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- Title
Impact of intensified training and carbohydrate supplementation on immunity and markers of overreaching in highly trained cyclists.
- Authors
Svendsen, Ida; Killer, Sophie; Carter, James; Randell, Rebecca; Jeukendrup, Asker; Gleeson, Michael; Svendsen, Ida S; Killer, Sophie C; Carter, James M; Randell, Rebecca K; Jeukendrup, Asker E
- Abstract
<bold>Purpose: </bold>To determine effects of intensified training (IT) and carbohydrate supplementation on overreaching and immunity.<bold>Methods: </bold>In a randomized, double-blind, crossover design, 13 male cyclists (age 25 ± 6 years, VO2max 72 ± 5 ml/kg/min) completed two 8-day periods of IT. On one occasion, participants ingested 2 % carbohydrate (L-CHO) beverages before, during and after training sessions. On the second occasion, 6 % carbohydrate (H-CHO) solutions were ingested before, during and after training, with the addition of 20 g of protein in the post-exercise beverage. Blood samples were collected before and immediately after incremental exercise to fatigue on days 1 and 9.<bold>Results: </bold>In both trials, IT resulted in decreased peak power (375 ± 37 vs. 391 ± 37 W, P < 0.001), maximal heart rate (179 ± 8 vs. 190 ± 10 bpm, P < 0.001) and haematocrit (39 ± 2 vs. 42 ± 2 %, P < 0.001), and increased plasma volume (P < 0.001). Resting plasma cortisol increased while plasma ACTH decreased following IT (P < 0.05), with no between-trial differences. Following IT, antigen-stimulated whole blood culture production of IL-1α was higher in L-CHO than H-CHO (0.70 (95 % CI 0.52-0.95) pg/ml versus 0.33 (0.24-0.45) pg/ml, P < 0.01), as was production of IL-1β (9.3 (95 % CI 7-10.4) pg/ml versus 6.0 (5.0-7.8) pg/ml, P < 0.05). Circulating total leukocytes (P < 0.05) and neutrophils (P < 0.01) at rest increased following IT, as did neutrophil:lymphocyte ratio and percentage CD4+ lymphocytes (P < 0.05), with no between-trial differences.<bold>Conclusion: </bold>IT resulted in symptoms consistent with overreaching, although immunological changes were modest. Higher carbohydrate intake was not able to alleviate physiological/immunological disturbances.
- Subjects
CYCLISTS; RESISTANCE training; PHYSICAL training & conditioning; PHYSICAL activity; IMMUNITY; ADRENOCORTICOTROPIC hormone; COMPARATIVE studies; CROSSOVER trials; CYCLING; DIETARY supplements; EXERCISE; FATIGUE (Physiology); CARBOHYDRATE content of food; HYDROCORTISONE; INTERLEUKIN-1; RESEARCH methodology; MEDICAL cooperation; PHYSICAL fitness; RESEARCH; T cells; EVALUATION research; RANDOMIZED controlled trials; BLIND experiment
- Publication
European Journal of Applied Physiology, 2016, Vol 116, Issue 5, p867
- ISSN
1439-6319
- Publication type
Academic Journal
- DOI
10.1007/s00421-016-3340-z