PhD, Associate Professor A.B. Miroshnikov¹
PhD, Associate Professor P.N. Levashov¹
PhD, Associate Professor A.V. Tarasov¹
Postgraduate A.D. Formenov^1
1Russian State University of Physical Education, Sports, Youth and Tourism (SCOLIPE), Moscow

Keywords: physical rehabilitation, arterial blood pressure, powerlifting, interval training.

Background. Arterial hypertension, often referred to as the "silent killer", is the most common abnormal diagnosis in athletes from strength sports. It is a well-known fact that strength sports representatives have a high percentage of muscle mass [3], which should positively affect their metabolic status [6]. The skeletal muscle fibers are divided into two main categories: oxidative muscle fibers and glycolytic muscle fibers. Such a working muscle composition may affect the strength and speed qualities [11], ability to effectively recover after physical activity [7], and blood pressure [5]. The metabolic characteristics of the muscle fibers (oxidizing potential, capillarization, and mitochondrial mass) change under training loads. As a result, a high percentage of oxidative muscle fibers in the skeletal muscles is one of the main predictors of the low blood pressure rates [4]. The high body mass index (BMI) is also associated with cardiovascular diseases, an increase in premature mortality, and a 30% higher risk of death from all causes, with an increase in BMI for every 5 kg/m² [9]. Accordingly, any reduction in BMI will lead to the prevention of cardiovascular diseases and an increase in life expectancy. Other studies showed that it is the excess subcutaneous adipose tissue that is strongly associated with the mortality rate due to cardiovascular diseases and all-cause mortality [8]. Later, Colpitts et al. [2] indicated that: 1) BMI is a strong predictor of the development of metabolic syndrome (with arterial hypertension as its factor); 2) to prevent further cardiometabolic risk, attention should be paid to the muscle quality (the growth of the oxidizing potential) rather than to the greater muscle gains. Several meta-analyses (Keating S.E., 2017; Wewege M., 2017) revealed that high intensity aerobic training (High Intensity Interval Training (HIIT)) can be an effective component of the body composition correction programs. Moreover, the meta-analysis of Viana et al. showed that it is HIIT that contributes to the reduction of the total fat mass by 28.5% as opposed to continuous aerobic training [10]. Besides, recent systematic reviews and meta-analyses (Costa E.C., 2018; Way K.L., 2019) showed that: 1) HIIT and continuous aerobic training (moderate-intensity continuous training) lead to a consistent decrease of blood pressure at rest in adults provisionally diagnosed with arterial hypertension; 2) HIIT is associated with a greater increase in maximal oxygen consumption (MOC) as opposed to moderate-intensity continuous training; 3) HIIT results in a significant reduction in the nighttime diastolic blood pressure as opposed to moderate-intensity continuous training; 4) HIIT leads to a greater decrease of the daytime blood pressure as opposed to moderate-intensity continuous training. At the same time, the effects that reduce blood pressure after trainings are more pronounced in those with a higher baseline blood pressure rate and under the influence of HIIT as opposed to the moderate-intensity continuous training [1]. However, it has not yet been established what is the main therapeutic factor in the blood pressure reduction, reduction of body weight (fat component), or cardio-respiratory and metabolic adaptation caused by HIIT.

Objective of the study was to conduct a comparative analysis of the effects of the growth of oxidizing potential of the working muscles and changes in the body composition on the blood pressure rates in hypertensive athletes from strength sports.

Methods and structure of the study. The study was carried out on the basis of the Sports Medicine Department of the Russian State University of Physical Education, Sport, Youth, and Tourism (RSUPESYT). Sampled for the study were 55 representatives of strength sports (powerlifters) of different qualifications (CMS, MS) and of heavy weight categories only (body weight - 101.4±5.3 kg). The athletes were randomly divided into two groups: Experimental (n=35) and Control (n=20). The mean age of the male athletes was 31.0±7.3 years. As required by the ethical standards in scientific research in the physical culture and sports sector in 2020, all subjects gave their voluntary written informed consent to participate in the study (extract from Protocol No. 5, meeting of the Ethics Committee of FSBEI HE "RSUPESYT" of 26.10.2017). The tasks set forth in the study were fulfilled using the following research methods: interview, inspection, 3-time blood pressure measurement, bioimpedansometry (bioelectrical impedance analysis), gasometric analysis, and mathematical statistics methods. Bioimpedansometry was performed using the "Medass - ABC-02" device (Russia) and was aimed to measure subcutaneous adipose tissue (%) and BMI (kg/m²). The step load test was performed on the cycle ergometer "MONARK 839 E" (Monark AB, Sweden). The initial load equaled 25 W, every 2 minutes the load increased by 20 W. The gasometric analysis was carried out using the gas analyzer "CORTEX" (Meta Control 3000, Germany) aimed to measure oxygen consumption and carbon dioxide emissions every inhale-exhale cycle. Heart rate and R-R intervals were registered using the heart rate monitor "POLAR RS800" (Finland). The test was performed at a rate of 75 revolutions×min-1 until MOC and AnT were registered. The study also included self-monitoring of blood pressure according to the clinical guidelines developed by the Russian Medical Society on Arterial Hypertension (RMSAH) and approved at the session of the Plenum on November 28, 2013, and the Special-Purpose Cardiology Committee on November 29, 2013. The certified traditional automatic household tonometers were used for self-monitoring of blood pressure. Blood pressure was measured in the morning (7-8 a.m.). The subjects took 3 measurements with a minimum of 1-minute interval on the left hand. All the blood pressure rates were recorded in the table, the mean values were recorded in the archival data. The Experimental Group athletes were trained for 120 days (3 times a week) in accordance with the following protocol: the traditional strength training system was supplemented by the aerobic load (training on a cycle ergometer, 7 high-intensity intervals (with the pedaling power of 100% of MOC), 2 minutes each, and a low-intensity interval with the heart rate at the level of 85% of AnT, 2 minutes. The HIIT session lasted 28 minutes. The Control Group athletes were trained for 120 days (3 times a week) in accordance with the traditional strength training protocol.

