The Acute, Combined, and Separate Effects of Cold Hemodialysis and Intradialytic Exercise in Insulin Sensitivity and Glucose Disposal.

Hemodialysis (HD) patients suffer from multiple health problems, including severe insulin resistance. Both cold dialysis and intradialytic exercise training could elicit health benefits; however, it is still unknown whether the combination of those two approaches could enhance overall health. The current study aimed to evaluate the separate and combined acute effects of a single session of cold dialysis and intradialytic exercise in parameters related to insulin sensitivity and glucose disposal. Ten HD patients (57.2 ± 14.9 years) participated in the study. Each patient participated in four different scenarios during HD: a) typical dialysis with dialysate temperature at 37°C (TD), b) cold dialysis with dialysate temperature at 35°C, c) typical HD combined with a single exercise bout, d) cold dialysis combined with a single exercise bout. Glucose disposal and insulin resistance were assessed immediately after the end of the HD session. None of the examined parameters significantly differed between the four scenarios ( p > 0.05). However, slight numerical changes and moderate to high effect size ( d : 0.50-0.85) were observed between TD versus cold dialysis and TD versus TD + exercise in glucose and insulin disposal rates. A single session of cold and TD with intradialytic exercise may provide an "acute" time-efficient stimulus for consecutively improving glucose disposal and insulin sensitivity.

Seven months of aerobic intradialytic exercise training can prevent muscle loss in haemodialysis patients: an ultrasonography study.

PURPOSE: This study aimed to evaluate the effects of 7-month intradialytic exercise training (IDE) on vastus lateralis (VL) muscle architecture, functional capacity and quality of life in stable haemodialysis (HD) patients. METHODS: 44 HD patients were randomly assigned into an Exercise Group (EG = 21), which they received 7 months of IET, at 60% of pre-assessed maximum aerobic power, 3/week) or into a Control Group (CG = 23, no exercise). VL architecture was evaluated with ultrasonography, functional capacity was assessed using a series of functional tests (6 min walking test, 5 repetitions sit-to-stand, sit-to-stand 60 s, handgrip strength), and maximal aerobic power determined with a modified version of the Åstrand test. Quality of life and fatigue levels were evaluated using validated questionnaires. RESULTS: VL fascicle angle and length did not change significantly in both groups (P > 0.05). Muscle thickness decreased in CG (P = 0.02) while it was fully preserved in the EG. Functional capacity increased only in the EG (6 min walking test 15.79 ± 12.35%, P < 0.001; max aerobic power 26.36 ± 1.24%, P < 0.001; STS-60rep: 10.23 ± 1.60%, P < 0.000; hand grip strength: 5.14 ± 28.30%, P < 0.02). CONCLUSION: Intradialytic aerobic exercise training, improves functional capacity and prevents thigh muscle mass loss in HD patients. It is evident that muscle ultrasonography could play a pivotal role in assessing muscle quality changes in haemodialysis patients. A higher level of training intensity or combination with resistance exercises may be required to further improve anabolism and influence muscle architecture in this patient population. CLINICAL TRIAL REGISTRY NUMBER: NCT03905551.

The effects of training with high-speed interval running on muscle performance are modulated by slope.

We examined changes in selected muscle performance parameters after 8 weeks of interval training using two opposite running inclinations. We hypothesized that the uphill training will affect endurance muscle performance outcomes, whereas the downhill training will affect power muscle performance outcomes. Fourteen physically active volunteers were randomly assigned into either the Uphill group (UG; n = 7; uphill interval running at +10% incline) or the Downhill group (DG; n = 7; downhill interval running at -10% incline) and completed 16 training sessions. Each session consisted of ten 30 s treadmill runs at 90% of maximum aerobic speed (MAS) with a work to rest ratio of 1:2. Vertical jump performance, isometric (MVC) and isokinetic torque of knee extensors and flexors, and fatigue of knee extensors were evaluated pre and post-training. Moreover, body composition (via bioimpedance) and vastus lateralis muscle architecture (via ultrasonography) were assessed pre and post-training. Relative lean tissue mass, relative fat mass, and squat jump (cm) significantly (p < .05) changed from baseline values by +4.5 ± 4.0%, -11.5 ± 9.6%, and +9.5 ± 11.7%, respectively, only in the DG. Similarly, DG improved absolute values of knee extension rate of torque development and impulse (p < .05), whereas knee flexion peak torque angle significantly decreased in both groups (p < .05). On the other hand, the UG increased the number of repetitions achieved during the fatigue protocol and total work by 21.2 ± 32.6% and 13.8 ± 21.2%, respectively (p < .05). No differences were found between groups in muscle architecture. Introducing variations in slope during HIIT could be used to induce specific improvements toward muscle endurance or power performance characteristics.

