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- Stenqvist, Thomas Birkedal, et al.
(författare)
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Impact of a 4-Week Intensified Endurance Training Intervention on Markers of Relative Energy Deficiency in Sport (RED-S) and Performance Among Well-Trained Male Cyclists
- 2020
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Ingår i: Frontiers in Endocrinology. - : Frontiers Media S.A.. - 1664-2392. ; 11, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Cyclists often apply block periodization to high training volumes in meso- and macrocycles to optimize training adaptation and to prepare for competition. Body mass influences performance in many sports, including endurance disciplines, and conditions related to the syndrome Relative Energy Deficiency in Sports (RED-S) such as metabolic adaptations and premature osteoporosis have also been reported in male cyclists. This study aimed to determine how a 4-week mesocycle of intensified endurance training designed to increase performance, would affect markers of RED-S in well-trained male cyclists. Twenty-two participants (age: 33.5 +/- 6.6 years, height: 181.4 +/- 5.2 cm, weight: 76.5 +/- 7.4 kg, peak oxygen uptake (VO2peak): 63.5 +/- 6.6 mL center dot kg(-1)center dot min(-1)) were recruited and instructed to maintain their background training load and to follow a supervised training protocol consisting of three high-intensity interval training sessions per week with a work duration of 32 min per session. Protocols included pre- and postintervention assessment of resting metabolic rate (RMR) using a ventilated hood, body composition and bone health by dual-energy X-ray absorptiometry (DXA), blood samples, energy intake, and aerobic performance. The interval training increased participants' aerobic performance-peak power output [4.8%,p< 0.001], VO2peak[2.4%,p= 0.005], and functional threshold power [6.5%,p< 0.001] as well as total testosterone levels [8.1%,p= 0.011]-while no changes were observed in free testosterone [4.1%,p= 0.326]. Bodyweight, body composition, and energy intake were unchanged from pre- to post-test. Triiodothyronine (T-3) [4.8%,p= 0.008], absolute RMR [3.0%,p= 0.010], relative RMR [2.6%,p= 0.013], and RMRratio[3.3%,p= 0.011] decreased, and cortisol levels increased [12.9%,p= 0.021], while no change were observed in the total testosterone:cortisol ratio [1.6%,p= 0.789] or the free testosterone:cortisol (fT:cor) ratio [3.2%,p= 0.556]. A subgroup analysis of the five participants with the largest increase in fT:cor ratio, revealed a greater improvement in functional threshold power (9.5 vs. 2.5%,p= 0.037), and higher relative RMR (0.6 vs. -4.2%p= 0.039, respectively). In conclusion, 4 weeks of intensified endurance interval training increased the athletes' aerobic performance and testosterone levels. However, negative changes in markers related to RED-S, such as a reduction in RMR and T-3, and an increase in cortisol were observed. These results indicate the complexity involved, and that male athletes are at risk of developing clinical indications of RED-S even during a short 4-week endurance training mesocycle.
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| 2. |
- Stenqvist, Thomas Birkedal, et al.
(författare)
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Prevalence of Surrogate Markers of Relative Energy Deficiency in Male Norwegian Olympic-Level Athletes
- 2021
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 31:6, s. 497-506
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Tidskriftsartikel (refereegranskat)abstract
- The syndrome of Relative Energy Deficiency in Sport (RED-S) includes wide-ranging effects on physiological and psychological functioning, performance, and general health. However, RED-S is understudied among male athletes at the highest performance levels. This cross-sectional study aimed to investigate surrogate RED-S markers prevalence in Norwegian male Olympic-level athletes. Athletes (n = 44) aged 24.7 +/- 3.8 years, body mass 81.3 +/- 15.9 kg, body fat 13.7% +/- 5.8%, and training volume 76.1 +/- 22.9 hr/month were included. Assessed parameters included resting metabolic rate (RMR), body composition, and bone mineral density by dual-energy X-ray absorptiometry and venous blood variables (testosterone, free triiodothyronine, cortisol, and lipids). Seven athletes (16%) grouped by the presence of low RMR (RMRratio < 0.90) (0.81 +/- 0.07 vs. 1.04 +/- 0.09, p <.001, effect size 2.6), also showed lower testosterone (12.9 +/- 5.3 vs. 19.0 +/- 5.3 nmol/L, p =.020) than in normal RMR group. In low RMRratio individuals, prevalence of other RED-S markers (-subclinical-low testosterone, low free triiodothyronine, high cortisol, and elevated low-density lipoprotein) was (N/number of markers): 2/0, 2/1, 2/2, 1/3. Low bone mineral density (z-score < -1) was found in 16% of the athletes, all with normal RMR. Subclinical low testosterone and free triiodothyronine levels were found in nine (25%) and two (5%) athletes, respectively. Subclinical high cortisol was found in 23% of athletes while 34% had elevated low-density lipoprotein cholesterol levels. Seven of 12 athletes with two or more RED-S markers had normal RMR. In conclusion, this study found that multiple RED-S markers also exist in male Olympic-level athletes. This highlights the importance of regular screening of male elite athletes, to ensure early detection and treatment of RED-S.
