Inducing low energy availability in trained endurance male athletes results in poorer explosive power

Abstract

Purpose Low energy availability in males needs more original research to understand its health and performance consequences. The aim of the study was to induce low energy availability in previously healthy male endurance athletes by reducing energy availability by 25% for 14 consecutive days and measure any potential changes in performance, health, mental state or energy markers. Methods Energy availability was reduced in 12 trained, well-trained and elite endurance athletes by increasing energy expenditure and controlling energy intake. After intervention, health was assessed by blood draw, body composition was measured, energy markers by measuring resting energy expenditure, performance with three specific tests (measuring endurance, agility and explosive power) and two questionnaires were used for psychological assessment (the Three Factor Eating Questionnaire and Well-being questionnaire). Results Reduced energy availability (22.4 ± 6.3 kcal/kg FFM/day) caused significantly lower haemoglobin values (t(12) = 2.652, p = 0.022), there was a tendency for lower iron and IGF-1 (p = 0.066 and p = 0.077, respectively). Explosive power was reduced (t(12) = 4.570, p = 0.001), lactate metabolism was altered and athletes reported poorer well-being (t(12) = 2.385, p = 0.036). Cognitive restriction was correlated with energy availability (r = 0.528, p = 0.039). Conclusion This is the first research providing direct evidence that suboptimal energy availability negatively impacts explosive power before hormonal changes occur in male endurance athletes. It is also the first to show direct association of low energy availability and higher cognitive restriction. We also observed worse well-being and lower haemoglobin values. 25% of energy availability reduction as not enough to elicit changes in resting energy expenditure.

2023 International Olympic Committee’s (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs)

“…Psychological indicators associated with problematic LEA and REDs are mood disturbances/fluctuations,8 71 72 cognitive dietary restraint,73 drive for thinness,74 75 reduced sleep quality50 76 and perfectionistic tendencies 77. Depressive symptoms and affective disorders,8 78 79 subjectively reported reduced well-being,73 primary or secondary exercise dependence/addiction,80 81 anxiety related to injury and/or recovery, sport-specific issues such as difficulty coping with weight requirements67 76 and the development of EDs1 82 are additional adverse mental health outcomes associated with problematic LEA and REDs. However, we must recognise that the picture is still unclear regarding the dynamics of mental health and DE behaviours according to sex and level of competition,83 as well as in athletes with physical disabilities 84.…”

Energy availability and RED-S risk assessment among Kho-Kho players in India

“…However, there were no such differences in other performance parameters related to power and speed in this study. Opposing to this, a study reported lower explosive power among male endurance athletes, with no significant difference in agility [ 40 ]. Decrease in performance, particularly in endurance activities, have been related to dietary intake restriction, and male athletes often reported to reduce food intake or under-eat during competitions [ 41 – 43 ].…”

Mapping the complexities of Relative Energy Deficiency in Sport (REDs): development of a physiological model by a subgroup of the International Olympic Committee (IOC) Consensus on REDs

“…Another study involved trained male endurance athletes who undertook a stepwise series of 14-day exposures equivalent to 25%, 50% and 75% reduction in their baseline estimated EA, with stages equivalent to overall EA of ~22, 17 and 9 kcal/kg FFM 43. Most other controlled field-based prospective investigations of EA exposure in athletes or active people have involved comparison of a single, severe16 44–49 (eg, 10–15 kcal/kg FFM/day) or moderate50–53 (20-25 kcal/kg FFM/day) restriction of EA compared with ‘adequate’/’high’ EA or energy balance (40–50 kcal/kg FFM/day), with interventions lasting from 3 to 9 days. Other prospective observational studies54–56 have identified self-imposed differences in EA in athletes over periods of 5 days to 12 weeks, enabling differences in health or performance outcomes between LEA exposures to be assessed.…”