Long-term intradialytic hybrid exercise training on fatigue symptoms in patients receiving hemodialysis therapy.

PURPOSE: Hemodialysis (HD) patients suffer from generalized weakness, exercise intolerance and muscle atrophy, all leading to generalized fatigue and lack of energy. HD patients spend at least 50% of their time in a functionally "switch off" mode with their fatigue sensations reaching a peak in the immediate hours after the dialysis session. The purpose of the current study was to assess the effectiveness of a nine-month hybrid intradialytic exercise program on fatigue symptoms occurring during and after hemodialysis session. METHODS: Twenty stable hemodialysis patients were included in the study (59 ± 13.7 years; 16 males). All patients completed a 9-month supervised exercise training program composed of both aerobic cycling and resistance training during HD. Aspects related to physical and generalized fatigue were assessed via validated questionnaires, while physical performance was assessed by a battery of tests, before and after the intervention period. RESULTS: Exercise capacity and physical performance were increased by an average of 65 and 40%, respectively. Patients reported feeling better during post-dialysis hours in question 1 (p = 0.000), question 3 (p = 0.009) and question 4 (p = 0.003) after the 9-month intervention. In addition, exercise training improved scores in cognitive function (p = 0.037), vitality (p = 0.05), depression (p = 0.000) and fatigue (p = 0.039). CONCLUSION: The present study showed that a 9-month hybrid (aerobic + resistance) exercise training program improved symptoms of post-dialysis fatigue and overall general perception of fatigue. Hybrid exercise training is a safe and effective non-pharmacological approach to ameliorate fatigue symptoms in HD patients. TRIAL REGISTRATION NUMBER: Trial registration number The study is registered at ClinicalTrials.gov (NCT01721551, 2012) as a clinical trial.

Separate and combined effects of cold dialysis and intradialytic exercise on the thermoregulatory responses of hemodialysis patients: a randomized-cross-over study.

BACKGROUND: The separate and combined effects of intradialytic exercise training (IET) and cold dialysis (CD) on patient thermoregulation remain unknown. This study assessed the thermoregulatory responses of hemodialysis patients under four different hemodialysis protocols: a) one typical dialysis (TD) protocol (dialysate temperature at 37 °C), b) one cold dialysis (CD) protocol (dialysate temperature at 35 °C), c) one typical dialysis protocol which included a single exercise bout (TD + E), d) one cold dialysis protocol which included a single exercise bout (CD + E). METHODS: Ten hemodialysis patients (57.2 ± 14.9 years) participated in this randomized, cross-over study. Core and skin temperatures were measured using an ingestible telemetric pill and by four wireless iButtons attached on the skin, respectively. Body heat storage (S) calculated using the thermometric method proposed by Burton. RESULTS: The TD and TD + E protocols were associated with increased S leading to moderate effect size increases in core body temperature (as high as 0.4 °C). The low temperature of the dialysate during the CD and the CD + E protocols prevented the rise in S and core temperature (p > 0.05), even during the period that IET took place. CONCLUSIONS: TD and IET are accompanied by a moderate level of hyperthermia, which can be offset by CD. We recommended that CD or with IET can prevent the excessive rise of S. TRIAL REGISTRATION: Clinical Trial Registry number: NCT03905551 ( clinicaltrials.gov ), DOR: 05/04/2019.

The Effect of Cold Dialysis in Motor and Sensory Symptoms of RLS/WED Occurring During Hemodialysis: A Double-Blind Study.

