Abstract A waist-to-height ratio (WHtR) above 0.5 is considered a threshold for elevated cardiometabolic risk. However, whether this cutoff is associated with altered cardiac autonomic control at rest, during exercise, and throughout post-exercise recovery remains unclear. This study compared cardiac autonomic indexes between young men categorized according to WHtR. Thirteen young men (24.8 ± 4.4 years) with WHtR ≥ 0.5 (G1) and 18 age-matched men (23.1 ± 4.1 years) with WHtR < 0.5 (G2) performed a maximal graded exercise test on a treadmill. Heart rate and heart rate variability measurements were taken at rest, during exercise, and throughout recovery using a portable cardiac monitor. At rest, G1 exhibited higher resting heart rate (81 ± 13 vs. 71 ± 8 bpm; P = 0.014) and lower parasympathetic activity (P < 0.05) compared with G2. During exercise, the percentage of chronotropic response did not differ between groups (G1: 92 ± 7% vs. G2: 95 ± 7%; P = 0.233). On post-exercise recovery, G1 had decreased heart rate recovery after 300 s (G1: 60 ± 8 bpm vs. G2: 69 ± 8 bpm; P = 0.007) and decreased cardiac parasympathetic reactivation (P < 0.05) compared with G2. Overall, young men with high and low WHtR exhibit similar chronotropic responses to maximal exercise, but individuals with high WHtR have impaired baseline cardiac autonomic control and slower post-exercise cardiac autonomic recovery.

Abstract The global epidemic of diabetes mellitus (DM) presents a significant health challenge, and physical exercise is crucial in managing type 2 DM (T2DM). Sodium bicarbonate (SB) supplementation may enhance high-intensity exercise performance. This study aimed to analyze acute physical performance, blood glucose, and cardiovascular responses following SB or placebo supplementation in middle-aged and elderly adults with T2DM. Thirteen T2DM participants (62.15 ± 6.90 years; body mass index 29.14 ± 4.49 kg/m2) performed a maximal incremental treadmill test after ingesting SB (0.3 g/kg) or placebo in a triple-blind, randomized crossover design. Blood pressure (BP), heart rate (HR), and capillary blood glucose were measured preand post-test. SB significantly increased exercise performance (481 ± 116.97 s vs. 439 ± 99.92 s with placebo; p = 0.005) and was associated with a greater reduction in post-exercise blood glucose (p = 0.0001), which was attributed to the longer exercise duration. However, it did not potentiate the acute reduction in blood glucose typically induced by exercise. No significant differences were found between SB and placebo conditions for BP, HR, or other cardiovascular measures (p > 0.05). Acute SB supplementation improved exercise tolerance and reduced blood glucose in individuals with T2DM, indicating a potential ergogenic strategy to improve exercise performance. However, it had no observable acute impact on cardiovascular variables. These preliminary findings suggest that SB may be a safe, short-term aid to enhance high-intensity exercise performance in T2DM, but confirmation in larger studies is needed.

Transcranial direct current stimulation (tDCS) is a potential ergogenic method for enhancing endurance exercise performance. However, its effects across different running distances under field conditions remain unclear. This study evaluated the effects of tDCS on 5000 m and 10,000 m running performance. In all, 16 trained recreational runners participated in four experimental trials in a counterbalanced crossover design: anodal tDCS and sham conditions. Stimulation was applied over the bilateral motor cortices for 20 min at 2 mA. Immediately after stimulation, participants completed a running time trial. Overall completion time and kilometer splits were recorded. Heart rate (HR) and rating of perceived exertion (RPE) were measured. The repeated-measures analysis of variance (ANOVA) revealed no significant condition × distance interaction (p = 0.852) and no significant main effect of condition (p = 0.069), indicating that anodal tDCS did not significantly affect endurance running performance or that its effects differed between the 5000 m and 10,000 m trials. During the 5000 m trial, condition effects were observed for running speed and heart rate (p < 0.05), whereas no significant condition effects were observed during the 10,000 m trial. Rating of perceived exertion did not differ between conditions (p > 0.05). The present study did not demonstrate a significant effect of anodal tDCS on 5000 m and 10,000 m running performance. Future studies should further investigate the effects of anodal tDCS across different endurance exercise protocols and populations.

