Purpose: To investigate the effects of thirst on later hydration status, total water intake (TWI-MA), and its potential sex differences. Methods: Twelve men (mean ± standard deviation; age: 21 ± 2 years; mass: 81.0 ± 15.9 kg) and twelve women (age: 22 ± 3 years; mass: 68.8 ± 15.2 kg) visited the laboratory in the morning (first thing in the morning) and afternoon (2:00–4:00 p.m.) for three consecutive days under a free-living condition. At each visit, urine osmolality (U_OSM), urine specific gravity (USG), urine color (U_COL), body mass loss (BML), thirst, and plasma osmolality (P_OSM) were collected and analyzed. The participants recorded their food and fluid intake between the visits to determine TWI-MA. Linear regression was used to predict the effect of morning thirst on the afternoon hydration indices for all the participants, as well as for males and females separately. Results: Higher morning thirst predicted lower U_OSM (r² = 0.056, p = 0.045), USG (r² = 0.096, p = 0.008), U_COL (r² = 0.074, p = 0.021), and higher thirst (r² = 0.074, p = 0.021) in the afternoon. However, morning thirst did not predict afternoon BML, P_OSM, or TWI-MA (p > 0.05). In males, higher morning thirst predicted lower afternoon U_OSM (r² = 0.130, p = 0.031) and USG (r² = 0.153, p = 0.018). Additionally, higher morning thirst predicted higher TWI-MA (r² = 0.154, p = 0.018) in females. Conclusions: Morning thirst had a negligible impact on later hydration status, specifically with afternoon urine indices. Furthermore, higher thirst sensation did not impact BML, P_OSM, or TWI-MA. However, thirst sensation minimally contributed to drinking behavior in females. Overall, individuals may not rely solely on thirst sensation to manipulate their drinking behavior to optimize their fluid balance during their daily lives due to the complexity of thirst mechanisms.

Objectives: The WUT (weight, urine color, thirst) Venn diagram has been demonstrated as a practical tool for hydration assessment. However, no investigations have examined if there are sex differences in the accuracy of this method. Therefore, the purpose of this study was to explore potential sex differences in the accuracy of the WUT Venn diagram for hydration status determination. Methods: Twelve men (21 ± 2 years; 81.0 ± 15.9 kg) and twelve women (22 ± 3 years; 68.8 ± 15.2 kg) completed the study. Body mass, urine color, urine specific gravity (USG), urine osmolality (UOSM), thirst level, and plasma osmolality (POSM) were collected at first-morning and afternoon visits for three consecutive days in free-living and euhydrated states. The number of markers indicating dehydration levels were categorized into either 3, 2, 1, or 0 WUT markers. Receiver-operating characteristics analysis calculated the sensitivity and specificity of 1, 2, or 3 hydration markers in detecting dehydration or euhydration. Results: WUT2 and WUT3 resulted in high specificity values in comparison to USG (WUT2—male: 0.912, female: 0.949; WUT3—male: 0.991, female: 1.000), UOSM (WUT2—male: 0.901, female: 0.946; WUT3—male: 0.991, female: 1.000), and POSM (WUT2—male: 0.859, female: 0.896 WUT3; male: 0.977, female: 0.991). WUT1 resulted in high sensitivity values compared to USG (male: 0.931, female: 0.857), but varied between sexes for UOSM (male: 0.875, female: 0.794) and POSM (male: 0.469, female:0.536). Conclusions: The WUT Venn diagram accurately detects dehydration when two or three WUT markers are met in both males and females. The WUT Venn diagram accurately assesses hydration status in males and females, thus providing medical personnel and athlete support teams a cost-effective and time-efficient hydration testing tool.