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a common sensorimotory disorder affecting almost 30% of hemodialysis (HD) patients. RLS/WED induces discomfort during rest hours, and its symptoms have also been observed during HD sessions. Anecdotal reports suggest that cooling the dialysate solution during dialysis could help patients overcome those symptoms and improve restlessness. The aim of this double-blind study was to assess whether a reduction of the dialysate temperature by 1°C could reduce motor and sensory symptoms of RLS/WED occurring during HD. Thirty-two HD patients participated in the study. Patients were divided into two groups: the RLS (N=16) and the non-RLS groups (N=16). Patients were studied on two different scenarios for two consecutive HD sessions, 1 week apart: 1) standard temperature of the dialysate (37°C) and 2) low temperature of the dialysate (36°C cold dialysis scenario). In all sessions, motor (leg movement per hour of HD [LM/hHD]) and sensory symptoms were assessed. The reduction of dialysate temperature by 1°C was effective in reducing motor symptoms as they assessed the LM/hHD by 36% only in patients with RLS, while a significant interaction was found between "LM/hHD affected by temperature" and "RLS status" (p = 0.039). Sensory symptoms also reduced by 10% after the reduction of the dialysate temperature. The reduction of the dialysate temperature by 1°C reduced motor symptoms by 36-54% and sensory symptoms by 10% in HD patients with RLS/WED. Cold dialysis could be considered a safe nonpharmacological approach for the amelioration of RLS/WED symptoms occurring during HD.

Rate of Force Development, Muscle Architecture, and Performance in Young Competitive Track and Field Throwers.

The rate of force development (RFD) is an essential component for performance in explosive activities, although it has been proposed that muscle architectural characteristics might be linked with RFD and power performance. The purpose of the study was to investigate the relationship between RFD, muscle architecture, and performance in young track and field throwers. Twelve young track and field throwers completed 10 weeks of periodized training. Before (T1) and after (T2) training performance was evaluated in competitive track and field throws, commonly used shot put tests, isometric leg press RFD, 1 repetition maximum (1RM) strength as well as vastus lateralis architecture and body composition. Performance in competitive track and field throwing and the shot put test from the power position increased by 6.76 ± 4.31% (p < 0.001) and 3.58 ± 4.97% (p = 0.019), respectively. Rate of force development and 1RM strength also increased (p ≤ 0.05). Vastus lateralis thickness and fascicle length increased by 5.95 ± 7.13% (p = 0.012) and 13.41 ± 16.15% (p = 0.016), respectively. Significant correlations were found at T1 and T2, between performance in the shot put tests and both RFD and fascicle length (p ≤ 0.05). Close correlations were found between RFD, muscle thickness, and fascicle length (p ≤ 0.05). Significant correlations were found between the % changes in lean body mass and the % increases in RFD. When calculated together, the % increase in muscle thickness and RFD could predict the % increase in shot put throw test from the power position (p = 0.019). These results suggest that leg press RFD may predict performance in shot put tests that are commonly used by track and field throwers.

Effects of tapering with light vs. heavy loads on track and field throwing performance.

The purpose of the study was to investigate the effects of power training with light vs. heavy loads during the tapering phases of a double periodized training year on track and field throwing performance. Thirteen track and field throwers aged 16-26 years followed 8 months of systematic training for performance enhancement aiming at 2 tapering phases during the winter and the spring competition periods. Athletes performed tapering with 2 different resistance training loads (counterbalanced design): 7 athletes used 30% of 1 repetition maximum (1RM) light-load tapering (LT), and 6 athletes used the 85% of 1RM heavy-load tapering (HT), during the winter tapering. The opposite was performed at the spring tapering. Before and after each tapering, throwing performance, 1RM strength, vertical jumping, rate of force development (RFD), vastus lateralis architecture, and rate of perceived exertion were evaluated. Throwing performance increased significantly by 4.8 ± 1.0% and 5.6 ± 0.9% after LT and HT, respectively. Leg press 1RM and squat jump power increased more after HT than LT (5.9 ± 3.2% vs. -3.4 ± 2.5%, and 5.1 ± 2.4% vs. 0.9 ± 1.4%, respectively, p ≤ 0.05). Leg press RFD increased more in HT (38.1 ± 16.5%) compared with LT (-2.9 ± 6.7%), but LT induced less fatigue than HT (4.0 ± 1.5 vs. 6.7 ± 0.9, p ≤ 0.05). Muscle architecture was not altered after either program. These results suggest that performance increases similarly after tapering with LT or HT in track and field throwers, but HT leads to greater increases in strength, whole body power, and RFD.