scholarly journals The effects of varying doses of caffeine on cardiac parasympathetic reactivation following an acute bout of anaerobic exercise in recreational athletes

Author(s):  
Amir Sarshin ◽  
Alireza Naderi ◽  
Carlos Janssen Gomes da Cruz ◽  
Foad Feizolahi ◽  
Scott C. Forbes ◽  
...  
2020 ◽  
Author(s):  
Amir Sarshin ◽  
Alireza Naderi ◽  
Carlos Janssen Gomes da Cruz ◽  
Foad Feizolahi ◽  
Scott C. Forbes ◽  
...  

Abstract Background: To examine the effects of varying doses of caffeine on autonomic reactivation following anaerobic exercise. Methods: Recreationally active males (N=20; 24±2y) participated in a randomized, double-blind, placebo-controlled, crossover study where participants ingested: (1) Control (CON; no supplement), (2) a non-caffeinated placebo (PLA), (3) 3-mg∙kg-1 of caffeine (CAF3) or (4) 6-mg∙kg-1 of caffeine (CAF6) prior to Wingate testing. Parasympathetic (lnRMSSD, primary outcome) and global HRV (lnSDNN, secondary outcome) were assessed at rest (i.e., pre-ingestion), 45-min post-ingestion, and 5-min and 35-min post-exercise recovery. We used a GLM to assess mean (95% CI) changes from pre-ingestion baseline.Results: Overall, we observed a significant trend for lnRMSSD and lnSDNN (both, p=0.001, ηp2=0.745). Forty-five minutes after treatment ingestion, we observed a significant increase in lnRMSSD for CAF3 (0.15ms, 95%CI, 0.07,0.24) and CAF6 (0.16ms, 95%CI, 0.06,0.25), both being significant (both, p<0.004) vs. CON (-0.02ms, 95%CI, -0.09,0.04). Five-minutes after exercise, all treatments demonstrated significant declines in lnRMSSD vs. baseline (all, p<0.001). After 35-min of recovery, lnRMSSD returned to a levels not significantly different than baseline for CAF3 (0.03ms, 95%CI, -0.05, 0.12) and CAF6 (-0.03ms, 95%CI, -0.17, 0.10), while PLA (-0.16ms, 95%CI, -0.25, -0.06) and CON (-0.17ms, 95%CI, -0.28, -0.07) treatments remained significantly depressed. A similar pattern was also observed for SDNN.Conclusion: Caffeine ingestion increases resting cardiac autonomic modulation and accelerates post-exercise autonomic recovery after a bout of an anaerobic exercise test in recreationally active young men. However, no differences between caffeine doses on cardiac autonomic reactivity were observed.


2020 ◽  
Author(s):  
Amir Sarshin ◽  
Alireza Naderi ◽  
Carlos Janssen Gomes da Cruz ◽  
Foad Feizolahi ◽  
Scott C. Forbes ◽  
...  

Abstract Background: To examine the dose effects of caffeine ingestion on autonomic reactivation following anaerobic exercise. Methods: Recreationally active males (N=20; 24±2y) participated in a randomized, double-blind, placebo-controlled, crossover study where participants ingested: (1) Control (CON; no supplement), (2) a non-caffeinated placebo (PLA), (3) 3-mg∙kg-1 of caffeine (CAF3) or (4) 6-mg∙kg-1 of caffeine (CAF6) prior to a Wingate testing. Parasympathetic (lnRMSSD, primary outcome) and global HRV (lnSDNN, secondary outcome) were assessed at rest (i.e., pre-ingestion), 45-min post-ingestion, and 5-min and 35-min post-exercise recovery. We used a GLM to assess mean (95% CI) changes from pre-ingestion baseline.Results: Overall, we observed a significant trend for lnRMSSD and lnSDNN (both, p=0.001, ηp2=0.745). Forty-five minutes after treatment ingestion, we observed a significant increase in lnRMSSD for CAF3 (0.15ms, 95%CI, 0.07,0.24) and CAF6 (0.16ms, 95%CI, 0.06,0.25), both being significant (both, p<0.004) vs. CON (-0.02ms, 95%CI, -0.09,0.04). Five-minutes after exercise, all treatments demonstrated significant declines in lnRMSSD vs. baseline (all, p<0.001). After 35-min of recovery, lnRMSSD returned to a levels not significantly different than baseline for CAF3 (0.03ms, 95%CI, -0.05, 0.12) and CAF6 (-0.03ms, 95%CI, -0.17, 0.10), while PLA (-0.16ms, 95%CI, -0.25, -0.06) and CON (-0.17ms, 95%CI, -0.28, -0.07) treatments remained significantly depressed. A similar pattern was also observed for SDNNConclusion: Caffeine ingestion increases resting cardiac autonomic modulation and accelerates post-exercise autonomic recovery after a bout of anaerobic exercise test in recreationally active young men. However, no differences between caffeine doses on cardiac autonomic reactivity were observed.