Results and discussion. The 120-day intervention reduced the subcutaneous adipose tissue rates in the Experimental Group athletes by 2.6% and their BMI - by 0.7 kg/m² (p<0.05). In the Control Group, these indicators did not change statistically significantly. Also, after 120 days of physical rehabilitation, the BR rates in the Experimental Group athletes decreased significantly: systolic blood pressure - by 4.7% and diastolic blood pressure - by 5.6% (p<0.05). In the Control Group, the blood pressure rates did not change statistically significantly (Table 1).

Table 1. Comparative analysis of blood pressure and body composition rates in athletes from strength sports

Table 2. Gasometric test rates in athletes from strength sports

References

1. Clark T., Morey R., Jones M.D., Marcos L., Ristov M., Ram A., … Keech A. (2020). High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity. Hypertension Research. doi:10.1038/s41440-019-0392-6.
2. Colpitts B.H., Bouchard D.R., Keshavarz M., Boudreau J., & Sénéchal M. (2019). Does Lean Body Mass Equal Health Despite Body Mass Index? Scandinavian Journal of Medicine & Science in Sports. doi:10.1111/sms.13605.
3. Guo J., Lou Y., Zhang X., Song Y. (2015) Effect of aerobic exercise training on cardiometabolic risk factors among professional athletes in the heaviest-weight class. Diabetol Metab Syndr.doi: 10.1186/s13098-015-0071.
4. Hernelahti M., Tikkanen H.O., Karjalainen J., Kujala U.M. (2005). Muscle Fiber-Type Distribution as a Predictor of Blood Pressure: A 19-Year Follow-Up Study. Hypertension, 45(5), 1019–23. doi:10.1161/01.hyp.0000165023.09921.34.
5. Houmard J.A., Weidner M.L., Koves T.R., Hickner R.C., Cortright R.L. (2000). Association between muscle fiber composition and blood pressure levels during exercise in men. American Journal of Hypertension, 13(6), 586–592. doi:10.1016/s0895-7061(99)00259-9.
6. Li R., Xia J., Zhang X.I., Gathirua-Mwangi W.G., Guo J., Li Y., McKenzie S., Song Y. Prevalence of metabolic syndrome and its components among Chinese professional athletes of strength sports with different body weight categories. PLoS One. 2013;8: 1-7.
7. Lievens E., Klass M., Bex T., Derave W. (2020). Muscle fiber typology substantially influences time to recover from high-intensity exercise. Journal of Applied Physiology. doi:10.1152/japplphysiol.00636.2019.
8. Ortega F.B., Sui X., Lavie C.J., Blair S.N. (2016). Body Mass Index, the Most Widely Used But Also Widely Criticized Index. Mayo Clinic Proceedings, 91(4), 443–455. doi:10.1016/j.mayocp.2016.01.008.
9. Prospective Studies Collaboration. (2009). Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. The Lancet, 373(9669), 1083–1096. doi:10.1016/s0140-6736(09)60318-4.
10. Viana R.B., Naves J.P.A., Coswig V.S., de Lira C.A.B., Steele J., Fisher J.P., Gentil P. (2019). Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT). British Journal of Sports Medicine, bjsports–2018–099928. doi:10.1136/bjsports-2018-099928.
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Corresponding author: benedikt116@mail.ru

Abstract

Objective of the study was to conduct a comparative analysis of the effects of the growth of oxidizing potential of the working muscles and changes in the body composition on the BP rates in hypertensive athletes from strength sports.

Methods and structure of the study. The study involved 55 strength sports representatives (powerlifters) of different qualifications (CMS, MS) and of heavy weight categories only (body weight - 101.4±5.3 kg). The athletes were randomly divided into two groups: Experimental (n=35) and Control (n=20). The mean age of the male athletes was 31.0±7.3 years. The Experimental Group athletes were trained for 120 days (3 times a week) in accordance with the following protocol: the traditional strength training system was supplemented by the aerobic load (training on a cycle ergometer, 7 high-intensity intervals (with the pedaling power of 100% of MOC), 2 minutes each, and a low-intensity interval with heart rate at the level of 85% of AnT, 2 minutes. The high intensity interval training (HIIT) session lasted 28 minutes. The Control Group athletes were trained for 120 days (3 times a week) in accordance with the traditional strength training protocol.

Results and conclusion. The study found that the 120-day physical rehabilitation led to the reduction of the fat mass in the hypertensive athletes of heavy weight categories. A well-known body mass index (or subcutaneous adipose tissue) reduction strategy, causing significant changes in blood pressure, can be achieved through dietary interventions only, without physical exercise. However, we proved that HIIT, apart from the athlete’s body composition, has a therapeutic and prophylactic effect on the cardiovascular system. The aerobic training protocol we developed based on the metabolic variables will help athletes to effectively and safely influence the prevention and treatment of AH. A further priority area is pedagogical work among athletes from strength sports aimed to include aerobic cycling trainings in the training protocols.