The effects of intensified training on resting metabolic rate (RMR), body composition and performance in trained cyclists

Abstract

BackgroundRecent research has demonstrated decreases in resting metabolic rate (RMR), body composition and performance following a period of intensified training in elite athletes, however the underlying mechanisms of change remain unclear. Therefore, the aim of the present study was to investigate how an intensified training period, designed to elicit overreaching, affects RMR, body composition, and performance in trained endurance athletes, and to elucidate underlying mechanisms.MethodThirteen (n = 13) trained male cyclists completed a six-week training program consisting of a “Baseline” week (100% of regular training load), a “Build” week (~120% of Baseline load), two “Loading” weeks (~140, 150% of Baseline load, respectively) and two “Recovery” weeks (~80% of Baseline load). Training comprised of a combination of laboratory based interval sessions and on-road cycling. RMR, body composition, energy intake, appetite, heart rate variability (HRV), cycling performance, biochemical markers and mood responses were assessed at multiple time points throughout the six-week period. Data were analysed using a linear mixed modeling approach.ResultsThe intensified training period elicited significant decreases in RMR (F(5,123.36) = 12.0947, p = <0.001), body mass (F(2,19.242) = 4.3362, p = 0.03), fat mass (F(2,20.35) = 56.2494, p = <0.001) and HRV (F(2,22.608) = 6.5212, p = 0.005); all of which improved following a period of recovery. A state of overreaching was induced, as identified by a reduction in anaerobic performance (F(5,121.87) = 8.2622, p = <0.001), aerobic performance (F(5,118.26) = 2.766, p = 0.02) and increase in total mood disturbance (F(5, 110.61) = 8.1159, p = <0.001).ConclusionIntensified training periods elicit greater energy demands in trained cyclists, which, if not sufficiently compensated with increased dietary intake, appears to provoke a cascade of metabolic, hormonal and neural responses in an attempt to restore homeostasis and conserve energy. The proactive monitoring of energy intake, power output, mood state, body mass and HRV during intensified training periods may alleviate fatigue and attenuate the observed decrease in RMR, providing more optimal conditions for a positive training adaptation.

Ketone ester supplementation blunts overreaching symptoms during endurance training overload

“…Sprint performance decreased in all subjects (range: −1 to −12%), whilst endurance performance in TT 30min on average was stable (range: −4 to +12%), which corroborates earlier findings (Woods et al . ). Sprint performance restored to baseline within 3 days of recovery, while performance improvements in TT 30min only occurred by day +7.…”

“…Thus, lower basal metabolic rate effected by a decrease in leptin (Woods et al. , ) might explain the absence of body weight drop in CON despite energy expenditure in training exceeding energy intake during the later stage of the training period.…”

“…Appetite was assessed immediately before breakfast using a validated 0–10 Likert visual analog scale (VAS), adapted from Woods et al . (). Subjects were provided with four appetite or satiety questions (‘How hungry do you feel?’, ‘How full do you feel?’, ‘How satisfied do you feel?’, ‘How much do you think you could eat now?’).…”

“…(ii) gastrointestinal discomfort; and (iii) recovery-stress state. Appetite was assessed immediately before breakfast using a validated 0-10 Likert visual analog scale (VAS), adapted from Woods et al (2018). Subjects were provided with four appetite or satiety questions ('How hungry do you feel?'…”

Physical condition of female students with different level of body mass deficiency

“…It is determined the decrease in the motivation of students to physical culture training [19]. A lot of researchers consider the following reasons of students' body mass deviation from the norm: hypodynamia [20,21], a disorder of nutritional status [22], hormonal changes in the organism [23], the influence of psychogenic factors [24]. The increase of intellectual and psychoemotional loads, noncompliance with a base of a healthy lifestyle by students [2,30], interest in computer games and Internet influence negatively on physical [25,26], mental [27] and somatic [28,29] health of the youth.…”