Can intervals enhance the inflammatory response and enjoyment in upper-body exercise?

Purpose To investigate the inflammatory and perceptual responses to three different forms of upper-body exercise. Methods Twelve recreationally active, able-bodied males performed three work-matched arm-crank sessions in a randomised order: 30 min moderate-intensity continuous (CON), 30 min moderate-intensity with changes in cadence (CAD) and 20 min high-intensity interval training (HIIT). Blood samples were taken pre, post and 2-h post-exercise to determine plasma concentrations of interleukin (IL)-6 and IL-1ra. Perceptual responses pre, during and following the trials were assessed using the Feeling Scale, Felt Arousal Scale, Ratings of Perceived Exertion (RPE) and the Physical Activity Enjoyment Scale (PACES). Results All trials were evenly effective in inducing an acute inflammatory response, indicated by similar increases in IL-6 after exercise and in IL-1ra at 2-h post exercise for all trials. More negative affect and higher RPE were reported during HIIT compared to CON and CAD, whereas PACES scores reported after exercise were higher for HIIT and CAD compared to CON. Conclusions When matched for external work, there was no difference in the inflammatory response to HIIT compared to moderate-intensity upper-body exercise. Although HIIT was (perceived as) more strenuous and affective responses were more negative during this mode, the higher ratings of enjoyment for both HIIT and CAD reported after exercise suggest that the inclusion of variation enhances enjoyment in upper-body exercise. As the fashion in which upper-body exercise is performed does not seem to influence the inflammatory response, it might be advised to prescribe varied exercise to enhance its enjoyment

Exercise intensity and its impact on relationships between salivary immunoglobulin A, saliva flow rate and plasma cortisol concentration

Introduction Salivary secretory immunoglobulin A (sIgA), saliva flow rate and plasma cortisol concentrations have been shown to be influenced by exercise, particularly the intensity exercise is performed at, and circadian variation. The autonomic nervous system partly regulates salivary secretion, but it is not yet known whether cortisol also explains some variation in salivary parameters. Methods Twelve moderately trained male individuals (V̇ O2peak legs: 46.2±6.8 mL·kg−1·min−1) performed three 45-min constant load exercise trials in the morning: arm cranking exercise at 60%V̇ O2peak arms; moderate cycling at 60%V̇ O2peak legs; and easy cycling at 60%V̇ O2peak arms. Timed saliva samples and blood samples for plasma cortisol concentration determination were obtained before, post, 2 h post, and 4 h post-exercise. Saliva was collected in an additional resting trial at the same time points. Results At each time point for each exercise trial, negative correlations between cortisol and saliva flow rate (explaining 25±17% of the variance, R2=0.002–0.46) and positive correlations between cortisol and sIgA concentration (explaining 8±8% of the variance R2=0.002–0.24) were found. Saliva flow rate increased over time, whereas sIgA concentration and cortisol decreased over time for all trials (P<0.05), there was no effect of time for sIgA secretion rate (P=0.16). Conclusion These results show a relationship between cortisol and saliva flow rate, which directly impacts on the concentration of salivary analytes. This study further confirms circadian variations in salivary parameters which must be acknowledged when standardising salivary data collection

Spinal cord injury: known and possible influences on the immune response to exercise

A spinal cord injury (SCI) can increase the risk of infection by impacting on many aspects of immune function; one particularly well-documented observation is a reduction in lymphocyte numbers. The vast majority of lymphoid cells express adrenergic receptors. Therefore, autonomic function loss and concomitant alterations in resting and post-exercise catecholamine concentrations, particularly so in individuals with a tetraplegia, may impact directly on immune cells and depress immunity. Other factors are further likely to contribute, examples including altered muscular, endocrine and cardiovascular function following SCI. However, some alterations, such as increases in natural killer cell cytotoxicity following exercise in those with a tetraplegia, are unrelated to the catecholamine response. Likewise, mucosal immunity in individuals with a tetraplegia appears to be similarly influenced by exercise as in the able-bodied population. Indeed, rehabilitation therapy and exercise can increase some measures of immunity and autonomic function in those with an SCI. It is therefore possible that compensatory mechanisms offset disability-related detriments. This may be by way of sympathetic reflex activity, receptor hypersensitivity, or parasympathetic and neuroendocrine adjustments. Future work needs to explore these mechanisms further to clarify the implications of an SCI on the immune response to exercise and susceptibility to infection. In this article, we review the impacts of an SCI on immune, and specifically, exercise immune function. The relevant anatomical and physiological foundations of the immune system are first briefly laid out in order to understand the potential impacts of neural and neuroendocrine dysfunction on the immune system. With the limited number of human studies available, we have then aimed specifically to gather all relevant existing literature on exercise immunology in individuals with an SCI in patient, recreationally active and athlete populations. We believe that an understanding of the impacts of exercise can provide a tool to help maintain or improve health in individuals with an SCI

The effect of passive heating on heat shock protein 70 and interleukin-6: a possible treatment tool for metabolic diseases?