This study aimed to investigate whether heart rate recovery (HRR) is a predictor of all-cause mortality in a 72-month survival analysis. In this cohort study, 578 individuals who underwent a maximal exercise test at a university hospital between August 2012 and August 2018 were followed for up to 72 months. Participants performed a maximal incremental treadmill test, followed by an active recovery period phase to evaluate their HRR. When the decay of heart rate totaled ≥ 13bpm in the first minute post-exercise a normal HRR was considered, whereas an abnormal HRR was defined as ≤ 12bpm. Of the 578 individuals, 371 (64.2%) had normal HRR, whereas 207 (35.8%) had an abnormal HRR. The survival analysis showed significantly higher 72-month survival in the normal HRR group (93.8%) than in the abnormal HRR group (81.6%), with a 3.16 hazard ratio (95%CI: 1.86-5.35). Individuals with abnormal HRR were generally older, had a greater burden of comorbidities, shorter time to exhaustion, lower peak heart rate, and higher heart rate 60 seconds after the exercise. Thus, HRR predicted 72-month all-cause mortality. These findings suggest the use of HRR as a simple, non-invasive prognostic tool in clinical practice, particularly for stratifying mortality risk.

Purpose: To compare the development of fatigability during a moderate-intensity cycling exercise between women with fibromyalgia (FM) and control women (CON) after acute ingestion of caffeine and placebo. Methods: Ten FM and 10 CON women performed a 30-min moderate-intensity cycling exercise 1 h after the ingestion of a capsule containing either caffeine or a placebo. Fatigability and its central and peripheral determinants were determined via changes from pre- to post-15 and post-30 min of exercise in maximal voluntary isometric contractions, voluntary activation (VA), and quadriceps potentiated twitch torque (Q(tw-pot)), respectively. Heart rate, muscle oxygen saturation, perceptive responses, mood state, localized and widespread pain, and sleepiness were also monitored during and after exercise. Results: There was a time versus group interaction for maximal voluntary isometric contraction and VA (P < 0.001) but not for Q(tw-pot) (P = 0.363), indicating a greater rate of fatigability development, mainly caused by central mechanisms, in the FM than in the CON group. There was also a main effect of condition for VA (P = 0.011), indicating that caffeine attenuates central mechanisms of fatigability in both groups. Caffeine ingestion also increased muscle oxygenation, perceived vigor, and energy, and decreased leg muscle pain, sleepiness, and perceived fatigue in both groups. However, caffeine improved perceived pleasure/displeasure and exercise adherence likelihood only in the FM group. Conclusions: Compared with CON, women with FM present a greater rate of fatigability during exercise, mainly of central origin. Caffeine seems to be a promising bioactive to counteract the central mechanisms of fatigability and improve the exercise experience among FM women.

Fibromyalgia (FM) patients present impaired cardiac autonomic regula-tion during maximal exercise; however, it is unknown whether these al-terations also manifest during submaximal exercise. The aim of this study was to compare the on-transient heart rate (HR) response and HR variability during a constant-load submaximal cycling exercise between FM and control (CON) women. Ten women with FM (age: 45.2±9.3 years) and 10 age-matched CON women (age: 48.4±6.1 years) performed a 15-min cycling exercise, with the work rate fixed at 50% of the individual peak power output attained in a maximal graded exercise test. The time intervals between consecutive heartbeats were recorded regularly during the exercise for subsequent analysis of on-transient HR response and HR variability indices. The on-transient HR time constant was simi-lar (p=0.83) between the FM (41.0±14.1 sec) and CON (42.2±10.4 sec). During the 5–10 and 10–15 min of exercise, HR variability indices indi-cating sympathetic and parasympathetic activities were similar (p>0.05) between FM and CON groups. In conclusion, women with FM present-ed a normal cardiac autonomic response to submaximal cycling exer-cise. These findings have clinical relevance, as submaximal exercises are commonly prescribed for FM patients.

Purpose The aim of this study was to verify the association between pre-stroke physical fitness and acute ischemic stroke (AIS) outcomes. Methods Forty patients were evaluated within a window of 72 h was used for assessments. Stroke outcomes were analyzed by two scales: the modified Rankin Scale for the global outcome, and the Motor Assessment Score for the motor outcome. Thereafter, patients performed two physical fitness tests to evaluate pre-stroke function: the handgrip strength test and the 30-s arm curl test. Results Arm curl performance and handgrip strength were associated with stroke global outcome (arm curl performance R 2 = 0.353; p < 0.001; handgrip strength R 2 = 0.275; p = 0.001) and motor outcome (arm curl performance R 2 = 0.223; p = 0.002; handgrip strength R 2 = 0.199; p = 0.004). Conclusion Pre-stroke physical fitness is related to better global and motor stroke outcomes. Future studies could confirm if these associations between pre-stroke physical fitness and stroke outcomes can predict the long-term sequelae after an event.

