Thomas Abel

EEG activity and mood in health orientated runners after different exercise intensities.

An increasing number of studies within the recent years connected physical exercise with changes in brain cortical activity. Most of this data (1) refers to aerobic exercise and (2) does not correlate to psychological parameters although it is well known that exercise has a positive effect on mood. In times where health activities play a major role it is increasingly necessary to connect somato-physiological and somatopsychological components of physical activity. This study aimed to find changes in EEG activity and mood after low, preferred and high intensity running. EEG and actual state of mood were recorded before and after exercise. Results showed an effect for the preferred and high intensity velocity in both, EEG and mood. As only the higher frequency areas N18 Hz showed persisting decreases post-exercise we concluded that this might be a sign of outlasting effects of exercise on brain cortical activity which may have influences on general well-being. We could also show that there is a clear relationship between EEG activity and mood reflecting a basic principle of cortical excitation.

Energy expenditure in ball games for wheelchair users.

Purpose:Wheelchair sports have become popular in Germany. This is important because of the difficulty experienced by wheelchair-dependent people in maintaining cardiovascular health and fitness by daily activities. Increasing energy expenditure (EE; kcal h−1) is one of the most effective ways of decreasing risk of cardiovascular disease. The purpose of this study was to evaluate the EE of individuals with spinal cord injury in ball games for wheelchair-dependent persons.Methods:Fourteen tennis players (WT), 10 basketball players (WB) and 12 rugby players (WR) completed a basal metabolism evaluation and a training test to measure respiratory parameters.Results:In the basal metabolism test EE in WT was 66.8±12.8 kcal h−1, in WB 62.7±15.0 kcal h−1 and in WR 63.5±12.9 kcal h−1. During training EE in WT was 325.8±73.0 kcal h−1, in WB 374.8±127.1 kcal h−1 and in WR 248.5±69.4 kcal h−1. The average EE of the whole group was: 316.4±89.6 kcal h−1 with a corresponding heart rate of 118.5±23.1 b.p.m. and a lactate concentration of 2.09±0.7 mmol l−1. Statistical analysis showed significantly lower values of EE, heart rate and oxygen uptake for the WR group in comparison to the other groups.Conclusion:The results indicate that the additional leisure time EE of persons participating in WB and WT is sufficient to maintain fitness. This level of EE is comparable to the recommendations of the ACSM for able-bodied persons, and therefore might be sufficient to prevent the development of cardiovascular diseases.

IMPACT OF EXERCISE ON NEUROPLASTICITY-RELATED PROTEINS IN SPINAL CORD INJURED HUMANS

The present study investigated the effects of exercise on the serum concentrations of brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), prolactin (PRL) and cortisol (COR) in 11 chronically spinal cord-injured athletes. In these subjects BDNF concentration at rest was sixfold higher compared with the concentrations reported earlier in able-bodied persons, while IGF-1, PRL and COR were within normal range. Ten minutes of moderate intensity handbiking (54% of the maximal heart rate) during a warm-up period (W) induced an increase (P<0.05) of BDNF of approximately 1.5-fold from basal level at rest, while a decrease to basal level was found after an immediately succeeding handbiking time trial (89% of the maximal heart rate) over the marathon distance of 42 km (M). An increase (P<0.01) of serum IGF-1 was found after W and this levels remained elevated (P<0.01) until the end of M. W had no significant effects on the serum PRL and COR, however, M induced an increase (P<0.01) of both hormones. This is the first study showing elevated BDNF concentrations at rest in spinal cord-injured athletes. Furthermore, short moderate intensity handbiking but not immediately following long lasting high intensity handbiking further increases serum BDNF concentrations. IGF-1 response to exercise differs to BDNF response as this neuroplasticity-related protein remains elevated during the long lasting physical demand with high intensity. The augmented PRL concentration suggests that a possible mechanism by which exercise promotes neuroplasticity might be the activation of neural serotonergic pathways as 5-HT is the main PRL releasing factor. Elevated COR concentrations after M are unlikely to be deleterious to neuroplasticity as COR concentrations remain within the physiological range. The present study suggests that exercise might be beneficial to enhance neuroprotection and neuroplasticity, thereby improving recovery after spinal cord injury.

