Influence of body composition and physical fitness on arterial stiffness after marathon running.

BACKGROUND AND AIMS: Participation in exhaustive endurance sports competitions continues to be popular. Questions about the cardiovascular side effects of prolonged excessive exercise persist. Our study aimed to elucidate the acute effects of marathon running on arterial stiffness (AST) and to detect the role of body composition, fitness status, and inflammation. METHODS: Body composition was investigated in lean and obese recreational runners taking part in a marathon race. Fitness levels were determined in advance by a symptom-limited treadmill test to obtain the individual anaerobic threshold. Carotid to femoral pulse wave velocity (PWV), systolic and diastolic blood pressures (BP), and inflammatory markers (TNF-ɑ, IL-6, hsCRP) were measured before 2 hours and 24 hours after a marathon race. RESULTS: A total of 47 male runners with a wide range of body mass index (BMI) and fitness levels took part in the study. Baseline PWV was independent of body composition. Marathon running induced an acute PWV drop from 8.5 m/s to 7.9 m/s within the first two hours after the race (P < 0.05). Body composition and not physical fitness predicted the PWV differences postmarathon (P > 0.05). Changes in BP, heart rate, or inflammatory markers were not associated with PWV postmarathon. CONCLUSIONS: Though not evident at baseline, marathon running was associated with a reduced attenuation of central arterial stiffness in overweight and obese runners. The reduced responsiveness and attenuation of PWV with higher BMI, independent of hemodynamic changes and systemic inflammation, may represent masked vascular dysfunction in overweight and obese runners.

Effect of E-Bike Versus Bike Commuting on Cardiorespiratory Fitness in Overweight Adults: A 4-Week Randomized Pilot Study.

OBJECTIVE: To assess if active commuting with an electrically assisted bicycle (e-bike) during a 4-week period can induce increases in cardiorespiratory fitness measured as peak oxygen uptake (V[Combining Dot Above]O2peak) in untrained, overweight individuals, and if these changes are comparable with those induced by a conventional bicycle. DESIGN: Four-week randomized pilot study. SETTING: Controlled laboratory. PARTICIPANTS: Thirty-two volunteers (28 men) participated. Seventeen {median age 37 years [interquartile range (IQR) 34, 45], median body mass index [BMI] 29 kg/m [IQR 27, 31]} were randomized to the E-Bike group and 15 [median age 43 years (IQR 38, 45), median BMI 28 kg/m (IQR 26, 29)] to the Bike group. INTERVENTIONS: Participants in both groups were instructed to use the bicycle allocated to them (e-bike or conventional bicycle) for an active commute to work in the Basel (Switzerland) area at a self-chosen speed on at least 3 days per week during the 4-week intervention period. MAIN OUTCOME MEASURES: V[Combining Dot Above]O2peak was assessed before and after the intervention in an all-out exercise test on a bicycle ergometer. RESULTS: V[Combining Dot Above]O2peak increased by an average of 3.6 mL/(kg·min) [SD 3.6 mL/(kg·min)] in the E-Bike group and by 2.2 mL/(kg·min) [SD 3.5 mL/(kg·min)] in the Bike group, with an adjusted difference between the 2 groups of 1.4 mL/(kg·min) [95% confidence interval, -1.4-4.1; P = 0.327]. CONCLUSIONS: E-bikes may have the potential to improve cardiorespiratory fitness similar to conventional bicycles despite the available power assist, as they enable higher biking speeds and greater elevation gain.

Acute effects of interval versus continuous endurance training on pulse wave reflection in healthy young men.

AIM: Our aim was to investigate the acute and 24-hour (h) effects of high-intensity interval training (HIIT) and moderate continuous training (MCT) on arterial pulse wave reflection, an established marker of arterial stiffness and cardiovascular risk. METHODS: In a randomized cross-over design, 21 young healthy male participants performed a HIIT or a MCT on separate visits. Before and 5 (t5), 20 (t20), 35 (t35), and 50 (t50) minutes after the acute exercise bouts, the crude augmentation index (AIx) and the AIx at a set heart rate (AIx@75) were analysed by applanation tonometry. Starting 1 h post-exercise, both indices were captured over 24-h with an oscillometric monitoring device. RESULTS: AIx did not change significantly after MCT but declined progressively after HIIT, reaching significantly lower values compared to MCT at t35 (P = 0.045) and t50 (P = 0.008). AIx@75 increased after both acute exercise types but was higher after HIIT at t5 (P < 0.001), t20 (P < 0.001) and t35 (P = 0.009) compared to MCT. The 24-h follow-up revealed a significant decline in AIx@75 after HIIT (P = 0.007) but not after MCT (P = 0.813). CONCLUSIONS: Exercise intensity affects pulse wave reflection, with different time courses for AIx and AIx@75 post-exercise. Although initially higher after HIIT, AIx@75 declines in the 24-h recovery period indicating more favourable effects on pulse wave reflection compared to MCT. This may result in substantial positive chronic training effects on arterial stiffness in health and cardiovascular disease.