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| 3. |
- Stenqvist, Thomas Birkedal, et al.
(författare)
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Relative Energy Deficiency in Sport (REDs) Indicators in Male Adolescent Endurance Athletes : A 3-Year Longitudinal Study
- 2023
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 15:24
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Tidskriftsartikel (refereegranskat)abstract
- Longitudinal measurements of Relative Energy Deficiency in Sport (REDs) among adolescent male elite athletes are lacking. We aimed to monitor REDs indicators and their possible impact on performance in elite high-school cross-country skiing and biathlon athletes (n = 13) (16.3 +/- 0.4 years, 179.4 +/- 7.6 cm, 63.6 +/- 8.2 kg body mass (BM), and peak oxygen uptake (VO2peak): 61.5 +/- 5.3 mL/kg BM/min) every 6 months for 3 years. Protocols included assessments of energy availability (EA), body composition and bone mineral density (BMD), resting metabolic rate (RMR), disordered eating behavior, exercise addiction, VO2peak, and muscle strength. Data were analyzed using a linear mixed model. At baseline, 38% had low lumbar BMD (Z-score <= -1), and overall, bone health increased only slightly. VO2peak and muscle strength improved (p < 0.001), RMR decreased (p = 0.016), and no change was observed in EA or physiological or psychological REDs indicators. Conclusively, many of these young male athletes had poor bone health at baseline, and most either lost or did not achieve the expected pubertal bone mineral accrual, although no other indication of REDs was observed, while performance improved during the study period. Our findings highlight the importance of elite sports high schools focusing on screening for early detection of impaired bone health in male athletes.
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| 4. |
- Torstveit, Monica K, et al.
(författare)
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Exercise dependence, eating disorder symptoms and biomarkers of Relative Energy Deficiency in Sports (RED-S) among male endurance athletes
- 2019
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Ingår i: BMJ Open Sport & Exercise Medicine. - : BMJ Publishing Group Ltd. - 2055-7647. ; 5:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To explore associations betweenexercise dependence, eating disorder (ED) symptoms and biomarkers of Relative Energy Deficiency in Sports (RED-S) among male endurance athletes.Methods Fifty-three healthy well-trained male cyclists, triathletes and long-distance runners recruited from regional competitive sports clubs were included in this cross-sectional study. The protocol comprised the Exercise Dependence Scale (EXDS), the ED Examination Questionnaire (EDE-Q), measurements of body composition, resting metabolic rate, energy intake and expenditure and blood analysis of hormones and glucose.Results Participants with higher EXDS score displayed a more negative energy balance compared with subjects with lower EXDS score (p<0.01). EXDS total score was positively correlated with EDE-Q global score (r=0.41, p<0.05) and the subscale score for restraint eating (r=0.34, p<0.05) and weight concern (r=0.35, p<0.05). EXDS total score and the subscales lack of control and tolerance were positively correlated with cortisol (r=0.38, p<0.01, r=0.39, p<0.01 and r=0.29, p<0.05, respectively). The EXDS subscales withdrawal and tolerance were negatively correlated with fasting blood glucose (r=−0.31 and r=−0.32, p<0.05, respectively), while intention effect was negatively correlated with testosterone:cortisol ratio (r=−0.29, p<0.05) and positively correlated with cortisol:insulin ratio (r=0.33, p<0.05).Conclusion In this sample of healthy male athletes, we found associations between higher EXDS scores, ED symptoms and biomarkers of RED-S, such as a more pronounced negative energy balance and higher cortisol levels.
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