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1.
J Hum Kinet ; 91(Spec Issue): 157-164, 2024 Mar.
Article En | MEDLINE | ID: mdl-38689581

For the ischemic preconditioning (IPC) intervention, the accuracy of the protocol is paramount for mediating its possible ergogenic effects. However, the lack of standardization and widespread use of arbitrary cuff pressures (ranging from 130 to >300 mmHg) have been predominantly observed, potentially affecting the results and compromising the reproducibility of findings. Thus, the purpose of this study was to determine an appropriate cuff pressure during IPC. Seventeen healthy male participants were enrolled in the study. Anthropometric measurements were initially conducted, followed by systolic and diastolic blood pressure measurements. Subsequently, we determined the individual thigh occlusion pressure (TOP) for the right leg using a hand-held Doppler device. Based on these findings, we developed an estimation equation for TOP, considering the current brachial systolic blood pressure (SBP) values. We then conducted a retrospective analysis of its capacity to mediate occlusion. We observed the ability to estimate TOP using the equation (p = 0.01; ES: 0.86), presenting ~6% superiority in absolute values for occlusion compared to direct measurement (TOP equation: 169.9 ± 9.1; TOP direct measured: 161.2 ± 11.1). However, TOP estimation was insufficient to produce complete occlusion in two out of 17 subjects (11.8%). In conclusion, the estimation of TOP incorporating SBP values may offer a valid and practical means for cuff administration during IPC protocols with potential to minimize adverse effects and maximize its positive effects.

2.
Exp Physiol ; 109(5): 672-688, 2024 May.
Article En | MEDLINE | ID: mdl-38578259

This study compared the acute hypoalgesic and neurophysiological responses to low-load resistance exercise with and without blood flow restriction (BFR), and free-flow, high-load exercise. Participants performed four experimental conditions where they completed baseline measures of pain pressure threshold (PPT), maximum voluntary force (MVF) with peripheral nerve stimulation to determine central and peripheral fatigue. Corticospinal excitability (CSE), corticospinal inhibition and short interval intracortical inhibition (SICI) were estimated with transcranial magnetic stimulation. Participants then performed low-load leg press exercise at 30% of one-repetition maximum (LL); low-load leg press with BFR at 40% (BFR40) or 80% (BFR80) of limb occlusion pressure; or high-load leg press of four sets of 10 repetitions at 70% one-repetition maximum (HL). Measurements were repeated at 5, 45 min and 24 h post-exercise. There were no differences in CSE or SICI between conditions (all P > 0.05); however, corticospinal inhibition was reduced to a greater extent (11%-14%) in all low-load conditions compared to HL (P < 0.005). PPTs were 12%-16% greater at 5 min post-exercise in BFR40, BFR80 and HL compared to LL (P ≤ 0.016). Neuromuscular fatigue displayed no clear difference in the magnitude or time course between conditions (all P > 0.05). In summary, low-load BFR resistance exercise does not induce different acute neurophysiological responses to low-load, free-flow exercise but it does promote a greater degree of hypoalgesia and reduces corticospinal inhibition more than high-load exercise, making it a useful rehabilitation tool. The changes in neurophysiology following exercise were not related to changes in PPT.


Pain Threshold , Regional Blood Flow , Resistance Training , Transcranial Magnetic Stimulation , Humans , Male , Resistance Training/methods , Female , Adult , Transcranial Magnetic Stimulation/methods , Pain Threshold/physiology , Young Adult , Regional Blood Flow/physiology , Exercise/physiology , Muscle, Skeletal/physiology , Muscle Fatigue/physiology , Pyramidal Tracts/physiology , Evoked Potentials, Motor/physiology
3.
J Strength Cond Res ; 38(3): 481-490, 2024 Mar 01.
Article En | MEDLINE | ID: mdl-38088873