Objectives. - Whether performance fatigability and its determinants (i.e., peripheral and central fatigue) after cycling exercise performed at extreme- and severe-intensity domains are of similar magnitude is unknown. In the current study, we investigated the levels of performance fatigability and peripheral and central fatigue in nine young female after a cycling exercise performed until the limit of tolerance at extreme- (i.e., 140% of peak power output) and severe-intensity domains (80% of the difference between gas exchange threshold and peak power output). Equipment and methods. - The level of maximal voluntary isometric contraction (MVC), potentiated quadriceps twitch force evoked by single pulse (Qtw), and voluntary activation (VA) were measured pre- and post-exercise.Results. - The MVC (a marker of performance fatigability) decreased from pre- to post-exercise( P < 0.05) in the extreme- (-10 +/- 8%) and severe-intensity (-10 +/- 10%) exercises. The Qtw(amarker of peripheral fatigue) reduced similarly from pre- to post-exercise (P < 0.05) in theextreme(-18 +/- 15%) and severe-intensity (-10 +/- 17%) exercises. The VA (a marker of centralfatigue) did not reduce from pre- to post-exercise in either severe- (2 +/- 7%) or extreme-intensity(2 +/- 7%) exercises (P > 0.05). Conclusions. - These findings suggest a similar amount of performance fatigability and peripheral fatigue after severe- and extreme-intensity cycling exercises in young female, which is inaccordance with the concept that exercises performed above critical power until task failureattain a common level of peripheral fatigue regardless of exercise intensity. (c) 2023 Elsevier Masson SAS. All rights reserved.

The aim of this study was to verify the influence of caffeine (CAF) on time to exhaustion in a maximal incremental exercise test and cardiac autonomic indexes recovery in chronic obstructive pulmonary disease (COPD) patients. In a randomized, double-blinded, placebo-controlled and crossover experimental design, eleven patients diagnosed with COPD performed an incremental test after ingesting CAF (5 mg kg−1) or placebo (PLA) (cellulose). CAF or PLA was administered 60 min before the test. Peripheral oxygen saturation was analyzed throughout the tests. Heart rate recovery (HRR) and variability (HRV) were analyzed after exhaustion in both tests. Additionally, six patients completed a spirometry after ingesting a capsule of caffeine. The time to exhaustion in the incremental test with CAF (355.8 ± 171.1 s) was 2.1% longer than in the PLA test (348.5 ± 209.1 s), but there was no statistical difference (p = 0.70). Similarly, no statistical differences were observed in HRR and HRV between PLA and CAF (p > 0.05 for all analyses). The peripheral oxygen saturation values were lower at exhaustion but without a statistical difference (CAF = 92.3 ± 4.4% vs. PLA = 91.5 ± 2.7%; p > 0.05). After spirometry, the effect of CAF on FEV1 (Before CAF = 1.43 ± 0.75 L vs. After CAF = 1.47 ± 0.70 L; p = 0.17) was not demonstrated. Caffeine does not change incremental test performance and autonomic recovery response in patients with COPD. These results suggest caffeine would not have an ergogenic effect in patients with COPD.

The purpose of this study was to verify the influence of physical activity level on the length of hospital stay in older men recovered from COVID-19. In total, 126 older men diagnosed with COVID-19 were admitted to the hospital between September and December 2020. Among them, 70 survived, of which 39 older men were included in the study. Within 30 days after discharge, patients answered the International Physical Activity Questionnaire to measure their physical activity level through phone contact, with questions corresponding to the week before symptom onset. Clinical and laboratorial data from admission, days between onset of symptoms and admission, length of stay, computed tomography abnormalities, and the need for the intensive care unit were collected. The groups (active × sedentary) were compared using the Student t test or Mann–Whitney test for quantitative data and chi-square test was used for categorical data. There is no difference between the groups in characteristics of admission ( p > 0.05), except by potassium level. Active older men had a shorter length of stay (6.50 ± 3.46 vs 11.48 ± 7.63 days; p = 0.03), disease duration (15.71 ± 4.84 vs 21.09 ± 7.69 days; p = 0.02), and lower frequency of lung damage when compared to their sedentary counterparts. In conclusion, being physically active prior to infection can attenuate length of hospital stay in older men with COVID-19.

