Cardiovascular responses to prolonged eccentric cycling Ritter O. 1,2, Isacco L. 3, Tordi N. 1,4, Degano B. 5, Bouhaddi M. 5, Rakobowchuk M. 6 & Mourot L. 4,6 1 EA 4267 FDE, Plateforme EPSI, Université de Franche-Comté 2 Centre de Réadaptation Cardiologique et Pneumologique de Franche- Comté (CRCP-FC) 3 EA 4660 C3S, Plateforme EPSI, Université de Franche-Comté 4 Inserm CIC-CIT 808, CHRU de Besançon, France 5 EA 3920 “Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires”, UFR SMP, Université de Franche- Comté 6 Collège de la Santé et des Sciences de la Vie, Université de Brunel, Londres, Royaume-Uni EA 4267 FDE Fonctions et dysfonctions épithéliales

Introduc tion Methods Results Discussi on Conclusi on ECC contraction CONC contraction C ONCENTRIC AND E CCENTRIC EXERCISE  Lower cardio-respiratory sollicitations  Higher mechanical power ECC compared with CONC Matched for Power V’O 2 (Isner-Horobeti et al., 2013), (Melo et al., 2008), (Barnes, Trombold, Dhindsa, Lin, & Tanaka, 2010) + efficient + force development  Inflammation  Endothelial function impairment  Impaired ANS activity 2

Introduc tion Methods Results Discussi on Conclusi on O BJECTIVES  Litterature: only short CONC and ECC bouts 5 to 10 minutes (Dufour et al., 2007) / resistance training  Compare acute effects of prolonged aerobic (45min) CONC and ECC cycling: o Matched with a similar cardiac sollicitation : HR (easy + rehabilitation) o On cardiovascular system o On Autonomic Nervous System (ANS) balance o On endothelial function 3

MCE T ECC cycling CONC cycling n=10 n=5 CONC cycling ECC cycling randomiza tion 45’1 month45’ Introduc tion Methods Results Discussi on Conclusi on P ROTOCOL M EASURES HR, SAP and DAP, CO, SV, V’O 2, baroreflex Rest Warming Exercise 0’5’45’ Baselin e Target Matching HR 15’, 30’ and 45’ of exercise 45’ rec Recovery Endothe lial function 4

Introduc tion Methods Results Discussi on Conclusi on PARTICIPANTS (n = 10 males, 30±6 years, BMI 23±3 kg.m -2 ) V ̇ O 2 (L.min -1 )SAP (mmHg)DAP (mmHg)CO (L.min -1 ) CONECCCONECCCONECCCONECC Base 0.32 ± ± ± ± 1156 ± 652 ± 77.5 ± ± 0.9 Target 1.21 ± 0.16 * 0.92 ± ± ± 1174 ± 7 * 85 ± ± ± ' 1.30 ± ± ± ± 1471 ± 10 * 81 ± ± ± ' 1.33 ± ± ± ± 1867 ± 8 * 77 ± ± ± '1.32 ± ± ± ± 1465 ± 8 * 77 ± ± ± 2.6 Mean power performed → CONC: 82 ± 16 W ; 97 ± 9 bpm → ECC: 210 ± 40 W ; 100 ± 10 bpm G ENERAL RESPONSES TO EXERCISE * significant difference between CON and ECC repeated measures ANOVA 5

Introduc tion Methods Results Discussi on Conclusi on HR AND SV EVOLUTION DURING EXERCISE CONC ECC HRHR SVSV * significant difference from CON † significant difference from Target repeated measures ANOVA 6

Introduc tion Methods Results Discussi on Conclusi on ANS RESPONSES DURING EXERCISE : BAROREFLEX ( SEQUENCE METHOD ) N of sequences Slop e CONC ECC 7 * significant difference from CON † significant difference from Target repeated measures ANOVA

Introduc tion Methods Results Discussi on Conclusi on E NDOTHELIAL FUNCTION AFTER EXERCISE  Flow mediated dilation (FMD) of brachial artery o CONC: no differences from Baseline o ECC: attenuated flow mediated dilation (FMD) 45’ after exercise cessation → endothelial dysfunction 8

Introduc tion Methods Results Discussi on Conclusi on  During ECC (vs CONC matched with HR at exercise onset): o = V’O 2 and = CO, but ↑ DAP, ↓ SV and ↑ HR ≠ Dufour et al. (2007): higher CO, SV and HR during a 6-min ECC than CONC cycling (matched with V’O 2 ) o ↓ N of baroreflex sequences  After ECC o ↓ FMD F INDINGS 9

Introduc tion Methods Results Discussi on Conclusi on H YPOTHESES impeded rib cage expansion → intra-thoracic overpressure limit SV increase  Lechauve et al. (2014) ECC: greater muscle mass involvement (biceps brachii EMG)  Endothelial dysfunction Inflammation (higher muscle tension) Higher sympathetic activity 10  Muscle mechanoreflex (Dufour et al. 2007) o Lower baroreflex o Greater peripheral resistances Superior DAP and lower SV increase

Introduc tion Methods Results Discussi on Conclusi on  During ECC (after 10 min): o Impeded SV so higher HR to maintain CO o Increased peripheral resistances → greater DAP o Baroreflex impairment → ANS imbalance o Macrovascular endothelial dysfunction  Study long-term (chronic) effects of ECC cycling → rehabilitation C ONCLUSION AND PERSPECTIVES Increased constraints on cardiovascular system Acute adverse effects 11

Cardiovascular responses to prolonged eccentric cycling Ritter O. 1,2, Isacco L. 3, Tordi N. 1,4, Degano B. 5, Bouhaddi M. 5, Rakobowchuk M. 6 & Mourot L. 4,6 1 EA 4267 FDE, Plateforme EPSI, Université de Franche-Comté 2 Centre de Réadaptation Cardiologique et Pneumologique de Franche- Comté (CRCP-FC) 3 EA 4660 C3S, Plateforme EPSI, Université de Franche-Comté 4 Inserm CIC-CIT 808, CHRU de Besançon, France 5 EA 3920 “Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires”, UFR SMP, Université de Franche- Comté 6 Collège de la Santé et des Sciences de la Vie, Université de Brunel, Londres, Royaume-Uni

Introduc tion Methods Results Discussi on Conclusi on P ARTICIPANTS (n = 10 males) Mean ± SDRange Age (y)29.6± Weight (kg)73.3± Height (cm)177.9± BMI (kg.m -2 )23.2± Pmax (watt)305.6± V’O 2 max (mL. kg - 1.min -1 )49.6± RQmax1.16±