Increasing physical activity remains the most widely publicized way of improving health and wellbeing. However, in populations that benefit most from exercise (EX), adherence is often poor and alternatives to EX are important to bring about health improvements. Recent work suggests a role for passive heating (PH) and heat shock proteins (HSP) in improving cardio-metabolic health. The aim of this study was to investigate the expression of HSP70 and interleukin-6 in response to either EX or PH and the subsequent effect on glucose control. Fourteen males volunteered and were categorized lean (BMI 23.5 ± 2.2 kg·m−2) or overweight (29.2 ± 2.7 kg·m−2) and completed 60 minutes of either moderate cycling at a fixed rate of metabolic heat production (EX) or warm water immersion in 40°C water (PH). Extracellular HSP70 increased from baseline in both conditions with no differences between PH (0.98 ± 1.1 ng·mL−1) or EX (0.84 ± 1.0 ng·mL−1, p = 0.814). IL-6 increased following both conditions with a two-fold increase after PH and four-fold after EX. Energy expenditure increased by 61.0 ± 14.4 kcal·h−1 (79%) after PH. Peak glucose concentration after a meal immediately following PH was reduced when compared with EX (6.3 ± 1.4 mmol·L−1 versus 6.8 ± 1.2 mmol·L−1; p < 0.05). There was no difference in 24-hour glucose area under the curve (AUC) between conditions. These data indicate the potential for thermal therapy as an alternative treatment and management strategy for those at risk of developing metabolic disease where adherence, or ability to EX, may be compromised

The effect of temperature and heat shock protein 72 on the ex vivo acute inflammatory response in monocytes

The acute inflammatory response to active or passive activities that increase body temperature may aid to reduce chronic low-grade inflammation. This study investigates the impact of temperature and extracellular heat shock protein 72 (eHsp72) on the acute intracellular Hsp72 (iHsp72) and interleukin-6 (iIL-6) response in monocytes. Whole blood was incubated for 2 h at 37.0 °C, 38.5 °C and 40.0 °C, in the absence or presence of 0.5 μg/ml eHsp72. Flow cytometry was used to assess iHsp72 and iIL-6 expression in total monocytes and the three monocyte subsets. Incubation at 40.0 °C (p < 0.001) but not 38.5 °C (p = 0.085) increased iHsp72 expression when compared with 37.0 °C, while there was no effect of temperature on iIL-6 expression (p = 0.635). Following incubation with eHsp72, the expression of iHsp72 in classical monocytes was reduced at all temperatures (p < 0.001), while there was no effect of eHsp72 on iIL-6 expression (p = 0.071). Large temperature elevations are needed to induce an acute iHsp72 response in monocytes. In addition, contrary to its suggested role as a danger signal for the innate immune system, eHsp72 reduced iHsp72 and iIL-6 expression in monocytes

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometr

Locomotor-respiratory coupling in wheelchair racing athletes: a pilot study

Purpose: In wheelchair racing, respiratory muscles of the rib cage are concomitantly involved in non-ventilatory functions during wheelchair propulsion. However, the relationship between locomotor-respiratory coupling (LRC: the ratio between push and breathing frequency), respiratory parameters and work efficiency is unknown. Therefore, the aim of the present study was to investigate the LRC in wheelchair racers over different race distances. Methods: Eight trained and experienced wheelchair racers completed three time-trials over the distances of 400m, 800m and 5000m on a training roller in randomized order. During the time trials, ventilatory and gas exchange variables as well as push frequency were continu-ously registered to determine possible LRC strategies. Results: Four different coupling ratios were identified, namely 1:1; 2:1, 3:1 as well as a 1:1/2:1 alternating type, respectively. The 2:1 coupling was the most dominant type. The 1:1/2:1 alternating coupling type was found predominantly during the 400m time-trial. Longer race distances tended to result in an in-creased coupling ratio (e.g., from 1:1 towards 2:1), and an increase in coupling ratio towards a more efficient respiration was found over the 5000m distance. A significant correlation (r=0.80, p<0.05) between respiratory frequency and the respiratory equivalent for oxygen was found for the 400m and the 800m time-trials. Conclusions: These findings suggest that a higher coupling ratio indicates enhanced breathing work efficiency with a concomitant deeper and slower respiration during wheelchair racing. Thus, the selection of an appropriate LRC strategy may help to optimize wheelchair racing performance

