This study analyzed the effects of pseudoephedrine (PSE) provided at different time of day on neuromuscular performance, side effects, and violation of the current doping cut‐off threshold World ...Anti‐Doping Agency (WADA). Nine resistance‐trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75%, and 90% one repetition maximum 1RM), in a randomized, double‐blind, cross‐over design. Participants ingested either 180 mg of PSE (supra‐therapeutic dose) or placebo in the morning (7:00 h; AMPLAC and AMPSE) and in the afternoon (17:00 h; PMPLAC and PMPSE). PSE enhanced muscle contraction velocity against 25% and 50% 1RM loads, only when it was ingested in the mornings, and only in the full squat exercise (4.4–8.7%; P < 0.05). PSE ingestion raised urine and plasma PSE concentrations (P < 0.05) regardless of time of day; however, cathine only increased in the urine samples. PSE ingestion resulted in positive tests occurring in 11% of samples, and it rose some adverse side effects such us tachycardia and heart palpitations. Ingestion of a single dose of 180 mg of PSE results in enhanced lower body muscle contraction velocity against low and moderate loads only in the mornings. These mild performance improvements are accompanied by undesirable side effects and an 11% risk of surpassing the doping threshold.
Caffeine supplementation (CAFF) has an established ergogenic effect on physical performance and the psychological response to exercise. However, few studies have compared the response to CAFF intake ...among athletes of different competition level. This study compares the acute effects of CAFF on anaerobic performance, mood and perceived effort in elite and moderately-trained recreational athletes.
Participants for this randomized, controlled, crossover study were 8 elite athletes (in the senior boxing national team) and 10 trained-recreational athletes. Under two experimental conditions, CAFF supplementation (6 mg/kg) or placebo (PLAC), the athletes completed a Wingate test. Subjective exertion during the test was recorded as the rating of perceived exertion (RPE) both at the general level (RPE
) and at the levels muscular (RPE
) and cardiorespiratory (RPE
). Before the Wingate test, participants completed the questionnaires Profiles of Moods States (POMS) and Subjective Vitality Scale (SVS).
In response to CAFF intake, improvements were noted in W
(11.22 ± 0.65 vs 10.70 ± 0.84; p = 0.003; Formula: see text =0.44), W
(8.75 ± 0.55 vs 8.41 0.46; p = 0.001; Formula: see text =0.53) and time taken to reach W
(7.56 ± 1.58 vs 9.11 ± 1.53; p < 0.001; Formula: see text =0.57) both in the elite and trained-recreational athletes. However, only the elite athletes showed significant increases in tension (+ 325%), vigor (+ 31%) and SVS (+ 28%) scores after the intake of CAFF compared to levels recorded under the condition PLAC (p < 0.05). Similarly, levels of vigor after consuming CAFF were significantly higher in the elite than the trained-recreational athletes (+ 5.8%).
CAFF supplementation improved anaerobic performance in both the elite and recreational athletes. However, the ergogenic effect of CAFF on several mood dimensions and subjective vitality was greater in the elite athletes.
Handball performance is a team-sport characterized by high intensity efforts interspersed with recovery periods. Due to high demands of handball performance, the use of ergogenic aids is a common ...strategy of handball players with the aim of enhancing handball performance, to allow more effective training, and to increase the rate of recovery. Although the use of ergogenic aids is generalized in the whole spectrum of competitive handball (e.g., from recreational to professional players), only a few ergogenic aids have been investigated to test their effectiveness to increase handball performance. In addition, no previous study has summarized the scientific literature on this topic to determine the ergogenic aids with good level of evidence regarding their effectiveness to increase handball physical performance. Thus, the aim of this narrative review was to describe the prevalence in the use of ergogenic aids in handball players and to analyse this information to identify which of these substances may increase physical performance in an intermittent sport such as competitive handball.
Nutritional supplements and ergogenic aids (NS&EA) are used between training/matches with the goal of enhancing tennis performance. Scientific literature about prevalence and use of NS&EA in ...professional tennis players is scarce.
