Vagal Response to 15-weeks of High-Intensity Functional Training: A Pilot Study

Brian Kliszczewicz, Yuri Feito, Dierdra Bycura, Danielle Brown, Brandi Price


The purpose of this investigation was to examine the training effects of a 15-week High-Intensity Functional Training (HIFT) on Autonomic Nervous System (ANS). Eleven apparently healthy college students participated in this study. Participants were enrolled in a 15-week CrossFit® training based academic course, two days a week. On the first and last scheduled day of class participants performed a HIFT trial and ANS activity was measured through Heart Rate Variability (HRV) for 10 minutes prior to and following each bout using the log-transformed square root of the successive R-R differences (lnRMSSD) and high frequency power (lnHF). A significant decreased was observed for the lnRMSSD after the HIFT trial before (Pre: 3.86 ± 0.39 vs. Post: 2.58 ± 1.12; P < 0.001) and after (Pre: 4.00 ± 0.46 vs. 1.96 ± 0.84; P < 0.001) the intervention.  Similarly, the lnHF was significantly reduced before (Pre: 3.66 ± 0.36 vs. Post: 2.88 ± 0.86; P < 0.05) and after (Pre: 3.73 ± 0.41 vs. 2.69 ± 0.65; P < 0.001) 15-weeks of this intervention. The exercise modality known as HIFT was effective in improving repetitions completed during the HIFT trial, when comparing pre and post trials. The findings of this study suggest that resting HRV and post exercise vagal reactivation is not influenced by 15-weeks of a HIFT intervention.


Heart Rate Variability; CrossFit; Exercise

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Thompson W. Worldwide Survey of Fitness Trends For 2015: What’s Driving the Market. ACSM’s Health & Fitness Journal. 2014 Dec;18(6):8–17.

Roy BA. FUNctional Exercise Training: ACSMs Health Fit J. 2014;18(3):3.

Borresen J, Lambert PMI. Autonomic Control of Heart Rate during and after Exercise. Sports Med. 2012 Oct 7;38(8):633–46.

Buchheit M, Papelier Y, Laursen PB, Ahmaidi S. Noninvasive assessment of cardiac parasympathetic function: postexercise heart rate recovery or heart rate variability? Am J Physiol - Heart Circ Physiol. 2007 Jul 1;293(1):H8–10.

Stanley J, Peake JM, Buchheit M. Cardiac Parasympathetic Reactivation Following Exercise: Implications for Training Prescription. Sports Med. 2013 Aug 3;43(12):1259–77.

Malik M. Heart Rate Variability. Ann Noninvasive Electrocardiol. 1996 Apr 1;1(2):151–81.

Hautala AJ, Mäkikallio TH, Kiviniemi A, Laukkanen RT, Nissilä S, Huikuri HV, Tulppo MP. Cardiovascular autonomic function correlates with the response to aerobic training in healthy sedentary subjects. Am J Physiol Heart Circ Physiol. 2003 Oct;285(4):H1747-1752.

Hedelin R, Bjerle P, Henriksson-Larsén K. Heart rate variability in athletes: relationship with central and peripheral performance. Med Sci Sports Exerc. 2001 Aug;33(8):1394–8.

Kliszczewicz BM, Esco MR, Quindry JC, Blessing DL, Oliver GD, Taylor KJ, Price BM. Autonomic Responses to an Acute Bout of High-Intensity Body Weight Resistance Exercise vs. Treadmill Running: J Strength Cond Res. 2016 Apr;30(4):1050–8.

Bond B, Cockcroft EJ, Williams CA, Harris S, Gates PE, Jackman SR, Armstrong N, Barker AR. Two weeks of high-intensity interval training improves novel but not traditional cardiovascular disease risk factors in adolescents. Am J Physiol - Heart Circ Physiol. 2015 Sep 15;309(6):H1039–47.

Tian Y, Huang C, He Z, Hong P, Zhao J. Autonomic function responses to training: Correlation with body composition changes. Physiol Behav. 2015 Nov 1;151:308–13.

Glassman G. Understanding CrossFit by Greg Glassman [Internet]. CrossFit Journal. [cited 2016 Apr 19]. Available from:

Pescatello L. ACSM’s Guidelines for Exercise Testing and Prescription. 9th ed. 351 West Camdem Street Baltimore, MD, 21201: Lippincott Williams & Wilkins; 2014.

Goldberger JJ, Le FK, Lahiri M, Kannankeril PJ, Ng J, Kadish AH. Assessment of parasympathetic reactivation after exercise. Am J Physiol - Heart Circ Physiol. 2006 Jun 1;290(6):H2446–52.

Esco MR, Flatt A. Ultra-Short-Term Heart Rate Variability Indexes at Rest and Post-Exercise in Athletes: Evaluating the Agreement with Accepted Recommendations. J Sports Sci Med. 2014 Jan 9;13(3):535–41.

Billman GE. The LF/HF ratio does not accurately measure cardiac sympatho-vagal balance. Front Physiol [Internet]. 2013 [cited 2016 Apr 1];4. Available from:

Kiviniemi AM, Hautala AJ, Kinnunen H, Tulppo MP. Endurance training guided individually by daily heart rate variability measurements. Eur J Appl Physiol. 2007 Sep 12;101(6):743–51.

Parekh A, Lee CM. Heart Rate Variability after Isocaloric Exercise Bouts of Different Intensities: Med Sci Sports Exerc. 2005 Apr;37(4):599–605.

Heffernan KS, Kelly EE, Collier SR, Fernhall B. Cardiac autonomic modulation during recovery from acute endurance versus resistance exercise. Eur J Cardiovasc Prev Rehabil. 2006 Feb 1;13(1):80–6.

Chen J-L, Yeh D-P, Lee J-P, Chen C-Y, Huang C-Y, Lee S-D, Chen C-C, Kuo TB, Kao C-L, Kuo C-H. Parasympathetic Nervous Activity Mirrors Recovery Status in Weightlifting Performance After Training: J Strength Cond Res. 2011 Jun;25(6):1546–52.

Melanson EL, Freedson PS. The effect of endurance training on resting heart rate variability in sedentary adult males. Eur J Appl Physiol. 2001 Sep;85(5):442–9.

Cornelissen VA, Verheyden B, Aubert AE, Fagard RH. Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability. J Hum Hypertens. 2009 Jun 25;24(3):175–82.

Catai AM, Chacon-Mikahil MPT, Martinelli FS, Forti V a. M, Silva E, Golfetti R, Martins LEB, Szrajer JS, Wanderley JS, Lima-Filho EC, Milan LA, Marin-Neto JA, Maciel BC, Gallo-Junior L. Effects of aerobic exercise training on heart rate variability during wakefulness and sleep and cardiorespiratory responses of young and middle-aged healthy men. Braz J Med Biol Res. 2002 Jun;35(6):741–52.

Murray NP, Raedeke TD. Heart rate variability as an indicator of pre-competitive arousal. Int J Sport Psychol. 2008;39(4):346–55.

Kannankeril PJ, Goldberger JJ. Parasympathetic effects on cardiac electrophysiology during exercise and recovery. Am J Physiol - Heart Circ Physiol. 2002 Jun 1;282(6):H2091–8.

Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max: Med Amp Sci Sports Amp Exerc. 1996 Oct;28(10):1327–30.

Seynnes OR, Boer M de, Narici MV. Early skeletal muscle hypertrophy and architectural changes in response to high-intensity resistance training. J Appl Physiol. 2007 Jan 1;102(1):368–73.



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