The coronavirus disease (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, is leading to unknown and unusual health conditions that are challenging to manage. Post-COVID-19 syndrome is one of those challenges, having become increasingly common as the pandemic evolves. The latest estimates suggest that 10 to 20% of the SARS-CoV-2 patients who undergo an acute symptomatic phase are experiencing effects of the disease beyond 12 weeks after diagnosis. Although research is beginning to examine this new condition, there are still serious concerns about the diagnostic identification, which limits the best therapeutic approach. Exercise programs and physical activity levels are well-known modulators of the clinical manifestations and prognosis in many chronic diseases. This narrative review summarizes the up-to-date evidence on post-COVID-19 syndrome to contribute to a better knowledge of the disease and explains how regular exercise may improve many of these symptoms and could reduce the long-term effects of COVID-19.

To investigate the synergist effects of exercise and β-hydroxy β-methylbutyrate (HMB) supplementation on disability, cognitive and physical function, and muscle power in institutionalized older people. Cluster-randomized controlled trial. Seventy-two institutionalized older adults (age = 83 ± 10 years old; 63% women) were randomized in four groups: exercise plus placebo (EX), HMB supplementation, EX plus HMB supplementation (EX + HMB), and control (CT). The exercising participants completed a 12-week tailored multicomponent exercise intervention (Vivifrail; 5 days/week of an individualized resistance, cardiovascular, balance and flexibility program), whereas the HMB groups received a drink containing 3 g/day of HMB. Participants were assessed Pre and Post intervention for disability and cognitive function (validated questionnaires), physical function (short physical performance battery, SPPB), handgrip strength and sit-to-stand relative muscle power. Linear mixed-effect models were used to compare changes among groups. Compared to baseline, both EX and EX + HMB improved cognitive function (+2.9 and +1.9 points; p < 0.001), SPPB score (+2.9 points and +2.4 points; p < 0.001) and relative muscle power (+0.64 and +0.48 W·kg^-1; p < 0.001), while CT and HMB remained unchanged (p > 0.05). Significant between-group differences were noted between CT, EX and EX + HMB for cognitive function (p < 0.01), between CT and EX + HMB for physical function (p = 0.043), and between CT, EX and EX + HMB for relative muscle power (p < 0.001). The Vivifrail exercise program was effective in improving cognitive and physical function, and muscle power in nursing home residents, while HMB supplementation did not provide additional benefits when combined with exercise. These results emphasize the importance of physical exercise interventions in very old people as an essential basis for improving their overall health and quality of life.

Background: Although the superior effectiveness of free‐weight over machine‐based training has been a traditionally widespread assumption, longitudinal studies comparing these training modalities were scarce and heterogeneous.Objective: This research used the velocity‐based method to compare the effects of free‐weight and machine‐based resistance training on athletic performance and muscle architecture.Methods: Thirty‐four resistance‐trained men participated in an 8‐week resistance training program allocated into free‐weight (n = 17) or machine‐based (n = 17) groups. Training variables (intensity, intraset fatigue, and recovery) were identical for both groups, so they only differed in the use of a barbell or specific machines to execute the full squat, bench press, prone bench pull, and shoulder press exercises. The velocity‐based method was implemented to accurately adjust the planned intensity. Analysis of covariance and effect size (ES) statistics were used to compare both training modalities on a comprehensive set of athletic and muscle architecture parameters.Results: No between‐group differences were found for any athletic (p ≥ 0.146) and muscle architecture (p ≥ 0.184) variable. Both training modalities significantly and similarly improved vertical jump (Free‐weight: ES ≥ 0.45, p ≤ 0.001; Machine‐based: ES ≥ 0.41, p ≤ 0.001) and lower limb anaerobic capacity (Free‐weight: ES ≥ 0.39, p ≤ 0.007; Machine‐based: ES ≥ 0.31, p ≤ 0.003). Additionally, the machine‐based group meaningfully enhanced upper limb anaerobic power (ES = 0.41, p = 0.021), whereas the free‐weight group significantly improved the change of direction (ES = ‐0.54, p = 0.003) and 2/6 balance conditions analyzed (p ≤ 0.012). Changes in sprint capacity (ES ≥ ‐0.13, p ≥ 0.274), fascicle length, and pennation angle (ES ≤ 0.19, p ≥ 0.129) were not significant for either training modality.Conclusion: Adaptations in athletic performance and muscle architecture would not be meaningfully influenced by the resistance modality trained.