ABSTRACT: Scott, BR, Marston, KJ, Owens, J, Rolnick, N, and Patterson, SD. Current implementation and barriers to using blood flow restriction training: Insights from a survey of allied health practitioners. J Strength Cond Res 38(3): 481-490, 2024-This study investigated the use of blood flow restriction (BFR) exercise by practitioners working specifically with clinical or older populations, and the barriers preventing some practitioners from prescribing BFR. An online survey was disseminated globally to allied health practitioners, with data from 397 responders included in analyses. Responders who had prescribed BFR exercise ( n = 308) completed questions about how they implement this technique. Those who had not prescribed BFR exercise ( n = 89) provided information on barriers to using this technique, and a subset of these responders ( n = 22) completed a follow-up survey to investigate how these barriers could be alleviated. Most practitioners prescribe BFR exercise for musculoskeletal rehabilitation clients (91.6%), with the BFR cuff pressure typically relative to arterial occlusion pressure (81.1%) and implemented with resistance (96.8%) or aerobic exercise (42.9%). Most practitioners screen for contraindications (68.2%), although minor side effects, including muscle soreness (65.8%), are common. The main barriers preventing some practitioners from using BFR are lack of equipment (60.2%), insufficient education (55.7%), and safety concerns (31.8%). Suggestions to alleviate these barriers included developing educational resources about the safe application and benefits of BFR exercise ( n = 20) that are affordable ( n = 3) and convenient ( n = 4). These results indicate that BFR prescription for clinical and older cohorts mainly conforms with current guidelines, which is important considering the potentially increased risk for adverse events in these cohorts. However, barriers still prevent broader utility of BFR training, although some may be alleviated through well-developed educational offerings to train practitioners in using BFR exercise.


Muscle, Skeletal , Resistance Training , Humans , Muscle, Skeletal/physiology , Blood Flow Restriction Therapy , Resistance Training/methods , Myalgia , Exercise/physiology , Regional Blood Flow/physiology , Muscle Strength/physiology
4.
Eur J Sport Sci ; 23(12): 2435-2442, 2023 Dec.
Article En | MEDLINE | ID: mdl-37746841

Ischaemic preconditioning (IPC) applied locally and remotely has been shown to reduce pain which may underpin its ergogenic effect on exercise performance, however, it is unclear how many IPC cycles are needed to induce hypoalgesia. Therefore the purpose of this study was to examine the number of cycles of IPC on experimental pain perception. Sixteen healthy participants underwent four, randomised, experimental sessions where they either underwent a sham protocol (1 × 5 min at 20 mmHg), and 1, 2 or 3 cycles × 5 min of remote IPC at 105% of limb occlusion pressure. Ten minutes post-intervention, participants underwent a cold-pressor test where pain threshold, pain tolerance and pain intensity were examined and compared between conditions with a one-way repeated measure analysis of variance. Pain threshold was not different between conditions (P = 0.065); but pain tolerance was increased by ∼30% in the 1 × 5 condition, 2 × 5 condition, and 3 × 5 condition compared to the sham condition. No differences in pain tolerance were seen between the different numbers of cycles (all P > 0.05). There was also no difference in the perception of pain 30 s into the cold pressor test (P = 0.279). Remote IPC appears to significantly improve tolerance to pain which may have significant implications for endurance performance and exercise rehabilitation, but this warrants further investigation.


We found that one, two or three cycles of ischaemic preconditioning improved cold pain tolerance by 30% compared to a sham protocol, but there was no clear effect of IPC on pain threshold or pain intensity.The pain reported during IPC decreased from cycle one to cycle three in the three cycle condition, suggesting a potential conditioned pain modulation effect.An increase in pain tolerance may explain why IPC can improve exercise performance and IPC itself could be used as a tool to improve tolerance to pain.


Ischemic Preconditioning , Humans , Ischemic Preconditioning/methods , Exercise , Pain , Exercise Therapy , Extremities
5.
J Strength Cond Res ; 36(10): 2696-2700, 2022 Oct 01.
Article En | MEDLINE | ID: mdl-36135029

