PMID- 34690285
OWN - NLM
STAT- MEDLINE
DCOM- 20220307
LR  - 20230410
IS  - 1530-0315 (Electronic)
IS  - 0195-9131 (Linking)
VI  - 54
IP  - 3
DP  - 2022 Mar 1
TI  - Six Days of Low Carbohydrate, Not Energy Availability, Alters the Iron and Immune 
      Response to Exercise in Elite Athletes.
PG  - 377-387
LID - 10.1249/MSS.0000000000002819 [doi]
AB  - PURPOSE: To quantify the effects of a short-term (6-d) low carbohydrate (CHO) 
      high fat (LCHF), and low energy availability (LEA) diet on immune, inflammatory, 
      and iron-regulatory responses to exercise in endurance athletes. METHODS: 
      Twenty-eight elite male race walkers completed two 6-d diet/training phases. 
      During phase 1 (Baseline), all athletes consumed a high CHO/energy availability 
      (CON) diet (65% CHO and ~40 kcal.kg-1 fat-free mass (FFM).d-1). In phase 2 
      (Adaptation), athletes were allocated to either a CON (n = 10), LCHF (n = 8; <50 
      g.d-1 CHO and ~40 kcal.kg-1.FFM-1.d-1), or LEA diet (n = 10; 60% CHO and 15 
      kcal.kg-1.FFM-1.d-1). At the end of each phase, athletes completed a 25-km race 
      walk protocol at ~75% V O2max. On each occasion, venous blood was collected 
      before and after exercise for interleukin-6, hepcidin, cortisol, and glucose 
      concentrations, as well as white blood cell counts. RESULTS: The LCHF athletes 
      displayed a greater IL-6 (P = 0.019) and hepcidin (P = 0.011) response to 
      exercise after Adaptation, compared with Baseline. Similarly, postexercise 
      increases in total white blood cell counts (P = 0.026) and cortisol levels (P < 
      0.001) were larger compared with Baseline after LCHF Adaptation. Decreases in 
      blood glucose concentrations were evident postexercise during Adaptation in LCHF 
      (P = 0.049), whereas no change occurred in CON or LEA (P > 0.05). No differences 
      between CON and LEA were evident for any of the measured biological markers (all 
      P > 0.05). CONCLUSIONS: Short-term adherence to a LCHF diet elicited small yet 
      unfavorable iron, immune, and stress responses to exercise. In contrast, no 
      substantial alterations to athlete health were observed when athletes restricted 
      energy availability compared with athletes with adequate energy availability. 
      Therefore, short-term restriction of CHO, rather than energy, may have greater 
      negative impacts on athlete health.
CI  - Copyright (c) 2021 by the American College of Sports Medicine.
FAU - McKay, Alannah K A
AU  - McKay AKA
FAU - Peeling, Peter
AU  - Peeling P
FAU - Pyne, David B
AU  - Pyne DB
AD  - Research Institute for Sport and Exercise, University of Canberra, Canberra, 
      AUSTRALIA.
FAU - Tee, Nicolin
AU  - Tee N
AD  - Mary MacKillop Institute for Health Research, Australian Catholic University, 
      Melbourne, AUSTRALIA.
FAU - Whitfield, Jamie
AU  - Whitfield J
AD  - Mary MacKillop Institute for Health Research, Australian Catholic University, 
      Melbourne, AUSTRALIA.
FAU - Sharma, Avish P
AU  - Sharma AP
AD  - Triathlon Australia, Burleigh Heads, AUSTRALIA.
FAU - Heikura, Ida A
AU  - Heikura IA
FAU - Burke, Louise M
AU  - Burke LM
AD  - Mary MacKillop Institute for Health Research, Australian Catholic University, 
      Melbourne, AUSTRALIA.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - 0 (Biomarkers)
RN  - E1UOL152H7 (Iron)
SB  - IM
MH  - Adult
MH  - *Athletes
MH  - Athletic Performance/*physiology
MH  - Biomarkers/blood
MH  - Diet, Ketogenic/*methods
MH  - Humans
MH  - Immunity/*physiology
MH  - Iron/*metabolism
MH  - Male
MH  - Walking/*physiology
MH  - Young Adult
EDAT- 2021/10/26 06:00
MHDA- 2022/03/08 06:00
CRDT- 2021/10/25 06:14
PHST- 2021/10/26 06:00 [pubmed]
PHST- 2022/03/08 06:00 [medline]
PHST- 2021/10/25 06:14 [entrez]
AID - 00005768-202203000-00002 [pii]
AID - 10.1249/MSS.0000000000002819 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 2022 Mar 1;54(3):377-387. doi: 
      10.1249/MSS.0000000000002819.