OBJECTIVE:Exacerbated perceived exertion and muscle pain responses during exercise might limit physical activity practice in fibromyalgia patients. Thus, nutritional strategies that can reduce perceived exertion and muscle pain during exercise in fibromyalgia patients would be useful. The purpose of this study was to investigate the effects of acute caffeine intake on the perceptions of exertion and muscle pain during a moderate intensity exercise in women with fibromyalgia.METHOD:Using a randomized, double-blinded, placebo-controlled and crossover experimental design, eleven sedentary women diagnosed with fibromyalgia (age: 44.6 ± 10.5 years; body mass index: 28.5 ± 4.5 kg.m-2) ingested a capsule containing either caffeine (5 mg per kg of body mass) or cellulose (placebo), 60 minutes before performing a 30-minute constant-load cycling exercise, with work rate fixed at 50% of their individual peak workload attained in an incremental exercise test. Ratings of perceived leg muscle pain and perceived exertion were assessed every 5 minutes of exercise.RESULTS:The perceived leg muscle pain was similar (F(1,10) = 1.18, p = 0.30, ŋ2 = 0.11) between caffeine (2.1 ± 1.2 arbitrary units) and placebo conditions (2.2 ± 0.9 arbitrary units). The perceived exertion, however, was on average 8 ± 6% lower (F(1,10) = 12.13; p = 0.006; ŋ2 = 0.55) during exercise in the caffeine condition (12.4 ± 1.3 arbitrary units) than in the placebo condition (13.1 ± 1.1 arbitrary units).CONCLUSIONS:These findings indicate that acute caffeine intake could be an attractive strategy to attenuate the exacerbated perceived exertion of fibromyalgia patients during moderate intensity exercise.

Abstract The purpose of this study was to investigate the effects of supervised moderate combined exercise training in patients with post-COVID in the physical and functional capacity. Forty-one patients completed 6-week combined moderate exercise training. In baseline and after intervention, patients were assessments of screening, including clinical data and anthropometrics performed functional tests, which consisted of handgrip strength test, chair sit and reach test, arm curl test, 30-sec sit to stand test, timed up and go, and six-minute walk test (6MWT). Primary outcomes were results of functional tests, and secondary outcomes were clinical data. Handgrip strength (p < 0.001), flexibility (p = 0.01), strength of upper (p = 0.01) and lower limbs (p < 0.001), gait speed (p < 0.001) and 6MWT (p < 0.001) improved after rehabilitation. Resting heart rate, systolic and diastolic blood pressure were lower after intervention (p = 0.01; p = 0.05; p = 0.03, respectively). No one difference was observed in persistent symptoms (p > 0.05). In conclusion, exercise training promoted great physical, functional and cardiovascular benefits for post-COVID patients.

Abstract Giovanini, B, Altimari, LR, de Paula Ramos, S, Alves Okazaki, VH, Okuno, NM, and Junior, AF. Preconditioning effects of photobiomodulation on repeated-sprint ability of professional basketball players. J Strength Cond Res 37(1): 224–229, 2023—The purpose of this study was to investigate the preconditioning effects of photobiomodulation on repeated-sprint ability of professional basketball players. Ten professional basketball players took part in this randomized, double-blind, placebo-controlled, crossover study. The subjects attended 2 repeated-sprint test sessions. In each session, the subjects performed a general warm-up, followed by a familiarization sprint. Afterward, the subjects received either the photobiomodulation (660 and 850 nm, 12 J·cm−2, 83.4 J per point, 10 points, light-emitting diode [LED] treatment) or placebo intervention and performed the repeated-sprint test. The repeated-sprint test consisted of ten 30-m sprints with 1 change of direction (15 + 15 m), interspersed by 30 seconds of passive recovery. Sprint times and heart rate responses were monitored during the test. To compare moments and conditions, linear mixed-effects models were applied with statistical significance set at p < 0.05, and Cohen's d was used as effect size (ES). The LED treatment could not improve total time (p = 0.662; ES = −0.06), best time (p = 0.869; ES = 0.02), fatigue index (p = 0.169; ES = 0.64), or sprint decrement (p = 0.124; ES = −0.75) when compared with the placebo condition. In addition, mean heart rate (p = 0.687; ES = 0.07) and maximal heart rate (p = 0.837; ES = −0.03) were similar between conditions. We concluded that the LED condition could not improve the repeated-sprint ability of professional basketball players.