ABSTRACT: Lovegrove, S, Hughes, L, Mansfield, S, Read, P, Price, P, and Patterson, SD. Repetitions in reserve is a reliable tool for prescribing resistance training load. J Strength Cond Res 36(10): 2696-2700, 2022-This study investigated the reliability of repetitions in reserve (RIR) as a method for prescribing resistance training load for the deadlift and bench press exercises. Fifteen novice trained men (age: 17.3 ± 0.9 years, height: 176.0 ± 8.8 cm, body mass: 71.3 ± 10.7 kg) were assessed for 1 repetition maximum (1RM) for deadlift (118.1 ± 27.3 kg) and bench press (58.2 ± 18.6 kg). Subsequently, they completed 3 identical sessions (one familiarization session and 2 testing sessions) comprising sets of 3, 5, and 8 repetitions. For each repetition scheme, the load was progressively increased in successive sets until subjects felt they reached 1-RIR at the end of the set. Test-retest reliability of load prescription between the 2 testing sessions was determined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). A 2-way analysis of variance with repeated measures was used for each exercise to assess differences in the load corresponding to 1-RIR within each repetition scheme. All test-retest comparisons demonstrated a high level of reliability (deadlift: ICC = 0.95-0.99, CV = 2.7-5.7% and bench press: ICC = 0.97-0.99, CV = 3.8-6.2%). Although there were no differences between time points, there was a difference for load corresponding to 1-RIR across the 3 repetition schemes (deadlift: 88.2, 84.3, and 79.2% 1RM; bench press: 93.0, 87.3, and 79.6% 1RM for the 3-, 5-, and 8-repetition sets, respectively). These results suggest that RIR is a reliable tool for load prescription in a young novice population. Furthermore, the between-repetition scheme differences highlight that practitioners can effectively manipulate load and volume (repetitions in a set) throughout a training program to target specific resistance training adaptations.


Resistance Training , Adolescent , Exercise Test , Humans , Male , Muscle Strength , Reproducibility of Results , Resistance Training/methods , Weight Lifting
6.
J Clin Med ; 11(14)2022 Jul 06.
Article En | MEDLINE | ID: mdl-35887701

Muscle wasting is implicated in the pathogenesis of intensive care unit acquired weakness (ICU-AW), affecting 40% of patients and causing long-term physical disability. A repetitive vascular occlusion stimulus (RVOS) limits muscle atrophy in healthy and orthopaedic subjects, thus, we explored its application to ICU patients. Adult multi-organ failure patients received standard care +/- twice daily RVOS {4 cycles of 5 min tourniquet inflation to 50 mmHg supra-systolic blood pressure, and 5 min complete deflation} for 10 days. Serious adverse events (SAEs), tolerability, feasibility, acceptability, and exploratory outcomes of the rectus femoris cross-sectional area (RFCSA), echogenicity, clinical outcomes, and blood biomarkers were assessed. Only 12 of the intended 32 participants were recruited. RVOS sessions (76.1%) were delivered to five participants and two could not tolerate it. No SAEs occurred; 75% of participants and 82% of clinical staff strongly agreed or agreed that RVOS is an acceptable treatment. RFCSA fell significantly and echogenicity increased in controls (n = 5) and intervention subjects (n = 4). The intervention group was associated with less frequent acute kidney injury (AKI), a greater decrease in the total sequential organ failure assessment score (SOFA) score, and increased insulin-like growth factor-1 (IGF-1), and reduced syndecan-1, interleukin-4 (IL-4) and Tumor necrosis factor receptor type II (TNF-RII) levels. RVOS application appears safe and acceptable, but protocol modifications are required to improve tolerability and recruitment. There were signals of possible clinical benefit relating to RVOS application.

7.
Int J Sports Physiol Perform ; 17(9): 1425-1431, 2022 Sep 01.
Article En | MEDLINE | ID: mdl-35894997

PURPOSE: To examine the effect of fast- versus slow-speed eccentric-muscle-action resistance training on lower-body strength, vertical jump height, sprint speed, and change-of-direction performance in elite soccer players during a competitive season. METHODS: Twenty-two elite soccer players, from a single team, were randomly assigned to groups that undertook either 1- (fast speed) or 4-second (slow speed) eccentric resistance training during the in-season period. A 5-week program was conducted during an elite top-division European League soccer season. Performance measures including predicted 1-repetition-maximum back squat, countermovement jump, 20-m sprint, and change of direction were tested before and after the intervention period. Total match and training running distance and muscle soreness were also recorded during each week of the intervention. RESULTS: An analysis of covariance showed significant group effects (P = .01) for countermovement jump with a greater jump height in the 1-second fast-speed group postintervention (95% CI, 1.1-6.9 cm). Despite an overall increase in 1-repetition maximum pretraining to posttraining (95% CI, 10.0-15.3 kg, effect size 0.69), there were no significant differences (P > .05) between groups after the intervention. Similarly, there were no differences between groups for change of direction, 20-m sprint, or muscle soreness. CONCLUSION: Faster eccentric muscle actions may be superior for increasing movements in elite soccer players in-season.