The aim of the study was to describe the NS&EA used by professional tennis players during a season.
Using a validated self-administered questionnaire, 62 professional male and 9 professional female tennis players (11% in their gender specific top 100 tennis world ranking (i.e.,ATP/WTA)) registered all the used NS&EA.
Eighty-one percent of the participants declared taking at least one NS&EA. Strength and conditioning trainers (S&C) and tennis coaches were the professionals who recommended most of the NS&EA in the players outside the TOP-100 (OT100; 50.7% and 39.1%, respectively). However, sports nutritionist were the principal advisors in the top-100 tennis players (T100; 62.5%). Sports drinks were the NS&EA most commonly used by all participants (81.7%). T100 participants used caffeine (p = 0.042), creatine (p = 0.001), iron (p = 0.013) and CHO-protein mix (p = 0.033) significantly more frequently that OT100 players.
There is a high prevalence of NS&EA use among professional tennis players independently of their tennis ranking position. However, T100 tennis player have an increased use of certain substances such us caffeine, creatine, iron and CHO-Protein mix. For the rest of the studied NS&EA the use was similar between T100 and OT100 players. It is possible that the differences in NS&EA use between groups could be related to the different professionals on charge of nutritional advice in T100 vs OT100.
BackgroundTrastuzumab containing regimens are the standard of care for HER2+ breast cancer. While intravenous trastuzumab (Tiv) is administered as a weight based dose using an initial 90 min infusion ...followed by a subsequent 30 min infusion, subcutaneous trastuzumab (Tsc) is administered as a fixed 600 mg dose over 5 min without compromising its efficacy and safety. Potential savings associated with Tsc include loading dose avoidance and time reductions related to preparation and administration tasks.PurposeTo evaluate the impact on drug costs, patient chair time and safety profile of switching from the intravenous to the subcutaneous formulation of trastuzumabMaterial and methodsA retrospective study of all patients with HER2+ breast cancer who received trastuzumab from March 2015 to March 2016 in our hospital was conducted. Data collected were: age, body weight, route of administration, number of cycles and dose per cycle. Costs were calculated based on the use of vials and the trastuzumab posology (Tsc fixed dose 600 mg; Tiv 1 loading dose (8 mg/kg) plus maintenance cycles (6 mg/kg). Patient time in the infusion chair was considered 5 min for Tsc and 90 min for a loading dose of Tiv and 30 min for a maintenance dose of Tiv.Results74 patients were included: 44 were switched from Tiv to Tsc, and 30 started with Tsc. Median age was 60 years (35–87) and median body weight was 63 kg (42–103). Patients received a median of 10 cycles (1–18) and 378 mg (252–618) per cycle. Subcutaneous administration was cheaper above 63 kg in body weight. In spite of having patients with a median body weight of 63 kg, the savings generated by the change in administration to subcutaneous were €39 836. This was due to the difference in dosification between both treatment options. Tsc administration led to a six-fold reduction in patient chair time (447 hours). Tsc was well tolerated. Only in 1 patient was switching to the Tiv formulation necessary because of pain at the site of administration after two treatment cycles.ConclusionSwitching from Tiv to Tsc was associated with costs savings and reduced chair time, maintaining the safety of the treatment.References and/or acknowledgementsDe Cock E, et al. A time and motion study of subcutaneous versus intravenous trastuzumab in patients with HER2-positive early breast cancer. Can Med2016;5:389–97.No conflict of interest
BackgroundCancer patients are characterised by a high frequency of attendance at the emergency services. Specialised care is required due to complications from chemotherapy treatments. It is ...important that patients are educated about what to expect from their regimen and the correct use of supportive care medications.PurposeTo identify, quantify and analyse the reasons why cancer patients come to the emergency service, and to evaluate the toxicities related to chemotherapy.Material and methodsObservational and retrospective study including patients who attended in an emergency during 2014 and required the assistance of the oncologist. Data were collected from the PCH emergency programme and clinical documentation. Data analysed: age, sex, stage, histology, hospitalisation required, mean duration of hospitalisation and time between the last cycle of chemotherapy and the day attended the emergency service. The reasons for assistance were grouped into three types: tumour cause, chemotherapy toxicity and other.Results238 emergency events were analysed in 158 patients with a mean age of 65 ± 12.3 years. 