Wiesław Pilis

The effect of a low-carbohydrate diet on performance, hormonal and metabolic responses to a 30-s bout of supramaximal exercise.

Abstract The aim of this study was to find out whether a low-carbohydrate diet (L-CHO) affects: (1) the capacity for all-out anaerobic exercise, and (2) hormonal and metabolic responses to this type of exercise. To this purpose, eight healthy subjects underwent a 30-s bicycle Wingate test preceded by either 3 days of a controlled mixed diet (130 kJ/kg of body mass daily, 50% carbohydrate, 30% fat, 20% protein) or 3 days of an isoenergetic L-CHO diet (up to 5% carbohydrate, 50% fat, 45% protein) in a randomized order. Before and during 1 h after the exercise venous blood samples were taken for measurement of blood lactate (LA), β-hydroxybutyrate (β-HB), glucose, adrenaline (A), noradrenaline (NA) and insulin levels. Oxygen consumption (V˙O2) was also determined. It was found that the L-CHO diet diminished the mean power output during the 30-s exercise bout [533 (7) W vs 581 (7) W, P < 0.05] without changing the maximal power attained during the first or second 5-s interval of the exercise. In comparison with the data obtained after the consumption of a mixed diet, after the consumption of a L-CHO diet resting plasma concentrations of β-HB [2.38 (0.18) vs 0.23 (0.01) mmol · l−1, P < 0.001] and NA [4.81 (0.68) vs 2.2 (0.31) nmol · l−1, P < 0.05] were higher, while glucose [4.6 (0.1) vs 5.7 (0.2) mmol · l−1, P < 0.05] and insulin concentrations [11.9 (0.9) vs 21.8 (1.8) mU · l−1] were lower. The 1-h post-exercise excess of V˙O2 [9.1 (0.25) vs 10.6 (0.25) l, P < 0.05], and blood LA measured 3 min after the exercise [9.5 (0.4) vs 10.6 (0.5) mmol · l−1, P < 0.05] were lower following the L-CHO treatment, whilst plasma NA and A concentrations reached higher values [2.24 (0.40) vs 1.21 (0.13) nmol · l−1 and 14.30 (1.41) vs 8.20 (1.31) nmol · l−1, P < 0.01, respectively]. In subjects on the L-CHO diet, the plasma β-HB concentration decreased quickly after exercise, attaining ≈30% of the pre-exercise value within 60 min, while insulin and glucose levels were elevated. The main conclusions of this study are: (1) a L-CHO diet is detrimental to anaerobic work capacity, possibly because of a reduced muscle glycogen store and decreased rate of glycolysis; (2) reduced carbohydrate intake for 3 days enhances activity of the sympathoadrenal system at rest and after exercise.

Effects of a brief Valsalva manoeuvre on hemodynamic response to strength exercises

Strength training is a recommended measure against loss of strength and muscle mass because of age‐ or illness‐induced inactivity. Strength exercises may impose heavy cardiovascular load by increasing heart rate and blood pressure. To increase strength efficiently, a heavy load has to be applied; this, however, leads to a spontaneous Valsalva manoeuvre, which additionally raises blood pressure. Avoidance of this manoeuvre is recommended. If the additional rise in arterial blood pressure caused by Valsalva manoeuvre is smaller than intrathoracic or intracranial pressures during this manoeuvre, Valsalva manoeuvre may actually protect arteries located in the thorax and in the brain by diminishing transmural pressure acting across these vessels. Effect of controlled breathing or brief Valsalva manoeuvre on arterial pressure at rest and during knee extension against 15‐repetition maximum resistance was evaluated. In 12 healthy young men blood pressure was measured continuously and non‐invasively, knee angle, speed of respiratory air or mouth pressure (MP) were continuously registered. Each combination of respiratory and exercise manoeuvres was repeated six times, for every of last three repetitions peak and trough systolic and diastolic pressure were determined. Strength exercises elevated peak pressures more than trough pressures, systolic more than diastolic. Valsalva manoeuvre increased only peak systolic and peak diastolic pressure. This increase was in average lesser than MP, thus rendering an argument in favour of protective role of brief Valsalva manoeuvre because of decline in transmural pressure acting on thoracic and possibly cerebral arteries. However, there was strong individual variability, and in few instances, arterial pressure increased because of brief Valsalva manoeuvre more than MP; thus in some subjects, the manoeuvre might enhance transmural pressure acting on thorax arteries.

