ORCID Profile
0000-0002-5086-6350
Current Organisation
Northumbria University
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Publisher: Wiley
Date: 12-07-2021
DOI: 10.1111/SMS.14004
Abstract: The etiology of changes in lower‐limb neuromuscular function, especially to the central nervous system, may be affected by exercise duration. Direct evidence is lacking as few studies have directly compared different race distances. This study aimed to investigate the etiology of deficits in neuromuscular function following short versus long trail‐running races. Thirty‐two male trail runners completed one of five trail‐running races as LONG ( km) or SHORT ( km). Pre‐ and post‐race, maximal voluntary contraction (MVC) torque and evoked responses to electrical nerve stimulation during MVCs and at rest were used to assess voluntary activation and muscle contractile properties of knee‐extensor (KE) and plantar‐flexor (PF) muscles. Transcranial magnetic stimulation (TMS) was used to assess evoked responses and corticospinal excitability in maximal and submaximal KE contractions. Race distance correlated with KE MVC ( ρ = −0.556) and twitch ( ρ = −0.521) torque decreases ( p ≤ .003). KE twitch torque decreased more in LONG (−28 ± 14%) than SHORT (−14 ± 10%, p = .005) however, KE MVC time × distance interaction was not significant ( p = .073). No differences between LONG and SHORT for PF MVC or twitch torque were observed. Maximal voluntary activation decreased similarly in LONG and SHORT in both muscle groups ( p ≥ .637). TMS‐elicited silent period decreased in LONG ( p = .021) but not SHORT ( p = .912). Greater muscle contractile property impairment in longer races, not central perturbations, contributed to the correlation between KE MVC loss and race distance. Conversely, PF fatigability was unaffected by race distance.
Publisher: American Physiological Society
Date: 15-05-2015
Publisher: Springer Science and Business Media LLC
Date: 17-09-2010
DOI: 10.1007/S00421-009-1185-4
Abstract: Carbohydrate ingestion during exercise and as a pre-exercise bolus improves exercise performance in able-bodied athletes. Little is known about the potential for carbohydrate ingestion to improve exercise performance in athletes with spinal cord injury (SCI), nor the potential physiological limitations of such a practice resulting from an SCI. Therefore, this study investigated the effects of carbohydrate ingestion on exercise performance in physically active and athletic persons with SCI. Six participants with complete SCI (neurological level of lesion ranging from C(6) to T(7)) and normal glucose tolerance were studied twice during 60 min of arm cranking at 65% of peak oxygen consumption followed by a 20-min time trial with the ingestion of either a carbohydrate drink (CHO trial: 0.5 g CHO kg(-1) body weight in 500 ml) or placebo (PLA trial) applied in a double-blind counter-balanced manner. The participants with tetraplegia had sufficient neurological function to permit voluntary arm-cranking exercise. There was no difference in time-trial performance between CHO and PLA trials (P > 0.05). The results suggest that carbohydrate ingestion in persons with SCI does not improve exercise performance.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-06-2021
DOI: 10.1249/MSS.0000000000002719
Abstract: Women have been shown to experience less neuromuscular fatigue than men in knee extensors (KE) and less peripheral fatigue in plantar flexors (PF) after ultratrail running, but it is unknown if these differences exist for shorter trail running races and whether this may impact running economy. The purpose of this study was to characterize sex differences in fatigability over a range of running distances and to examine possible differences in the postrace alteration of the cost of running (Cr). Eighteen pairs of men and women were matched by performance after completing different races ranging from 40 to 171 km, ided into SHORT versus LONG races ( and km, respectively). Neuromuscular function and Cr were tested before and after each race. Neuromuscular function was evaluated on both KE and PF with voluntary and evoked contractions using electrical nerve (KE and PF) and transcranial magnetic (KE) stimulation. Oxygen uptake, respiratory exchange ratio, and ventilation were measured on a treadmill and used to calculate Cr. Compared with men, women displayed a smaller decrease in maximal strength in KE (−36% vs −27%, respectively, P 0.01), independent of race distance. In SHORT only, women displayed less peripheral fatigue in PF compared with men (Δ peak twitch: −10% vs −24%, respectively, P 0.05). Cr increased similarly in men and women. Women experience less neuromuscular fatigue than men after both “classic” and “extreme” prolonged running exercises but this does not impact the degradation of the energy Cr.
Publisher: Elsevier BV
Date: 05-2011
Abstract: This study was a systematic review with meta-analysis examining the efficacy of carbohydrate (CHO) ingestion compared with placebo (PLA) on endurance exercise performance in adults. Relevant databases were searched to January 2011. Included studies were PLA-controlled, randomized, crossover designs in which CHO ingestion not exceeding 8% and between 30 and 80 g/h during exercise of ≥1 h was evaluated via time trial (TT) or exercise time to exhaustion (TTE). The between-trial standardized mean differences [effect size (ES)] and pooled estimates of the effect of CHO ingestion were calculated. Of the 41,175 studies from the initial search, 50 were included. The ES for submaximal exercise followed by TT was significant (ES = 0.53 95% CI = 0.37-0.69 P < 0.001) as was the ES for TT (ES = 0.30 95% CI = 0.07-0.53 P = 0.011). The weighted mean improvement in exercise performance favored CHO ingestion (7.5 and 2.0%, respectively). TTE (ES = 0.47 95% CI = 0.32-0.62 P < 0.001) and submaximal exercise followed by TTE (ES = 0.44 95% CI = 0.08-0.80 P = 0.017) also showed significant effects, with weighted mean improvements of 15.1 and 54.2%, respectively, with CHO ingestion. Similar trends were evident for subanalyses of studies using only male or trained participants, for exercise of 1-3 h duration, and where CHO and PLA beverages were matched for electrolyte content. The data support that ingestion of CHO between 30 and 80 g/h enhances endurance exercise performance in adults.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for John Temesi.