58.2% (92) were men and 77.8% (123) were in stage IV. Regarding tumour histology, the majority were colorectal in 22.7% (36) of patients, and breast and lung in 20.8% (33). 50.8% (121) of events required hospitalisation with a mean duration of 11.4 days (1–24). The tumour cause was the reason for attendance by the oncologist in 47.4% (113) of events (including asthenia and dyspnoea). Chemotherapy toxicity was the reason in 36.9% (88) of cases. Of these, 47 were haematological disorders (15 with grade IV anaemia and 9 with grade IV neutropenia), 37 gastrointestinal disorders and 7 neurological disorders. The mean number of days between the last cycle of chemotherapy and the day attended the emergency service was 8.2 (1–24). 15.5% (37) of events were due to other reasons.ConclusionThe main reason why cancer patients come to the emergency service is related to the tumour process itself, followed by post-chemotherapy toxicities in 36.9% of events (mainly haematologic and gastrointestinal disorders). Pharmacists can educate patients about the adverse effects of chemotherapy and the ability to manage them. It would be interesting to develop models to predict the risk of post-chemotherapy toxicities in order to reduce these toxicities (and hospitalisations).No conflict of interest.
Grid-forming power converters are controlled as voltage sources to regulate the grid voltage and frequency. These converters can increase power system strength if they impose a voltage waveform ...resilient to grid transients. For this reason, in this paper, we propose a deadbeat control strategy of the capacitor voltage for high power converters with LCL filter. To damp the LCL resonant poles, an active damping strategy is developed, based on a modification of the deadbeat control law. With this purpose, a notch filter is applied to the electrical variables allowing to emulate different damping resistances for the fundamental component and the harmonics. As a result, the active damping does not introduce tracking errors of the fundamental frequency component, while it provides damping to the filter resonance. The proposed strategy does not require knowledge of the grid impedance, an interesting feature in grid-connected power converters because the grid impedance is generally unknown. Experimental results validate the proposed strategy.
Beetroot juice (BJ) is commonly used as an ergogenic aid in endurance and team sports, however, the effect of this supplement on climbing performance is barely studied. The purpose of the current ...study was to investigate the effect of acute BJ ingestion on neuromuscular and biochemical variables in amateur male sport climbers. Ten physically active sport climbers (28.8 ± 3.7 years) underwent a battery of neuromuscular tests consisting of the half crimp test, the pull-up to failure test, the isometric handgrip strength test, the countermovement jump (CMJ) and the squat jump (SJ). Participants performed the neuromuscular test battery twice in a cross-over design separated by 10 days, 150 min after having consumed either 70-mL of BJ (6.4 mmol NO
) or a 70-mL placebo (0.0034 mmol NO
). In addition, nitrate (NO
) and nitrite (NO
) saliva concentrations were analysed, and a side effect questionnaire related to ingestion was administrated. No differences were reported in particular neuromuscular variables measured such as the CMJ (p = 0.960; ES = 0.03), the SJ (p = 0.581; ES = -0.25), isometric handgrip strength (dominant/non dominant) (p = 0.459-0.447; ES = 0.34-0.35), the pull-up failure test (p = 0.272; ES = 0.51) or the maximal isometric half crimp test (p = 0.521-0.824; ES = 0.10-0.28). Salivary NO
and NO
increased significantly post BJ supplementation compared to the placebo (p < 0.001), while no side effects associated to ingestion were reported (p = 0.330-1.000) between conditions (BJ/placebo ingestion). Acute dietary nitrate supplementation (70-mL) did not produce any statistically significant improvement in neuromuscular performance or side effects in amateur sport climbers.
PDF