Energy expenditure in wheelchair racing and handbiking - a basis for prevention of cardiovascular diseases in those with disabilities:

Objective Handbiking and wheelchair racing have gained increased popularity in Germany. This is important because of the inability of wheelchair-dependent people to maintain cardiovascular health and fitness through daily activities. The purpose of this study was to evaluate the energy expenditure (EE; kcal/h) of wheelchair-dependent individuals. Methods Ten wheelchair racers (WR) and 17 handbikers (HB) completed a basal metabolism evaluation, an incremental exercise test until exhaustion and an endurance test. Oxygen uptake and carbon dioxide production ( V . O 2 , V . CO 2 ; ml/min), arterialized capillary blood lactate concentration (LA; mmol/l) and heart rate (HR; bpm) were recorded during each test. EE was calculated by indirect calorimetry. Results In the endurance test V . O 2 , V . CO 2 , LA, HR and EE at an intensity corresponding to 2 mmol/l lactate were: HB: 1332 ± 368 ml/min, 1178 ± 303 ml/min, 2.23 ± 0.85 mmol/l, 116.8 ± 19.1 bpm, 389.6 ± 105.4 kcal/h; WR: 1175 ± 285 ml/min, 1145 ± 258 ml/min, 2.65 ± 0.36 mmol/l, 142.5 ± 28.0 bpm, 341.7 ± 84.0 kcal/h. At an intensity corresponding to 4 mmol/l lactate the values were: HB: 1792 ± 408 ml/min, 1666 ± 326 ml/min, 4.27 ± 1.40 mmol/l 146.1 ± 22.8 bpm, 530.1 ± 115.4 kcal/h; WR: 1505 ± 210 ml/min, 1427 ± 188 ml/min, 3.31 ± 1.0 mmol/l, 165.3 ± 22.7 bpm, 445.5 ± 70.8 kcal/h. Conclusion The results show that EE of HB and WR is high enough to maintain fitness and probably to help to prevent cardiovascular diseases even at a moderate intensity.

Brain and exercise : a first approach using electrotomography

PURPOSE The impact of exercise on brain function has gained broad interest. Because hemodynamic and imaging studies are difficult to perform during and after exercise, electroencephalography (EEG) is often the method of choice. Within this study, we aimed 1) to extend prior work examining changes in scalp-recorded brain electrical activity associated with exercise and 2) to use a distributed source localization algorithm (standardized low-resolution brain electromagnetic tomography [sLORETA]) to model the probable neural sources of changes in EEG activity after exercise. METHODS Electrocortical activity of 22 recreational runners (21-45 yr) was recorded before and after exhaustive treadmill ergometry. Data were analyzed using sLORETA. RESULTS There was an increase in alpha-1 activity (7.5-10 Hz) immediately after exercise, which was localized to the left frontal gyrus (Brodmann area 8). This finding is consistent with alterations in emotional processing. Fifteen minutes after exercise, a decrease in alpha-2 (10-12.5 Hz), beta-1 (12.5-18 Hz), and gamma activities (35-48 Hz) was observed in Brodmann areas 18 and 20-22, which are well known to be involved in language processing. CONCLUSION This study demonstrates that sLORETA is a robust method that allows brain activity maps to be generated from standardized EEG recordings following exercise.

The effect of parabolic flight on perceived physical, motivational and psychological state in men and women: Correlation with neuroendocrine stress parameters and electrocortical activity

Previous findings of decreased mental and perceptual motor performance during parabolic flights have been attributed mainly to the primary effects of weightlessness rather than the accompanying effects of stress and altered mood. Although recent studies have alluded to the possible negative effects of stress on performance, there has been no attempt to investigate this during parabolic flights. Over a period of 3 years, 27 human participants (male n = 18, mean age ± SD 34.67 ± 7.59 years; female n = 9, 36.22 ± 9.92 years) were recruited with the aim to evaluate if, and to what extent, parabolic flights are accompanied by changes in mood. Furthermore, the relationships between mood and physiological markers of stress and arousal, namely circulating stress hormones (ACTH, cortisol, epinephrine, norepinephrine, prolactin and brain activity (EEG)) were investigated. A strong and significant correlation was found between circulating stress hormone concentrations and perceived physical state, motivational state (MOT) and psychological strain (PSYCHO), whereas no interaction between mood and EEG or EEG and stress hormone concentrations was observed. Therefore, two different stress responses appear to be present during parabolic flight. The first seems to be characterised by general cortical arousal, whereas the second seems to evolve from the adrenomedullary system. It is likely that both these mechanisms have different effects on mental and perceptual motor performance, which require further investigation and should to be taken into account when interpreting previous weightlessness research.

