Key result
Higher serum CK release during intensified training correlates with reduced parasympathetic HRV.
Why the study?
The relationship between morning heart rate variability and creatine kinase response during intensified training in recreational endurance athletes was not well characterized.
Does a period of intensified cycling training alter morning heart rate variability and creatine kinase response in recreational endurance athletes?
Observational (n=12)
No
Does a period of intensified cycling training alter morning heart rate variability and creatine kinase response in recreational endurance athletes?
Cardiac autonomic control at morning rest correlates with serum creatine kinase release during intensified training, suggesting its utility for monitoring training load.
May support morning HRV monitoring of training load in endurance athletes; hypothesis-generating and requires prospective validation before clinical use.
Specific physiological responses and their relationship were analyzed in 12 recreational endurance athletes (43.8 ± 7.9 years) during a period of intensified cycling training. Heart rate (HR), HR variability (HRV), serum creatine kinase (S-CK) and haematocrit (Hct) were measured in the mornings before (PRE) and following three consecutive days of intensified training (POST 1-3). Morning HR increased during this period (PRE: 52.2±6.7 bpm, POST 1: 58.8±7.0 bpm POST 2: 58.5±8.1 bpm, POST 3: 57.9±7.2 bpm; F(3,33) = 11.182, p < 0.001, ηp2 = 0.554). Parasympathetic HRV indices decreased from PRE to POST (F(3,33) ≥ 11.182, p < 0.001, ηp2 ≥ 0.563), no effect was found for sympathetically modulated HRV (F(3,33) = 2.287, p = 0.101, ηp2 = 0.203). Hct decreased (PRE: 49.9±4.0%, POST 1: 46.5±5.1%, POST 2: 45.5±3.8%, POST 3: 43.2±3.4%; F(3,33) = 11.909, p < 0.001, ηp2 = 0.520) and S-CK increased during the training period (PRE: 90.0±32.1 U/L, POST 2: 334.7±487.6 U/L, POST 3: 260.1±303.4 U/L, POST 3: 225.1±258.8 U/L; (F(3,33) = 3.996, p = 0.017, ηp2 = 0.285). S-CK release was associated with HR (r = 0.453, p = 0.002, n = 44), RMSSD (r= -0.494, p= 0.001, n = 44) and HF-Power (r = -0.490, p = 0.001, n = 44). A period of intensified training was associated with haemodilution, parasympathetic withdrawal and S-CK-increase. Cardiac autonomic control at morning rest correlated with the S-CK-release; and thus, may serve as a practical mean to complementary monitor and prescribe training load in this population.
No takes yet. Share an insight, caveat, or question.
Weippert et al. (2018) conducted an observational in Healthy recreational endurance athletes (n=12). Intensified cycling training vs. Baseline (PRE) was evaluated on Correlation between morning heart rate variability (RMSSD) and serum creatine kinase (S-CK) response (r = -0.494, p=0.001). During a period of intensified training in recreational endurance athletes, serum creatine kinase release was significantly correlated with reduced parasympathetic heart rate variability (RMSSD r = -0.494, p = 0.001).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: