Effects of Creatine Supplementation on the Myostatin Pathway and Myosin Heavy Chain Isoforms in Different Skeletal Muscles of Resistance-Trained Rats.

Creatine has been used to maximize resistance training effects on skeletal muscles, including muscle hypertrophy and fiber type changes. This study aimed to evaluate the impact of creatine supplementation on the myostatin pathway and myosin heavy chain (MyHC) isoforms in the slow- and fast-twitch muscles of resistance-trained rats. Twenty-eight male Wistar rats were divided into four groups: a sedentary control (Cc), sedentary creatine supplementation (Cr), resistance training (Tc), and resistance training combined with creatine supplementation (Tcr). Cc and Tc received standard commercial chow; Cr and Tcr received a 2% creatine-supplemented diet. Tc and Tcr performed a resistance training protocol on a ladder for 12 weeks. Morphology, MyHC isoforms, myostatin, follistatin, and ActRIIB protein expressions were analyzed in soleus and white gastrocnemius portion samples. The results were analyzed using two-way ANOVA and Tukey's test. Tc and Tcr exhibited higher performance than their control counterparts. Resistance training increased the ratio between muscle and body weight, the cross-sectional area, as well as the interstitial collagen fraction. Resistance training alone increased MyHC IIx and follistatin while reducing myostatin (p < 0.001) and ActRIIB (p = 0.040) expressions in the gastrocnemius. Resistance training induced skeletal muscle hypertrophy and interstitial remodeling, which are more evident in the gastrocnemius muscle. The effects were not impacted by creatine supplementation.

Effectiveness of aquatic exercise in the treatment of inflammatory arthritis: systematic review.

Spondyloarthritis and rheumatoid arthritis are classified as inflammatory arthritis and represent a significant source of pain and disability. Non-pharmacological intervention with physical exercise is among the therapeutic approaches most used by health professionals. This study aimed to investigate the effectiveness of aquatic exercise in the treatment of inflammatory arthritis. The review was registered on the PROSPERO (CRD42020189602). The databases (PubMed, PEDro, Web of Science, and SciELO) were searched for studies involving adults with inflammatory arthritis and subjected to rehabilitation with aquatic exercise compared to any other control group, from the year 2010 to March 2022. Pain, disease activity, and physical function were regarded as primary outcomes. Two reviewers completed the eligibility screening and data extraction, and disagreements were resolved by a third reviewer. The methodological quality was assessed using the PEDro scale. A total of 5254 studies were identified, and nine articles were included, totalling 604 participants. Regarding pain, two studies showed that aquatic exercise was superior to home exercise. One study showed that disease activity was significantly improved in the aquatic group compared to the land-based exercise and the control groups (no exercise). Two studies reported that therapy containing aquatic exercise was able to improve physical function. Overall, the studies included in this review indicate that aquatic exercise is effective in treating pain, disease activity, and physical function in individuals with inflammatory arthritis. However, further studies carrying stronger evidence should be conducted to determine whether the treatment with aquatic exercise is superior to other types of therapies.