Athletic Performance , Resistance Training , Running , Soccer , Athletic Performance/physiology , Humans , Muscle Strength/physiology , Muscles , Myalgia , Running/physiology , Seasons , Soccer/physiology
8.
Eur J Appl Physiol ; 122(8): 1797-1810, 2022 Aug.
Article En | MEDLINE | ID: mdl-35362800

Heat-induced hypo-hydration (hyperosmotic hypovolemia) can reduce prolonged skeletal muscle performance; however, the mechanisms are less well understood and the reported effects on all aspects of neuromuscular function and brief maximal contractions are inconsistent. Historically, a 4-6% reduction of body mass has not been considered to impair muscle function in humans, as determined by muscle torque, membrane excitability and peak power production. With the development of magnetic resonance imaging and neurophysiological techniques, such as electromyography, peripheral nerve, and transcranial magnetic stimulation (TMS), the integrity of the brain-to-muscle pathway can be further investigated. The findings of this review demonstrate that heat-induced hypo-hydration impairs neuromuscular function, particularly during repeated and sustained contractions. Additionally, the mechanisms are separate to those of hyperthermia-induced fatigue and are likely a result of modulations to corticospinal inhibition, increased fibre conduction velocity, pain perception and impaired contractile function. This review also sheds light on the view that hypo-hydration has 'no effect' on neuromuscular function during brief maximal voluntary contractions. It is hypothesised that irrespective of unchanged force, compensatory reductions in cortical inhibition are likely to occur, in the attempt of achieving adequate force production. Studies using single-pulse TMS have shown that hypo-hydration can reduce maximal isometric and eccentric force, despite a reduction in cortical inhibition, but the cause of this is currently unclear. Future work should investigate the intracortical inhibitory and excitatory pathways within the brain, to elucidate the role of the central nervous system in force output, following heat-induced hypo-hydration.


Evoked Potentials, Motor , Isometric Contraction , Electric Stimulation/methods , Electromyography/methods , Evoked Potentials, Motor/physiology , Hot Temperature , Humans , Isometric Contraction/physiology , Muscle Contraction/physiology , Muscle Fatigue/physiology , Muscle, Skeletal/physiology , Transcranial Magnetic Stimulation
9.
Clin J Sport Med ; 32(6): 580-587, 2022 11 01.
Article En | MEDLINE | ID: mdl-35325898

OBJECTIVE: There is a high incidence of concussion and frequent utilization of rapid weight loss (RWL) methods among combat sport athletes, yet the apparent similarity in symptoms experienced as a result of a concussion or RWL has not been investigated. This study surveyed combat sports athletes to investigate the differences in symptom onset and recovery between combat sports and evaluated the relationships between concussion and RWL symptoms. DESIGN: Cross-sectional study. SETTING: Data were collected through an online survey. PARTICIPANTS: One hundred thirty-two (115 male athletes and 17 female athletes) combat sport athletes. INTERVENTIONS: Modified Sport Concussion Assessment Tool (SCAT) symptom checklist and weight-cutting questionnaire. MAIN OUTCOME MEASURES: Survey items included combat sport discipline, weight loss, medical history, weight-cutting questionnaire, and concussion and weight-cutting symptom checklists. RESULTS: Strong associations ( rs = 0.6-0.7, P < 0.05) were observed between concussion and RWL symptoms. The most frequently reported symptom resolution times were 24 to 48 hours for a weight cut (WC; 59%) and 3 to 5 days for a concussion (43%), with 60% to 70% of athletes reporting a deterioration and lengthening of concussion symptoms when undergoing a WC. Most of the athletes (65%) also reported at least one WC in their career to " not go according to plan ," resulting in a lack of energy (83%) and strength/power (70%). CONCLUSIONS: Rapid weight loss and concussion symptoms are strongly associated, with most of the athletes reporting a deterioration of concussion symptoms during a WC. The results indicate that concussion symptoms should be monitored alongside hydration status to avoid any compound effects of prior RWL on the interpretation of concussion assessments and to avoid potential misdiagnoses among combat athletes.