Objectives. - To investigate the effects of prior high-intensity endurance exercise on time trial (TT) performance and fatigue responses. Equipment and methods. - Eleven male cyclists visited the lab in two separate visits. The first visit was composed by a maximal cycling incremental test (MIT) followed by 15 min of passive rest before a 4-km cycling TT. The second visit (control, CON) was composed by moderate-intensity exercise for 5 min before the TT. Fatigue of knee extensors was assessed by isometric maximal voluntary contractions (IMVC), while the central (voluntary activation [VA]) and peripheral fatigue (peak torque of potentiated twitches [TwPt]) were evaluated using electrically-evoked contractions performed before and 1 min after the TT. Power output (PO), oxygen uptake ((V) over dotO(2)) and rating of perceived exertion (RPE) were recorded throughout the TT. Results. - TT performance (+2.6%) and average PO (+5.7%) improved in MIT compared to CON condition. While peripheral fatigue level was greater in MIT condition (P < 0.05), the central fatigue was lower compared to CON condition (P < 0.05). There were greater overall (V) over dotO(2) values (3.9 +/- 0.4 vs 3.6 +/- 0.4 L.min(-1)) but similar RPE responses (15 +/- 2 vs 15 +/- 3 a.u.) in MIT compared to CON. These findings indicate that prior high-intensity endurance exercise has positive effects in subsequent TT performance compare to moderate-intensity warm-up, despite exacerbated peripheral fatigue development. This response might be driven by greater aerobic reliance and exertion tolerance. (C) 2021 Elsevier Masson SAS. All rights reserved.

The aim of this study was to compare the physical fitness and cardiac autonomic activity among women with moderate and severe fibromyalgia (FM) and healthy women. This study included 35 women with FM (age: 46.2±8.9 years) and 17 healthy women (age: 44.3±9.9 years). Participants with FM were divided into moderate FM (n=15) and severe FM (n=20) according to the total score obtained in FM impact questionnaire. The heart rate variability was monitored using a portable cardiac monitor with participants resting in supine position during 10 min. Thereafter, the participants performed the chair sit and reach test, the chair stand test, and the 6-min walk test to measure the lower-body flexibility, lower-body muscle strength, and cardiorespiratory fitness, respectively. The lower-body muscle strength and cardiorespiratory fitness were both reduced in moderate and severe FM compared to healthy women (P<0.01), with greater reduction in severe FM when compared to moderate FM (P<0.05). In addition, the parasympathetic indexes of heart rate variability were all similarly decreased in both moderate and severe FM, when compared to healthy women (P<0.05). The cardiac parasympathetic activity is similarly decreased in women with both moderate and severe FM in comparison to healthy women, despite a greater physical deconditioning in severe FM.

Objetivo: Investigar a influência da música de preferência no desempenho de resistência de força em exercícios dinâmicos com pesos em homens adultos jovens. Metodologia: Estudo transversal realizado com dez indivíduos do sexo masculino (idade 21,5 ± 3,3 anos, massa corporal 85,02 ± 17,18 kg, estatura 180,5 ± 6,59 cm), os quais realizaram testes de uma repetição máxima (1-RM) para os exercícios rosca direta e supino reto, a fim de determinar a carga do teste de resistência de força. Posteriormente, realizaram-se testes de resistência de força (quatro séries até a falha) a 70% de 1 RM, com e sem música de preferência. As variáveis analisadas nas quatro sessões foram o número de repetições, a percepção subjetiva de esforço (PSE), o estado de humor (∆BRUMS) e o índice de fadiga (IF). Resultados: Não existiu diferença ao se utilizar a música de preferência nos dois exercícios avaliados no número de repetições, IF e PSE (p>0,05). ∆BRUMS não foi influenciado em todas as dimensões do questionário na rosca direta (p>0,05) e em supino reto. Somente o vigor apresentou influência significante (p

espanolLa relacion entre la recuperacion de la frecuencia cardiaca (RFC) y las enfermedades cardiovasculares esta bien establecida, siendo que la RFC mas lenta se asocia con un mayor riesgo de muerte subita y muerte en general, y se ha demostrado que es un factor predictivo independiente tanto para las personas sanas como para las personas con enfermedades cardiacas. Sin embargo, no esta claro que indices de la fase rapida y lenta de la RFC tienen mayor confiabilidad despues del ejercicio maximo. Este estudio tuvo como objetivo verificar cual de los indices de RFC (T30, ΔFC60s, ΔFC300s y cinetica de FC) tienen mayor confiabilidad en adultos despues de las pruebas maximas de ejercicio. EnglishThe relationship between heart rate (HR) recovery (HRR) and cardiovascular diseases (CAD) is well stablished, being that slower HRR is associated with an increased risk of sudden death and overall death, and it has been demonstrated to be independent predictor for both healthy and cardiac diseases individuals. However, it is not clear about which indexes from fast and slow phase of HRR have greater reliability after maximal exercise. This study aimed to verified which of the HRR indexes (T30 and ΔHR60s for fast phase of recovery; ΔHR300s and HR off-kinetics for slow phase) have better reliability in adults after maximal exercise test.