Author(s):  
Cristina Vassalle ◽  
Serena Del Turco ◽  
Laura Sabatino ◽  
Giuseppina Basta ◽  
Maristella Maltinti ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 879
Author(s):  
Robert D. Crapnell ◽  
Ascanio Tridente ◽  
Craig E. Banks ◽  
Nina C. Dempsey-Hibbert

Lactate is widely measured in critically ill patients as a robust indicator of patient deterioration and response to treatment. Plasma concentrations represent a balance between lactate production and clearance. Analysis has typically been performed with the aim of detecting tissue hypoxia. However, there is a diverse range of processes unrelated to increased anaerobic metabolism that result in the accumulation of lactate, complicating clinical interpretation. Further, lactate levels can change rapidly over short spaces of time, and even subtle changes can reflect a profound change in the patient’s condition. Hence, there is a significant need for frequent lactate monitoring in critical care. Lactate monitoring is commonplace in sports performance monitoring, given the elevation of lactate during anaerobic exercise. The desire to continuously monitor lactate in athletes has led to the development of various technological approaches for non-invasive, continuous lactate measurements. This review aims firstly to reflect on the potential benefits of non-invasive continuous monitoring technology within the critical care setting. Secondly, we review the current devices used to measure lactate non-invasively outside of this setting and consider the challenges that must be overcome to allow for the translation of this technology into intensive care medicine. This review will be of interest to those developing continuous monitoring sensors, opening up a new field of research.


Author(s):  
Mette Wærstad Hansen ◽  
Stein Ørn ◽  
Christine B. Erevik ◽  
Magnus Friestad Bjørkavoll-Bergseth ◽  
Øyvind Skadberg ◽  
...  

Abstract Background Dietary supplement use among recreational athletes is common, with the intention of reducing inflammation and improving recovery. We aimed to describe the relationship between omega-3 fatty acid supplement use and inflammation induced by strenuous exercise. Methods C-reactive protein (CRP) concentrations were measured in 1002 healthy recreational athletes before and 24 h after a 91-km bicycle race. The use of omega-3 fatty acid supplements was reported in 856 out of 1002 recreational athletes, and the association between supplement use and the exercise-induced CRP response was assessed. Results Two hundred seventy-four subjects reported regular use of omega-3 fatty acid supplements. One hundred seventy-three of these used cod liver oil (CLO). Regular users of omega-3 fatty acid supplements had significantly lower basal and exercise-induced CRP levels as compared to non-users (n = 348, p < 0.001). Compared to non-users, regular users had a 27% (95% confidence interval (CI): 14–40) reduction in Ln CRP response (unadjusted model, p < 0.001) and 16% (95% CI: 5–28, p = 0.006) reduction after adjusting for age, sex, race duration, body mass index, delta creatine kinase, MET hours per week, resting heart rate and higher education. CLO was the primary driver of this response with a 34% (95% CI: 19–49) reduction (unadjusted model, p < 0.001) compared to non-users. Corresponding numbers in the adjusted model were 24% (95% CI: 11–38, p < 0.001). Conclusion Basal CRP levels were reduced, and the exercise-induced CRP response was attenuated in healthy recreational cyclists who used omega-3 fatty acid supplements regularly. This effect was only present in regular users of CLO. Trial registration NCT02166216, registered June 18, 2014 – Retrospectively registered.


Endocrines ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 79-90
Author(s):  
Johanna K. Ihalainen ◽  
Ida Löfberg ◽  
Anna Kotkajuuri ◽  
Heikki Kyröläinen ◽  
Anthony C. Hackney ◽  
...  

Sex hormones are suggested to influence energy intake (EI) and metabolic hormones. This study investigated the influence of menstrual cycle (MC) and hormonal contraceptive (HC) cycle phases on EI, energy availability (EA), and metabolic hormones in recreational athletes (eumenorrheic, NHC = 15 and monophasic HC-users, CHC = 9). In addition, 72-h dietary and training logs were collected in addition to blood samples, which were analyzed for 17β-estradiol (E2), progesterone (P4), leptin, total ghrelin, insulin, and tri-iodothyronine (T3). Measurements were completed at four time-points (phases): Bleeding, mid-follicular (FP)/active 1, ovulation (OVU)/active 2, mid-luteal (LP)/inactive in NHC/CHC, respectively. As expected, E2 and P4 fluctuated significantly in NHC (p < 0.05) and remained stable in CHC. In NHC, leptin increased significantly between bleeding and ovulation (p = 0.030) as well as between FP and OVU (p = 0.022). No group differences in other measured hormones were observed across the MC and HC cycle. The mean EI and EA were similar between phases, with no significant differences observed in macronutrient intake over either the MC or HC. While the MC phase might have a small, but statistically significant effect on leptin, the findings of the present study suggest that the MC or HC phase does not significantly alter ad libitum EI or EA in recreational athletes.


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