Athletic Injuries , Brain Concussion , Male , Female , Humans , Cross-Sectional Studies , Brain Concussion/diagnosis , Brain Concussion/etiology , Athletes , Weight Loss , Surveys and Questionnaires , Athletic Injuries/diagnosis , Athletic Injuries/complications
10.
Aerosp Med Hum Perform ; 93(1): 32-45, 2022 Jan 01.
Article En | MEDLINE | ID: mdl-35063054

INTRODUCTION: During spaceflight missions, astronauts work in an extreme environment with several hazards to physical health and performance. Exposure to microgravity results in remarkable deconditioning of several physiological systems, leading to impaired physical condition and human performance, posing a major risk to overall mission success and crew safety. Physical exercise is the cornerstone of strategies to mitigate physical deconditioning during spaceflight. Decades of research have enabled development of more optimal exercise strategies and equipment onboard the International Space Station. However, the effects of microgravity cannot be completely ameliorated with current exercise countermeasures. Moreover, future spaceflight missions deeper into space require a new generation of spacecraft, which will place yet more constraints on the use of exercise by limiting the amount, size, and weight of exercise equipment and the time available for exercise. Space agencies are exploring ways to optimize exercise countermeasures for spaceflight, specifically exercise strategies that are more efficient, require less equipment, and are less time-consuming. Blood flow restriction exercise is a low intensity exercise strategy that requires minimal equipment and can elicit positive training benefits across multiple physiological systems. This method of exercise training has potential as a strategy to optimize exercise countermeasures during spaceflight and reconditioning in terrestrial and partial gravity environments. The possible applications of blood flow restriction exercise during spaceflight are discussed herein.Hughes L, Hackney KJ, Patterson SD. Optimization of exercise countermeasures to spaceflight using blood flow restriction. Aerosp Med Hum Perform. 2021; 93(1):32-45.


Space Flight , Weightlessness , Astronauts , Blood Flow Restriction Therapy , Exercise , Humans
12.
J Sci Med Sport ; 24(7): 709-714, 2021 Jul.
Article En | MEDLINE | ID: mdl-33648866

OBJECTIVES: The aim of this investigation was to determine if acute or repeated applications of ischemic preconditioning (IPC) could enhance the recovery process, following exercise induced muscle damage (EIMD). DESIGN: Randomized control trial. METHODS: Twenty-three healthy males were familiarised with the muscle damaging protocol (five sets of 20 drop jumps from a 0.6 m box) and randomly allocated to one of three groups: SHAM (3 × 5 min at 20 mmHg), Acute IPC (3 × 5 min at 220 mmHg) and Repeated IPC (3 days x 3 × 5 min at 220 mmHg). The indices of muscle damage measured included creatine kinase concentration ([CK]), thigh swelling, delayed onset muscle soreness, counter movement jumps (CMJ) and maximal voluntary isometric contraction (MVIC). RESULTS: Both acute and repeated IPC improved recovery in MVIC versus SHAM. Repeated IPC led to a faster MVIC recovery at 48 h (101.5%) relative to acute IPC (92.6%) and SHAM (84.4%) (P <  0.05). Less swelling was found for both acute and repeated IPC vs. SHAM (P <  0.05) but no group effects were found for CMJ, soreness or [CK] responses (P >  0.05). CONCLUSION: Taken together, repeated IPC can enhance recovery time of MVIC more than an acute application, and both reduce swelling following EIMD, relative to a SHAM condition.


Exercise/physiology , Ischemic Preconditioning , Muscle, Skeletal/blood supply , Muscle, Skeletal/injuries , Adult , Competitive Behavior/physiology , Creatine Kinase/blood , Edema/diagnosis , Edema/prevention & control , Humans , Isometric Contraction , Male , Muscle Strength , Muscle, Skeletal/pathology , Myalgia/diagnosis , Myalgia/prevention & control , Recovery of Function , Regional Blood Flow , Young Adult
13.
Int J Sports Med ; 42(10): 911-916, 2021 Sep.
Article En | MEDLINE | ID: mdl-33601423

Explosive actions are integral to soccer performance and highly influenced by the ability to generate maximal power. The purpose of this study was to investigate the relationship between force-velocity profile, jump performance, acceleration and maximal sprint speed in elite female soccer players. Thirty-nine international female soccer players (24.3±4.7 years) performed 40-m sprints, maximal countermovement jumps and five loaded squat jumps at increasing loads to determine individual force-velocity profiles. Theoretical maximal velocity, theoretical maximal force, maximal power output, one repetition maximal back squat and one repetition maximal back squat relative to body mass were determined using the force-velocity profile. Counter movement jump, squat jump and maximal power output demonstrated moderate to large correlation with acceleration and maximal sprint speed (r=- 0.32 to -0.44 and -0.32 to -0.67 respectively, p<0.05). Theoretical maximal velocity and force, one repetition maximal and relative back squat demonstrated a trivial to small relationship to acceleration and maximal sprint speed (p>0.05). Vertical force-velocity profiling and maximal strength can provide valuable insight into the neuromuscular qualities of an athlete to individualize training, but the ability to produce force, maximal power, and further transference into sprint performance, must be central to program design.


