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  • Author: Nathan A. Lewis x
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Nathan A. Lewis, Ann Redgrave, Mark Homer, Richard Burden, Wendy Martinson, Brian Moore and Charles R. Pedlar

Purpose: To examine a diagnosis of unexplained underperformance syndrome (UUPS, or overtraining syndrome) in an international rower describing a full recovery and return to elite competition the same year. Methods: On diagnosis and 4 and 14 mo postdiagnosis, detailed assessments including physiological, nutritional, and biomarkers were made. Results: Clinical examination and laboratory results for hematology, biochemistry, thyroid function, immunology, vitamins, and minerals were unremarkable and did not explain the presentation and diagnosis. Redox biomarkers including hydroperoxides, plasma antioxidant capacity, red blood cell glutathione, superoxide dismutase, coenzyme Q10, vitamin E (α- and γ-tocopherol), and carotenoids (lutein, α-carotene, β-carotene) provided evidence of altered redox homeostasis. The recovery strategy began with 12 d of training abstinence and nutritional interventions, followed by 6 wk of modified training. At 4 mo postintervention, performance had recovered strongly, resulting in the athlete’s becoming European champion that same year. Further improvements in physiological and performance indices were observed at 14 mo postintervention. Physiologically relevant increases in concentrations of carotenoids were achieved at each postintervention time point, exceeding the reported critical-difference values. Conclusions: Increasing athlete phytonutrient intake may enhance recovery and tolerance of training and environmental stressors, reducing the risk of unexplained UUPS. Alterations in redox homeostasis should be considered as part of the medical management in UUPS. This is the first reported case study of an elite athlete with alterations in redox homeostasis in conjunction with a diagnosis of UUPS.

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Alice M. Wallett, Amy L. Woods, Nathan Versey, Laura A. Garvican-Lewis, Marijke Welvaert and Kevin G. Thompson

Studies examining pacing strategies during 4000-m cycling time trials (TTs) typically ensure that participants are not prefatigued; however, competitive cyclists often undertake TTs when already fatigued. This study aimed to determine how TT pacing strategies and sprint characteristics of cyclists change during an intensified training period (mesocycle). Thirteen cyclists regularly competing in A- and B-grade cycling races and consistently training (>10 h/wk for 4 [1] y) completed a 6-wk training mesocycle. Participants undertook individually prescribed training, using training stress scores (TrainingPeaks, Boulder, CO), partitioned into a baseline week, a build week, 2 loading weeks (designed to elicit an overreached state), and 2 recovery weeks. Laboratory-based tests (15-s sprint and TT) and Recovery-Stress Questionnaire (RESTQ-52) responses were repeatedly undertaken over the mesocycle. TT power output increased during recovery compared with baseline and loading weeks (P = .001) with >6-W increases in mean power output (MPO) detected for 400-m sections (10% bins) from 1200 to 4000 m in recovery weeks. Decreases in peak heart rate (P < .001) during loading weeks and postexercise blood lactate (P = .005) during loading week 2 and recovery week 1 were detected. Compared with baseline, 15-s sprint MPO declined during loading and recovery weeks (P < .001). An interaction was observed between RESTQ-52 total stress score with a 15-s sprint (P = .003) and with a TT MPO (P = .04), indicating that participants who experienced greater stress during loading weeks exhibited reduced performance. To conclude, intensified endurance training diminished sprint performance but improved 4000-m TT performance, with a subtle change in MPO evident over the last 70% of TTs.

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Nathan A. Lewis, Andrew J. Simpkin, Sarah Moseley, Gareth Turner, Mark Homer, Ann Redgrave, Charles R. Pedlar and Richard Burden

Background: Identifying strategies that reduce the risk of illness and injury is an objective of sports science and medicine teams. No studies have examined the relationship between oxidative stress (OS) and illness or injury in international athletes undergoing periods of intensified training and competition. Purpose: The authors aimed to identify relationships between illness, injury, and OS. Methods: A longitudinal, observational study of elite male rowers (n = 10) was conducted over 18 weeks, leading into World Championships. Following a recovery day and a 12-hour fast, hydroperoxides (free oxygen radicals test) and total antioxidant capacity (free oxygen radicals defense) were measured in venous blood, with the ratio calculated as the oxidative stress index (OSI). At all study time points, athletes were independently dichotomized as ill or not ill, injured or not injured. OS data were compared between groups using independent t tests. A Cox proportional hazard model was used to assess the association of OS with injury and illness while adjusting for age and body mass index. Results: Free oxygen radicals defense was lower (P < .02) and OSI was higher (P < .001) with illness than without illness. Free oxygen radicals test and OSI were higher with injury than without injury (P < .001). A 0.5 mmol·L−1 increase in free oxygen radicals defense was associated with a 30.6% illness risk reduction (95% confidence interval, 7%–48%, P = .014), whereas 0.5 unit increase in OSI was related to a 11.3% increased illness risk (95% confidence interval, 1%–23%, P = .036). Conclusions: OS is increased in injured and ill athletes. Monitoring OS may be advantageous in assessing recovery from and in reducing injury and illness risk given the association.

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Rianne Costello, Mark E.T. Willems, Stephen D. Myers, Fiona Myers, Nathan A. Lewis, Ben J. Lee and Sam D. Blacker

New Zealand blackcurrant (NZBC) contains anthocyanins, known to moderate blood flow and display anti-inflammatory properties that may improve recovery from exercise-induced muscle damage. The authors examined whether NZBC extract supplementation enhances recovery from exercise-induced muscle damage after a half-marathon race. Following a randomized, double-blind, independent groups design, 20 (eight women) recreational runners (age 30 ± 6 years, height 1.73 ± 0.74 m, body mass 68.5 ± 7.8 kg, half-marathon finishing time 1:56:33 ± 0:18:08 hr:min:s) ingested either two 300-mg/day capsules of NZBC extract (CurraNZ) or a visually matched placebo, for 7 days prior to and 2 days following a half-marathon. Countermovement jump performance variables, urine interleukin-6, and perceived muscle soreness and fatigue were measured pre, post, and at 24 and 48 hr after the half-marathon and analyzed using a mixed linear model with statistical significance set a priori at p < .05. The countermovement jump performance variables were reduced immediately post-half-marathon (p < .05), with all returning to pre-half-marathon levels by 48 hr, except the concentric and eccentric peak force and eccentric duration, with no difference in response between groups (p > .05). Urine interleukin-6 increased 48-hr post-half-marathon in the NZBC group only (p < .01) and remained unchanged compared with pre-half-marathon levels in the placebo group (p > .05). Perceived muscle soreness and fatigue increased immediately post-half-marathon (p < .01) and returned to pre-half-marathon levels by 48 hr, with no difference between groups (p > .05). Supplementation with NZBC extract had no effect on the recovery of countermovement jump variables and perceptions of muscle soreness or fatigue following a half-marathon in recreational runners.