This study aimed to examine the sensitivity of the isometric knee extension (IKE) test to detect changes in the lower-limb strength of institutionalized older adults after exercise and inactivity periods. Thirty-four and fifteen institutionalized older adults completed the training and inactive periods, respectively. At each time point, the participants completed two testing sessions. In the first session, they performed the IKE test. As a complement to this evaluation, the second testing session was used to assess their functional capacity and handgrip strength. The sensitivity of the IKE test was examined by comparing the changes generated in this test against the repeatability of the protocol. A 4-week multicomponent Vivifrail program was implemented. After that, a subsample of the participants was re-evaluated after a 14-week inactivity period. Significant changes (p < 0.01; ES ≥ 0.27) in the IKE strength for both the dominant (+0.27 N/kg) and non-dominant legs (+0.25 N/kg) were produced after the training intervention. Likewise, significant decrements (p < 0.01; ES ≥ 0.31) were detected after the inactive period for the dominant (−0.29 N/kg) and non-dominant legs (−0.32 N/kg). All mean changes were found to be superior to the variability threshold of the IKE test for both legs, with superior sensitivity for the non-dominant leg (≥73%). Thus, the IKE test is a sensitive and practical tool for detecting changes in the lower-limb strength of institutionalized older adults after exercise and inactivity periods. Because of its applicability, it seems pertinent to implement the IKE test in a geriatric context.

We examined the effect of breast cancer surgery and adjuvant therapy on the relationship between bar velocity and relative intensity (load-velocity [L-V] relationship) of the bench press (BP) exercise. Twenty-two breast cancer survivors (age: 48.0±8.2 yr., relative strength: 0.40±0.08) completed a loading test up to the one-repetition maximum (1RM) in the BP using a lightweight carbon bar. General and individual relationships between relative intensity (%1RM) and mean propulsive velocity (MPV) were studied. Furthermore, the mean test velocity (MPV_Test) and velocity attained to the 1RM (MPV_1RM) were analyzed. These procedures and analyses were also conducted in 22 healthy women (age: 47.8±7.1 yr., relative strength: 0.41±0.09) to examine the differences in velocity parameters derived from these L-V relationships. Polynomial regressions showed very close relationships (R²≥0.965) and reduced estimation errors (≤4.9% 1RM) for both groups. Between-group differences in MPV attained to each %1RM were small (≤0.01 m·s⁻¹) and not significant (p≥0.685). Similarly, the MPV_Test (0.59±0.06 m·s⁻¹) and MPV_1RM (0.17±0.03 m·s⁻¹) were identical for breast cancer survivors and healthy women. These results suggest that practitioners could use the same velocity parameters derived from the BP L-V relationship to prescribe this exercise in middle-aged women, regardless of whether they have suffered from breast cancer. Received: 02 August 2023 Accepted: 06 September 2023 Article published online: 13 November 2023 © 2023. Thieme. All rights reserved. Georg Thieme Verlag Rüdigerstraße 14, 70469 Stuttgart, Germany

Exercise is a front-line intervention to increase functional capacity and reduce pain and disability in people with low strength levels or disorders. However, there is a lack of validated field-based tests to check the initial status and, more importantly, to control the process and make tailored adjustments in load, intensity, and recovery. We aimed to determine the test–retest reliability of a submaximal, resistance-band test to evaluate the strength of the trunk stability muscles using a portable force sensor in middle-aged adults (48 ± 13 years) with medically diagnosed chronic low back pain and healthy peers (n = 35). Participants completed two submaximal progressive tests of two resistance-band exercises (unilateral row and Pallof press), consisting of 5 s maintained contraction, progressively increasing the load. The test stopped when deviation from the initial position by compensation movements occurred. Trunk muscle strength (CORE muscles) was monitored in real time using a portable force sensor (strain gauge). Results revealed that both tests were highly reliable (intra-class correlation [ICC] > 0.901) and presented low errors and coefficients of variation (CV) in both groups. In particular, people with low back pain had errors of 14–19 N (CV = 9–12%) in the unilateral row test and 13–19 N (CV = 8–12%) in the Pallof press. No discomfort or pain was reported during or after the tests. These two easy-to-use and technology-based tests result in a reliable and objective screening tool to evaluate the strength and trunk stability in middle-aged adults with chronic low back pain, considering an error of measurement < 20 N. This contribution may have an impact on improving the individualization and control of rehabilitation or physical training in people with lumbar injuries or disorders.