Athletic Performance/physiology , Running/physiology , Soccer/physiology , Acceleration , Adult , Athletes , Female , Humans , Muscle Strength , Muscle, Skeletal/physiology , Young Adult
14.
J Strength Cond Res ; 35(10): 2833-2838, 2021 Oct 01.
Article En | MEDLINE | ID: mdl-31145382

ABSTRACT: Waddingham, DP, Millyard, A, Patterson, SD, and Hill, J. Effect of ballistic potentiation protocols on elite sprint swimming: optimizing performance. J Strength Cond Res 35(10): 2833-2838, 2021-Warming-up before an athletic event is important for performance; however, in some competition scenarios, there is a long wait between completing the warm-up and the event. Thus, potentiation protocols are becoming increasingly popular in a competition environment. The aim of the study was to determine the effects of practical potentiation protocols on 15-m start performance in national level swimmers. Eleven national level swimmers participated in the study. Using a randomized cross-over design, subjects completed a 15-m swimming start following 4 different experimental conditions (swim-specific control, resisted band squat, weighted countermovement jumps, and drop jumps from a 45-cm box), each separated by at least 48 hours. A repeated-measures analysis of variance showed a significant difference in 15-m swimming start performance following different warm-up protocols (F(1.646, 14.810) = 6.968, p = 0.01). A post hoc Bonferroni test indicated that 15-m start time was significantly quicker with the band squat protocol compared with the swim-specific protocol (6.65 ± 0.43 vs. 6.78 ± 0.43 seconds, respectively, p = 0.04). The results conclude that practical potentiation protocols are able to enhance 15-m swim start performance when combined with a swim-specific warm-up and supports the use of postactivation potentiation during competitive swimming environments.


Athletic Performance , Warm-Up Exercise , Cross-Over Studies , Humans , Swimming
15.
J Strength Cond Res ; 35(10): 2790-2794, 2021 Oct 01.
Article En | MEDLINE | ID: mdl-31269000

ABSTRACT: Jeffries, O, Simmons, R, Patterson, SD, and Waldron, M. Functional threshold power is not equivalent to lactate parameters in trained cyclists. J Strength Cond Res 35(10): 2790-2794, 2021-Functional threshold power (FTP) is derived from a maximal self-paced 20-minute cycling time trial whereby the average power output is scaled by 95%. However, the physiological basis of the FTP concept is unclear. Therefore, we evaluated the relationship of FTP with a range of laboratory-based blood lactate parameters derived from a submaximal threshold test. Twenty competitive male cyclists completed a maximal 20-minute time trial and an incremental exercise test to establish a range of blood lactate parameters. Functional threshold power (266 ± 42 W) was strongly correlated (r = 0.88, p < 0.001) with the power output associated with a fixed blood lactate concentration 4.0 mmol·L-1 (LT4.0) (268 ± 30 W) and not significantly different (p > 0.05). While mean bias was 2.9 ± 24.6 W, there were large limits of agreement (LOA) between FTP and LT4.0 (-45 to 51 W). All other lactate parameters, lactate threshold (LT) (236 ± 32 W), individual anaerobic threshold (244 ± 33 W), and LT thresholds determined using the Dmax method (221 ± 25 W) and modified Dmax method (238 ± 32 W) were significantly different from FTP (p < 0.05). While FTP strongly correlated with LT4.0, the large LOA refutes any equivalence as a measure with physiological basis. Therefore, we would encourage athletes and coaches to use alternative field-based methods to predict cycling performance.