Evaluation of the Blood Antioxidant Capacity in Two Selected Phases of the Training Cycle in Professional Soccer Players

Evaluation of the Blood Antioxidant Capacity in Two Selected Phases of the Training Cycle in Professional Soccer Players The aim of this study was to evaluate the effects of a regular pre-season training on the aerobic performance and the blood antioxidant defense capacity in soccer players from the Polish Premier League club (n=19) and IVth League team (n=15). The players participated in an incremental treadmill running exercise to volitional fatigue twice (i.e., at the beginning (Trial A) and the end (Trial B) of the pre-season spring training). In venous blood samples, taken at rest and 3 min post-test, the activities of antioxidant enzymes (SOD, GSH-Px, CAT, GR) and concentrations of non-enzymatic antioxidants (GSH, tocopherols, retinol, uric acid) and malondialdehyde as a lipid peroxidation biomarker were measured. With the aim of between-group comparisons and possible conclusions on training-induced changes in the capacity of the blood antioxidant defense, the POTAX index was calculated as a sum of standardized activities of antioxidant enzymes and concentrations of non-enzymatic antioxidants. The results of the present study indicate that the players from the Premier League club were characterized by only slightly higher maximal oxygen uptake rates, the differences compared to IVth League team, as assessed in both trials, were statistically insignificant. Participation in the pre-season training resulted in a moderate improvement of aerobic performance, although only a few players were characterized by VO2max comparable to the international-class elite performers. No distinct differences were observed in the level of aerobic performance between higher- and lower-classified players. Pre-season training led to an improvement in the global blood antioxidant capacity expressed in terms of POTAOX indices, although the changes in the activities and concentrations of individual components of the antioxidant system were less pronounced. Training-induced level of antioxidant conditioning was higher among the Premier League players, which may be related to differences in the training schedule and nutritional preparation of the athletes.

INFLUENCE OF COMPLEX PHYSIOTHERAPY ON THE FUNCTIONAL CONDITION OF THE SPINE IN OLDER PEOPLE

The aim of the present study was to assess the impact of 21-days comprehensive physiotherapy program on the functional condition of the spine and severity of pain in older people. To achieve this goal, physiotherapeutic procedures were performed on 100 elderly patients suffering from spinal disorders. The comprehensive therapy program consisted of: general improvement exercises, individual exercises with a physiotherapist, exercises in water and physical therapy treatments such as: TENS currents, galvanic current, iontophoresis, laser stimulation, magnetic field on the lumbar spine and hydro massage or mud compresses. Prior and post the therapy program: the Schober’s test 1 (forward flexion), Schober’s test 2 (extension), Ott’s test, fingertip-to-floor (FTF) test, pain Visual Analogue Scale (VAS) and the modified Oswestry low back pain questionnaire were evaluated. Statistically significant improvement (p<0.001) in all tested parameters was shown at the end of therapy program. Age, height, body weight and body mass index (BMI) has no impact on results before and after the physiotherapy program in respective tests. In conclusion, the conducted study has shown the effectiveness of applied comprehensive physiotherapy program on the functional condition of Sarzyńska-Długosz et al., 2018. Influence of Complex Physiotherapy on the Functional Condition of the Spine in Older People 243 the spine and improvement of the quality of life of the treated patients, regardless of their somatic conditions.

BACK PAIN CHARACTERISTICS IN PHYSICAL AND OFFICE WORKERS

The aim of our study was to characterize back pain according to the occupation comprising physical and office work. Accordingly questionnaires from 100 physical workers (PW) and 100 office workers (OW) were collected. This dedicated questionnaire included 19 questions, of which 7 concerned demographic, work and stature features and 12 concerned back pain. Collected data showed that lower back pain was more common in PW but cervical pain in OW (p<0.001). Most common aetiology of back pain was spinal osteoarthritis, sciatica and scoliosis but of different spread in two groups (p<0.001). The history of back pain was most often above 5 years and there were significant differences in frequency, intensity and pain handling methods between groups (p<0.005). Back pain prophylaxis was well acknowledged in both groups (85 % in OW, 91 % in PW). Regular physical activity was considered the main prophylaxis method (67 % in PW, 89 % in OW) and similarly incorporated in both groups (p=0.691) however OW more often performed physical exercises (p<0.001). Physical therapy was used in both groups (PW 100 %, OW 92 %, p=0.004) but with variable efficacy according to responders. To conclude there were multiple differences between both groups in terms of the pain characteristic but with similar awareness and incorporated prophylaxis.