Combined training improves the diagnostic measures of sarcopenia and decreases the inflammation in HIV-infected individuals.

BACKGROUND: HIV-related sarcopenia is an emerging health issue that often remains undiagnosed and can lead to reduced quality of life, independence, and premature death if untreated. This study investigated the effects of a 6 month combined training (resistance plus aerobic exercise) (CT) intervention on diagnostic measures of sarcopenia, including grip strength, appendicular lean mass index (ALMI), and gait speed. METHODS: Forty participants were randomized into either a CT group (n = 20; age = 38.3 ± 4.9 years) or a control group (CON; n = 20; age = 37.9 ± 5.1 years). Participants in the CT group performed three supervised sessions per week for 6 months, consisting of weekly reverse linear periodized resistance training followed by 20 min aerobic training. Participants in the CON group were instructed to continue with their current lifestyle habits. Assessments were completed at baseline and after 6 months. Statistical analyses were performed using a two-way analysis of covariance (ANCOVA) adjusted for sex and preintervention values. Primary outcomes included grip strength, ALMI, and gait speed. Secondary outcomes were changes in levels of pro-inflammatory cytokines (IL-6 and TNF-α), IGF-1, and myostatin. Associations were explored between changes in inflammatory markers (IL-6 and TNF-α), gait speed, and ALMI with grip strength. RESULTS: A significant increase in ALMI was found for CT compared with CON (0.29 ± 0.13 kg/m2 vs. -0.11 ± 0.14 kg/m2 , respectively; P < 0.001). Significant improvements in grip strength (7.86 ± 8.50 kg for CT vs. -1.58 ± 2.47 kg for CON) and gait speed (0.16 ± 0.07 m/s2 for CT vs. -0.06 ± 0.52 m/s2 for CON; both P < 0.001) were also observed in CT compared with CON. Reduction in inflammatory biomarkers was found in CT compared with CON (IL-6; TNF-α, both P < 0.001). An increase in IGF-1 (74.36 ± 56.64 pg/mm3 for CT vs. 7.19 ± 99 pg/mm3 for CON; P < 0.001) and a decrease in myostatin (-158.90 ± 62.03 pg/mm3 for CT vs. -43.33 ± 146.60 pg/mm3 for CON; P < 0.001) was found following CT compared with the CON group. Change in grip strength was correlated with changes in IL-6 (r = -0.65, P < 0.001), TNF-α (r = -0.63, P < 0.001), gait speed (r = 0.63, P < 0.001), and ALMI (r = 0.54, P = 0.001), but not IGF-1 and myostatin. No adverse events were recorded, and compliance with the CT exercise sessions was high (>85%). CONCLUSIONS: Combined training appears to be an effective means to counteract sarcopenia and improve various inflammatory markers and growth hormones in people living with HIV.

Is Perceived Exertion a Useful Indicator of the Metabolic and Cardiovascular Responses to a Metabolic Conditioning Session of Functional Fitness?

The purpose of this study was to assess whether the self-regulation of training intensity based on rating of perceived exertion (RPE) is a reliable method to control the intensity during metabolic conditioning sessions of functional fitness. In addition, the relationship between RPE and the changes in heart rate, number of repetitions, and lactate responses was also analyzed. Eight male participants (age 28.1 ± 5.4 years; body mass 77.2 ± 4.4 kg; VO2 max: 52.6 ± 4.6 mL·(kg·min)-1 completed two sessions (five to seven days apart), in a randomized order, under different conditions, as follows: (1) all-out (ALL), or (2) self-regulation of intensity based on an RPE of six (hard) on the Borg CR-10 scale (RPE6). The rating of perceived exertion, lactate (LAC), and heart rate (HR) response were measured before, during, and immediately after the sessions. The RPE and LAC during the all-out sessions were higher (p < 0.0005) than the RPE6 session for all of the analyzed time points during the session. There was no difference in the HR area under the curve for the all-out and RPE6 sessions. The average number of repetitions performed was lower (p ≤ 0.009) for the RPE6 session (190.5 ± 12.5 repetitions) when compared to the all-out session (214.4 ± 18.6 repetitions). There was a significant correlation between the RPE and LAC (p = 0.005; r = 0.66; large) and number of repetitions during the session (p = 0.026; r = 0.55; large). No correlation was observed between the RPE and HR (p = 0.147; r = 0.380). These results indicate that the self-regulation of intensity of effort based on the RPE may be a useful tool to control the exercise intensity during a metabolic conditioning session of functional fitness.

Evaluation of efforts in untrained Wistar rats following exercise on forced running wheel at maximal lactate steady state.

PURPOSE: We aimed to examine the effect of running speed on metabolic responses associated with maximal lactate steady state (MLSS) in rats during forced running wheel (FRW) exercise. METHODS: Forty male adult Wistar rats were divided into seven groups. The blood lactate threshold and peak running speed were determined for an incremental power test group. Five groups participated in constant power tests at intensities 10, 13, 14.5, 16, and 17.5 m/min to determine MLSS and a non-exercise group was chosen as the control. Animals were euthanized immediately after constant power tests and their corticosterone, non-esterified fatty acid (NEFA), blood glucose, and creatine kinase (CK) levels analyzed. The differences among groups were identified by one-way analysis of variance (p < 0.05). RESULTS: Blood lactate threshold corresponded a running intensity of 15 m/min, while MLSS was determined to be 16 m/min. Serum corticosterone concentrations were significantly higher in 14.5, 16, and 17.5 m/min groups (298.8±62, 338.3±65, and 354±26 nM, respectively) as compared to that in the control group (210.6±16 nM). Concentrations of NEFA observed in groups 13, 14.5, 16, and 17.5 m/min (662.8±24, 702.35±69, 718.4±34, and 752.8±77 µM, respectively) were significantly higher than those in 10 m/min and control groups (511.1±53 and 412.1±56 µM, respectively). The serum CK concentration recorded for group 17.5 m/min (372.4±56 U/L) was higher than those recorded for other groups. CONCLUSION: The speed above 16 m/min on FRW resulted in increased physiological demands and muscle damage in untrained healthy Wistar rats.