Bicycling , Lactic Acid , Anaerobic Threshold , Exercise Test , Humans , Male , Oxygen Consumption
17.
J Strength Cond Res ; 34(12): 3475-3481, 2020 Dec.
Article En | MEDLINE | ID: mdl-29065052

Jeffries, O, Hill, J, Patterson, SD, and Waldron, M. Energy drink doses of caffeine and taurine have a null or negative effect on sprint performance. J Strength Cond Res 34(12): 3475-3481, 2020-This study investigated the effects of caffeine and taurine coingestion on repeat-sprint cycling performance and associated physiological and perceptual responses. In a double-blind, cross-over, repeated measures study, 11 male subjects (age 21 ± 2 years; stature 178 ± 7 cm; body mass 80 ± 13 kg) completed 10 × 6-second sprints on a cycle ergometer, each separated by 24 seconds, one hour after ingesting: caffeine (80 mg) and taurine (1 g), equivalent to the amount observed in popular commercial energy drinks, or placebo (maltodextrin ∼1 g) in a gelatine capsule. Performance was measured on a cycle ergometer, whereas blood lactate concentration (B[la]), rating of perceived exertion (RPE), and heart rate (HR) were measured at baseline (pre-exercise) and after sprints 5 and 10. Magnitude-based inferences revealed likely, trivial differences in peak power and unclear, trivial intersprint fatigue index after ingestion of the caffeine and taurine supplement. Intrasprint fatigue was greater in the caffeine and taurine condition at sprint 10 (likely, small) and possibly smaller in sprints 6-9. The caffeine and taurine supplement had a likely large effect on HR at baseline (effect size = 0.94) and increases in B[la] after sprints 5 (likely small) and 10 (possibly small). There was no effect of the supplement on RPE (unclear, trivial). Administration of caffeine and taurine at doses equivalent to commercial energy drinks did not improve repeat-sprint cycling performance and seemed to induce greater fatigue within selected sprints, particularly at the end of the trial. This undesirable performance effect occurs in parallel with increased HR and glycolytic metabolic bi-products.


Athletic Performance , Energy Drinks , Running , Adult , Caffeine , Cross-Over Studies , Double-Blind Method , Ergometry , Humans , Male , Taurine/pharmacology , Young Adult
19.
Front Physiol ; 10: 1239, 2019.
Article En | MEDLINE | ID: mdl-31636569

This study systematically reviewed the available scientific evidence pertaining to the acute and chronic changes promoted by aerobic exercise (AE) combined with blood flow restriction (BFR) on neuromuscular, metabolic and hemodynamic variables. PubMed, Web of ScienceTM and Scopus databases were searched for the period from January 2000 to June 2019 and the analysis involved a critical content review. A total of 313 articles were identified, of which 271 were excluded and 35 satisfied the inclusion criteria. Twelve studies evaluated the acute effects and eight studies evaluated the chronic metabolic effects of AE + BFR. For the neuromuscular variables, three studies analyzed the acute effects of AE + BFR and nine studies analyzed the chronic effects. Only 15 studies were identified that evaluated the hemodynamic acute effects of AE + BFR. The analysis provided evidence that AE combined with BFR promotes positive acute and chronic changes in neuromuscular and metabolic variables, a greater elevation in hemodynamic variables than exercise alone, and a higher energy demand during and after exercise. Since these alterations were all well-tolerated, this method can be considered to be safe and feasible for populations of athletes, healthy young, obese, and elderly individuals.

20.
Eur J Appl Physiol ; 119(10): 2123-2149, 2019 Oct.
Article En | MEDLINE | ID: mdl-31451953

Ischemic preconditioning (IPC) has been suggested as a potential ergogenic aid to improve exercise performance, although controversial findings exist. The controversies may be explained by several factors, including the mode of exercise, the ratio between the magnitude of improvement, or the error of measurement and physiological meaning. However, a relevant aspect has been lacking in the literature: the interpretation of the findings considering statistical tests and adequate effect size (ES) according to the fitness level of individuals. Thus, we performed a systematic review with meta-analysis to update the effects of IPC on exercise performance and physiological responses, using traditional statistics (P values), ES, and smallest worth change (SWC) approach contextualizing the IPC application to applied Sports and Exercise performance. Forty-five studies met the inclusion criteria. Overall, the results show that IPC has a minimal or nonsignificant effect on performance considering the fitness level of the individuals, using statistical approaches (i.e., tests with P value, ES, and SWC). Therefore, IPC procedures should be revised and refined in future studies to evaluate if IPC promotes positive effects on performance in a real-world scenario with more consistent interpretation.


Ischemic Preconditioning/methods , Physical Conditioning, Human/methods , Exercise Tolerance , Humans , Ischemic Preconditioning/adverse effects , Oxygen Consumption , Physical Conditioning, Human/adverse effects , Physical Fitness
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