O objetivo do presente estudo foi verificar o efeito de 12 semanas de um programa de hidroginástica sobre pressão arterial, a regulação autonômica cardíaca e sobre a composição corporal em mulheres obesas. A amostra foi composta por 11 mulheres adultas obesas (50,55 ± 5,09 anos; 82,31 ± 7,91 kg; 156,36 ± 6,86 cm). Foram realizadas mensurações de variáveis antropométricas, da composição corporal, pressão arterial sistólica e diastólica e da variabilidade da frequência cardíaca pré- e pós-intervenção. O programa de hidroginástica consistiu em 12 semanas de hidroginástica (2 vezes/semana). Foram encontradas diferenças significantes para a circunferência de cintura (p = 0,049), razão cintura-quadril (p = 0,009), percentual de gordura (p = 0,025) e percentual de massa magra (p = 0,025). Também, foi observada diferença significante para pressão arterial sistólica após a intervenção (p = 0,029). Além disso, não foram encontradas diferenças significantes para os índices da VFC (RRi, SDNN e RMSSD) após a intervenção (p = 0,259; p = 0,158; p = 0,091; respectivamente). Conclui-se que após as 12 semanas de hidroginástica foram encontradas melhoras na pressão arterial sistólica, em variáveis antropométricas e na composição corporal, mas não existiram alterações na variabilidade da frequência cardíaca em mulheres obesas.

This study investigated the residual effects of mental fatigue induced by the 30-minute incongruent Stroop Color Word task on subjectively perceived fatigue, reaction time, and heart rate variability (HRV) in 20 adult volunteers (10 men; 10 women). Dependent variables were assessed before, immediately after, and at 15, 30, 45, and 60 minutes after two conditions: (a) a 30-minute incongruent Stroop Color Word task (mental fatigue condition); or (b) a 30-minute control condition. At pre-testing, there were no significant differences between experimental conditions for any variable. However, there was a residual effect of mental fatigue on psychological responses for up to similar to 15 minutes after the experimental manipulation (p < 0.01). For the reaction time task, significant differences were observed only immediately after the mental fatigue, compared to the control condition (p < 0.0001). There were no significant differences between experimental conditions for any parameters of HRV at any testing period. In addition, there were no significant gender related differences at any period or in either condition for any variable. The data suggest that mental fatigue can alter psychological responses for up to similar to 15 min after its induction, and mental fatigue may impair cognitive reaction time performance without changing autonomic cardiac responses.

Background/Objective Evidence has suggested abnormal cardiac autonomic responses to exercise in patients with fibromyalgia (FM). However, it is not clear whether the dysautonomia represents a reduced physical fitness rather directly related to FM pathogenesis. Thus, we aimed to verify the cardiac autonomic responses before, during, and after a maximal incremental exercise in women with FM and whether these hypothesized alterations would be dependent with their physical fitness. Methods This is a cross-sectional study with 23 FM women and 17 healthy women. The participants performed a maximal incremental cycling test to determine their maximal workload (Wmax) and were further matched by their Wmax (14 FM patients, Wmax: 128.6 ± 16.2 W; and 14 healthy women, Wmax: 131.9 ± 15.9 W). Beat-to-beat heart rate (HR) was continuously monitored to calculate HR variability indexes at rest, chronotropic reserve during exercise, and HR recovery. Results Heart rate variability indexes related to vagal modulation were significantly lower in FM patients than in healthy women (p < 0.05). The chronotropic reserve and the HR recovery at 30, 120, 180, 300, and 600 seconds after exercise were all lower in FM patients compared with those of healthy women (p < 0.05). Similar findings were found when analysis was performed using the matched physical fitness subgroup. Conclusions The documented cardiac autonomic abnormalities at rest, during, and after exercise in FM patients persist even when physical fitness status is taken in account. Thus, strategies to attenuate the dysautonomia in FM patients must be considered.