Handbiking: Physiological Responses to Synchronous and Asynchronous Crank Montage

Handbiking as a wheelchair sport has gained increased popularity in Germany. It is an attractive sport and seems to be important for the prevention of cardiovascular diseases. For a handbike (HB), the position of the cranks can be synchronous (CS) or asynchronous (CA). The purpose of this study was to examine both forms of riding in persons with a spinal cord injury who are used to a HB. Thirty-five athletes with a spinal cord injury (32 paraplegically and 3 quadriplegically handicapped persons) from Germany agreed to participate in the present investigation. All subjects performed 2 multistage incremental exercise tests until exhaustion sitting in their own HB that was fixed to an ergometer. The tests were randomized for the crank montage. Statistical analysis revealed significantly higher maximal workload in CS compared to CA but no differences in maximal HR and LA. At defined workload intensities, we found lower VO2 values for CS at 30, 60, and 90 W and lower HR for CS at 90 W. LA values were significantly lower for CA at 30 W and higher at 90 W, with no difference at 60 W. We therefore conclude that CS has a higher efficiency for athletes who are used to a HB.

Performance profile and health assessment of elite quad rugby players

Objective: Since 1992, the sport of quad rugby has gained increasing popularity in Germany. This has led to the desire to record reference parameters of func-tional efficiency. Investigation: Thirteen male, quadriplegically handicapped quad rugby players from the German league took part in the investigation. The maximum functional efficiency (W) and speed (m/s) with associated heart rate and lactate values were 45.4 ± 6.9 W, 124.0 ± 19.0 bpm, 4.07 ± 1.09 mmol/L using the arm crank. On the frictionless roller, the values were 2.17 ± 0.48m/s, 133.0 ± 19.1 bpm, 3.91 ± 1.42 mmol/L. In the field test, the values were 3.01 ± 0.64m/s, 142.1 ± 27.5 bpm, 5.63 ± 3.05 mmol/L. Comparison of the heart rate and lactate parameters at the arm crank and on the frictionless roller under maximum load revealed significantly higher heart rate (p = .037) with no sig-nificant differences in lactate (p = .660; n = 13). Conclusion: Health assess-ments in quad rugby are possible using arm crank and frictionless roller ergometry. The essential requirement for being encouraged to make use of performance assessments is that they are carried out as specific as possible with respect to the type of sport involved.

Centrifugal acceleration to 3Gz is related to increased release of stress hormones and decreased mood in men and women.

It has been suggested that the central and peripheral neural processes (CPNP) are affected by gravitational changes. Based on the previous experiments during parabolic flights, central and peripheral changes may not only be due to the changed gravitational forces but also due to neuroendocrine reactions related to the psycho-physiological consequences of gravitational changes. The present study focuses on the interaction of neuroendocrine changes and the physical and mental states after acceleration to three-time terrestrial gravity (3Gz). Eleven participants (29.4 ± 5.1 [SD] years (male (n = 8): 30 ± 5.1 years; female (n = 3): 27.7 ± 2.1 years) underwent a 15 min acceleration to 3Gz in a human centrifuge. Before and after the acceleration to 3Gz circulating stress hormone concentrations (cortisol, adrenocorticotropic hormone (ACTH), prolactin, epinephrine, norepinephrine) and perceived physical and mental states were recorded. A second control group of 11 participants underwent the same testing procedure in a laboratory session. Serum cortisol concentration during exposure to the centrifugal acceleration increased by 70%, plasma concentration of ACTH increased threefold, prolactin twofold, epinephrine by 70% and norepinephrine by 45%, whereas the perceived physical well-being decreased. These findings demonstrate that psycho-physiological changes have to be regarded as a relevant factor for the changes in CPNP during phases of hypergravity exposure.

The exercise profile of an ultra-long handcycling race: the Styrkeprøven experience.

Background:The high mechanical efficiency of the geared handcycle makes it suitable for elite athletes to train and even compete in races with able-bodied (recreational) cyclists. However, the actual exercise profile for endurance events has not been quantified.Objective:To guide future training regimes in a safe and effective process, the aim of this research was to quantify the workload, speed, cadence and heart rate parameters during 6000 km of training and within a 540 km ultra-long races.Methods:One spinal cord injured participant (lesion level Th4, ASIA B) handcycle (modified Shark S Sopur—Sunrisemedical, Malsch, Germany) was equipped with Schoberer Bike Measurement System (SRM) crank. For the laboratory test, a Cyclus II Ergometer was used. The energy intake and quality was determined during the time of race (540 km).Results:Workload at a defined metabolic situation was augmented through training by 63.8% from 90.0 to 147.6 W. The athlete finished the 540 km race with an average speed of 21.6 km h–1 and a total race time of 38:52 h.Conclusions:Ultra-long-term races in a handcycle can be suited by well-trained persons with a spinal cord injury. The quality of the training preparation time (for example, intensity and volume) is of immense importance to reach an adequate physiological capacity and to avoid serious injuries or medical problems.