Hot water immersion acutely increases postprandial glucose concentrations

Background: Chronic hot water immersion (HWI) confers health benefits, including a reduction in fasting blood glucose concentration. Here we investigate acute glycaemic control immediately after HWI. Methods: Ten participants (age: 25 ± 6 years, body mass: 84 ± 14 kg, height 1.85 ± 0.09 m) were immersed in water (39ºC) to the neck (HWI) or sat at room temperature (CON) for 60 min. One hour afterwards they underwent an oral glucose tolerance test (OGTT), with blood collected before and after HWI/CON and during the 2 h OGTT. Results: Glucose incremental area under the curve (iAUC) during the OGTT was higher for HWI (HWI 233 ± 88, CON 156 ± 79 mmol·L-1·2h, P = 0.02). Insulin iAUC did not differ between conditions (HWI 4309 ± 3660, CON 3893 ± 3031 mU·L-1·2h, P=0.32). Core temperature increased to 38.6 ± 0.2°C during HWI, but was similar between trials during the OGTT (HWI 37.0 ± 0.2, CON 36.9 ± 0.4°C, P=0.34). Directly following HWI, plasma average adrenaline and growth hormone concentrations increased 2.7 and 10.7-fold, respectively (P < 0.001). Plasma glucagon like peptide-1, peptide YY and acylated ghrelin concentrations were not different between trials during the OGTT (P > 0.11). Conclusions: HWI increased postprandial glucose concentration to an OGTT, which was accompanied by acute elevations of stress hormones following HWI. The altered glycaemic control appears to be unrelated to changes in gut hormones during the OGTT

A multi-factorial assessment of elite paratriathletes’ response to two weeks of intensified training

Purpose: In able-bodied athletes, several hormonal, immunological and psychological parameters are commonly assessed in response to intensified training due to their potential relationship to acute fatigue and training/non-training stress. This has yet to be studied in Paralympic athletes. Methods: Ten elite paratriathletes were studied for five weeks around a 14-day overseas training camp whereby training load was 137% of pre-camp levels. Athletes provided: six saliva samples (one pre-camp, four during camp, one post-camp) for cortisol, testosterone and secretory immunoglobulin A; weekly psychological questionnaires (POMS and RESTQ-S); daily resting heart rate and subjective wellness measures including sleep quality and quantity. Results: There was no significant change in salivary cortisol, testosterone, cortisol:testosterone ratio or secretory immunoglobulin A during intensified training (p≥0.090). Likewise, there was no meaningful change in resting heart rate or subjective wellness measures (p≥0.079). Subjective sleep quality and quantity increased during intensified training (p≤0.003). There was no significant effect on any POMS subscale other than lower anger (p=0.049) whilst there was greater general recovery and lower sport and general stress from RESTQ-S (p≤0.015). Conclusions: There was little to no change in parameters commonly associated with the fatigued state which may relate to the training camp setting minimising external life stresses and the careful management of training loads from coaches. This is the first evidence of such responses in Paralympic athletes

Salivary alpha amylase not chromogranin A reflects sympathetic activity: exercise responses in elite male wheelchair athletes with or without cervical spinal cord injury

Background: Salivary alpha-amylase (sAA) and chromogranin A (sCgA) have both been suggested as non-invasive markers for sympathetic nervous system (SNS) activity. A complete cervical spinal cord injury leading to tetraplegia is accompanied with sympathetic dysfunction; the aim of this study was to establish the exercise response of these markers in this in vivo model. Methods: Twenty-six elite male wheelchair athletes (C6-C7 tetraplegia: N=8, T6-L1 paraplegia: N=10 and non spinal cord injured controls: N=8) performed treadmill exercise to exhaustion. Saliva and blood samples were taken pre, post, and 30 min post exercise and analysed for sAA, sCgA and plasma adrenaline concentration, respectively. Results: In all three subgroups, sAA and sCgA were elevated post exercise (P<0.05). Whilst sCgA was not different between subgroups, a group x time interaction for sAA explained the reduced post exercise sAA activity in tetraplegia (162±127 vs 313±99 (paraplegia) and 328±131 U∙mL-1 (controls), P=0.005). The post exercise increase in adrenaline was not apparent in tetraplegia (P=0.74). A significant correlation was found between adrenaline and sAA (r=0.60, P=0.01), but not between adrenaline and sCgA (r=0.06, P=0.79). Conclusions: The blunted post-exercise rise in sAA and adrenaline in tetraplegia implies that both reflect SNS activity to some degree. It is questionable whether sCgA should be used as a marker for SNS activity, both due to the exercise response which is not different between the subgroups and its non-significant relationship with adrenaline