|HIIT-like 400m sprinting is exhausting, but unlike running to exhaustion and medium intensity steady state cardio it's not going to mess up your nervous system.|
Speaking of overtraining: As a SuppVersity reader you should actually be aware of the fact that scientists distinguish two different types of overtraining: Sympathetic and parasympathetic overtraining
Due to the fact that the symptoms (see Figure 1) closely resemble those Morbus Basedow (engl. Grave's Diseases) and Addison's Disease, respectively, sympathetic and parasympathetic overtraining are also called Basedowoid and Addisinoid overtraining.
|Figure 1: Overview of the symptoms of the two major forms of overtraining.|
read more). They will help you to check, where you're at, if you have a baseline reading that was taken, when you've been completely rested | learn more.For the average study participant in a recent experiment that was conducted by scientists from the , The 42nd Hospital of PLA, the Xinqiao Hospital and the Chongqing Normal University in China, the duration and intensity of their cardio workouts (running) determined, whether the prescribed workout routines that consisted of ...
There is such a thing as overtraining, folks | read more
- 30 minutes of running four times per week (moderate intensity group)
- 3 - 5x 1200 m runs per day with a 5-min break every 400 m four times per week (high intensity group)
If you have no idea what I am talking about, I suggest you take another look at my June 2012 article "Are You Still Burning Calories or Already Losing Fat? Study Shows: 5x15 Min HIIT Reduce Body Fat & Improve Fitness Twice as Effectively as 5x40min of Classic Cardio" (learn more) after you've finished this article.
- Heart rate variability (HRV): No significant changes in HRV parameters were found in all groups at pre and mid. But at post, the moderate intensity group showed more significant increases in RMSSD, PNN50, HF, LF and SDNN (P < 0.05 or 0.01) and much greater reduction in LF/HF than the other two groups (P was 0.033, 0.037 respectively). HFn of the moderate intensity group was significantly higher than that of the utmost intensity group (P = 0.012), while the opposite pattern occurred in LFn and LF/HF of the two groups (P was 0.025, 0.015 respectively).
As you would expect the changes in HRV in the moderate and utmost intensity group reflect increases in parasympathetic and sympathetic nervous system activity, respectively.
- Circadian Changes in Cold Pressor Test (CPT): From pre to post marked differences were not found in SBP and DBP of all groups and their increases. At post HR was much less increased in utmost intensity group during CPT than the other two groups (average P < 0.05).
Next to a high basal heart rate an inhibited increase in heart rate is another characteristic of later stages of sympathetic overtraining.
- Plasma catecholamine (NE & EPI): Norepinephrine (NE) concentration was considerably lower in utmost intensity group than the other two groups (P was 0.001, 0.00 respectively). At post marked inter-group differences were still not found in plasma PEI concentration.
A reduced catecholamine release is a classic characteristic of long(-er) term sympathetic overtraining - a phenomenon, some people may call "adrenal fatique" that occurs after an initial phase of catecholamine overproduction in sympathetic overtraining.
For the utmost intensity group, on the other hand, the scientists diagnosed an "over-excited SN [sympathetic nervous system]" (Tian. 2014), which is in contrast to the medium intensity and high intensity group, where the head-up tilt test did not indicate an "impairing effect on autonomic regulation" (Tian. 2014).
- Myslivecek, P.R., Brown, C.A. and Wolfe, L.A. (2002) Effects of Physical Conditioning on Cardiac Autonomic Function in Healthy Middle-Aged Women. Canadian Journal of Applied Physiology, 27, 1-18.
- Oosthuyse, T., & Avidon, I. (2014). Changes in substrate utilisation and protein catabolism during multiday cycling in well-trained cyclists. Journal of Sports Sciences, (ahead-of-print), 1-11.
- Pichot, V., Busso, T., Roche, F., Garet, M., Costes, F., Duverney, D., Lacour, J.R. and Barthélémy, J.C. (2002) Autonomic Adaptations to Intensive and Overload Training Periods: A Laboratory Study. Medicine & Science in Sports & Exercise, 34, 1660-1066.
- Tian, Kaixin, et al. "Effect of Endurance Training on the Autonomic Nervous System Function of Young Male." International Journal of Clinical Medicine 5.19 (2014): 1189.
- Yamamoto, K., Miyachi, M., Saitoh, T., Yoshioka, A. and Onodera, S. (2001) Effects of Endurance Training on Resting and Post-Exercise Cardiac Autonomic Control. Medicine & Science in Sports & Exercise, 33, 1496-1502.