News & Views from the Editor-in-Chief - L. Bruce Gladden
I am highlighting three papers of particular interest in this month's journal. First, Husmann et al. provide mechanistic insight into the etiology of muscle fatigue development and recovery when low-intensity exercise is combined with blood flow restriction (BFR). The authors found that BFR exacerbated the development of muscle fatigue mainly due to a strong decline in contractile function. Despite the significantly higher level of muscle fatigue during BFR exercise, the effect of limited blood flow was diminished after 2 min of reperfusion, suggesting that BFR induced strong but short-lasting impairments in neuromuscular function. These results provide additional evidence supporting the utility of BFR in resistance training.
Next, Galvão et al. examined the efficacy and safety of a modular multimodal exercise program in 57 prostate cancer patients with bone metastases. They found that exercise in prostate cancer patients with bone metastases led to improvements in self-reported physical function as well as objectively measured lower body muscle strength with no skeletal complications or increased bone pain. These changes are likely to be clinically meaningful to patients and advances the field of exercise oncology as the presence of bone metastases has excluded participation of cancer patients in exercise interventions and is a relative contraindication to supervised exercise in the community setting due to concerns of fragility fracture. Further, the exercise protocol could be replicated on a larger scale using the modular targeted exercise program whereby exercise can be performed without the bone metastatic lesions being loaded.
In the third article, Howden et al. sought to characterize the effects of sedentary aging and lifelong exercise training on measures of systolic cardiac function. Sedentary seniors demonstrated an impairment in longitudinal strain even after accounting for differences in left ventricular filling pressures when compared with young sedentary and well-trained, age-matched seniors. Exercise training for more than four days per week over a period of 25 years, maintained longitudinal strain at levels comparable to those observed in sedentary young individuals. This improvement in the trained seniors' longitudinal strain was principally due to enhanced diastolic filling, as afterload was unaffected. Similar to other Doppler measures, longitudinal strain by speckle tracking imaging appears to be sensitive to changes in left ventricular loading conditions, thus left ventricular loading should be carefully considered when interpreting these types of findings.
L. Bruce Gladden
School of Kinesiology