this study was to evaluate the effect of a functional exercise circuit on mobility and perceived health in the elderly. Subjects were 119 men and women (aged 74 [+/-4.2] years) who received pre- and posttests of mobility (e.g., sit to stand, get up and go, timed walk), flexibility (sit and reach), and balance (standing reach) and who completed the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). A supervised functional exercise circuit that included 10 different upper- and lower-body exercises performed under time constraints was performed 3 times per week for 12 consecutive weeks. Paired t-tests showed significant differences at posttest for the get up and go (p < 0.001), standing reach (p < 0.001), sit and reach (p < 0.001), and selected items from the SF-36, including physical functioning (p < 0.001), pain (p = 0.001), vitality (p = 0.001), and number of doctor visits (p < 0.001). A functional exercise circuit such as the one employed in this study may offer promise as an effective means of promoting mobility and perceived health in older adults.

This study examined the acute and resting changes of brain-derived neurotrophic factor (BDNF) and inteleukin-6 (IL-6) and if changes in these biomarkers were correlated during resistance training (RT). Fifteen men with ≥2 years of RT experience (age: 23 ± 3 years, body mass: 84.4 ± 12.3 kg) participated. Subjects performed RT 3×/week for 6 weeks in either a high-repetition (HR; n = 8) or low-repetition (LR; n = 7) group. Protocols during week 1 were HR – Monday: 4 (sets) × 12 (repetitions) at 60% of 1-repetition maximum, Wednesday: 4 × 10 at 65%, Friday: 5 × 8 at 70%; LR – Monday: 8 × 6 at 75%, Wednesday 9 × 4 at 80%, Friday: 10 × 2 at 85%. Total volume was equated for the 6 weeks but not for individual sessions. Greater volume and intensity were performed in LR versus HR (p < 0.01) on Mondays. Plasma was collected immediately before and after exercise of the Monday session. There were no significant interactions or main effects for BDNF (p > 0.05). There was a moderate between-group effect size (0.57) in favor of LR in week 6, suggesting a potentially greater acute increase in BDNF in LR versus HR. For IL-6, a statistically significant main effect was observed for training (p < 0.0001), showing an acute increase in IL-6 in both weeks (p < 0.01); however, no other 3-way or 2-way interactions existed (p > 0.05). A minimum volume threshold of RT may be needed to induce acute elevations in BDNF. Novelty