Type 2 diabetes (T2D) is associated with increased inflammation and reactive oxygen species (ROS) in muscles, leading to basal satellite cell (SC) myogenic impairment (i.e., reduction in SC pool), which is critical for maintaining skeletal muscle mass. T2D may contribute to muscle atrophy, possibly due to reductions in the SC pool. Geranylgeraniol (GGOH) and ginger can reduce inflammation and enhance SC myogenesis in damaged muscles, thereby alleviating muscle atrophy; however, their effect on basal SC myogenic state and muscle mass in T2D rats is limited. Rats consumed a control diet (CON), high-fat diet with 35 mg/kg of streptozotocin (HFD), a HFD with 800 mg/kg body weight of GGOH (GG), or a HFD with 0.75% ginger root extract (GRE). In the eighth week, their soleus muscles were analyzed for Pax7, MyoD, and MSTN gene and protein expression, SC myogenic state, and muscle cross-sectional area (CSA). The HFD group had a significantly lower number of Pax7⁺/MyoD⁻ and Pax7⁺/MSTN⁺ cells, less Pax7 and MyoD gene expression, and less MyoD and MSTN protein expression, with a smaller CSA than the CON group. Compared to the GG and GRE groups, the HFD group had a significantly lower number of Pax7⁺/MSTN⁺ cells, less MyoD protein expression, and smaller CSA. The GRE group also had a significantly lower number of Pax7⁻/MyoD⁺ and greater MSTN protein expression than the HFD group. Nevertheless, the CON group had a significantly greater number of Pax7⁺/MyoD⁻ than the GG and GRE groups, and a greater number of Pax7⁻/MyoD⁺ cells than the GRE group with a larger CSA than the GG group. GGOH and ginger persevered muscle CSA, possibly through increased MyoD and the ability to maintain the SC pool in T2D rats.

Denervation-induced calcium/calmodulin-dependent protein kinase II (CaMKII) activation and inflammation can result in muscle atrophy. Curcumin and bisdemethoxycurcumin are well known to exhibit an anti-inflammatory effect. In addition, curcumin has been shown to attenuate CaMKII activation in neuronal cells. This study aimed to examine the effect of curcumin or bisdemethoxycurcumin on CaMKII activation, inflammation, and muscle cross-sectional area (CSA) in spinal nerve ligated rats. Sixteen female rats were assigned to sham (CON), spinal nerve ligation (SNL), SNL+ curcumin 100 mg/kg BW (100CUR), and SNL+ bisdemethoxycurcumin 50 mg/kg BW (50CMO) for 4 weeks. Ipsilateral (surgical) soleus and tibialis anterior (TA) muscles was stained for dystrophin to measure CSA. Ipsilateral and contralateral (non-surgical) plantaris muscles were analyzed for protein content for acetylcholine receptor (AChR), CaMKII, CaMKII^Thr286, nuclear factor-κB (NF-κB), NF-κB^Ser536, and interleukin-1β (IL-1β) and normalized to α-tubulin and then CON. A significant (p < 0.050) group effect was observed for TA CSA where CON (11,082.25 ± 1617.68 μm²; p < 0.001) and 100CUR (9931.04 ± 2060.87 μm²; p = 0.018) were larger than SNL (4062.25 ± 151.86 μm²). In the ipsilateral plantaris, the SNL (4.49 ± 0.69) group had greater CaMKII activation compared to CON (1.00 ± 0.25; p = 0.010), 100CUR (1.12 ± 0.45; p = 0.017), and 50CMO (0.78 ± 0.19; p = 0.009). The ipsilateral plantaris (2.11 ± 0.66) had greater IL-1β protein content than the contralateral leg (0.65 ± 0.14; p = 0.041) in the SNL group. In plantaris, the SNL (1.65 ± 0.51) group had greater NF-κB activation compared to CON (1.00 ± 0.29; p = 0.021), 100CUR (0.61 ± 0.10; p = 0.003), 50CMO (0.77 ± 0.25; p = 0.009) groups. The observed reduction in Ca²⁺ signaling and inflammation in type II plantaris muscle fibers might reflect the changes within the type II TA muscle fibers which may contribute to the mitigation of TA mass loss with curcumin supplementation.

Jiwan, NC, DeKuiper, KJ, Sysol, LA, Chabala, GE, and Costa, PA. Passive heating via heating pads improves vertical jump and agility performance in NCAA Division III soccer players. J Strength Cond Res XX(X): 000–000, 2026—Passive heating may enhance performance by increasing blood flow, improving nerve conduction, and stimulating calcium release. Although most studies focus on saunas or hot water immersion, research on heating pads (HP) remains limited. Thus, this study aims to investigate the effect of HP on athletic performance in soccer players. Nineteen male ( n = 10) and female ( n = 9) soccer players completed 2 identical testing sessions in a randomized, counterbalanced design. HP was applied to both thighs and set to 66°C in the passive heat treatment (PHT) and maintained at body temperature in the sham condition. Skin temperature was taken before (Pre) and after (Post) HP application. After heating, subjects completed 3 performance tests: passing accuracy, vertical jump, and agility t test. Peak power was derived from vertical jump height (VJH). The alpha level was set at p ≤ 0.05. PHT significantly increased thigh skin temperature, improved VJH, peak power, and agility times, while no differences were observed for passing accuracy. PHT improved VJH and agility times in soccer players, supporting HP as an accessible and effective preactivity strategy to enhance performance.