The effect of short-term intermittent hypoxic exposure on heart rate variability in a sedentary population

While the effects of instantaneous, single-bout exposure to hypoxia have been well researched, little is known about the autonomic response during, or as an adaptation to, repeated intermittent hypoxic exposure (IHE) in a sedentary population. Resting heart rate variability (HRV) and exercise capacity was assessed in 16 participants (8 receiving IHE, [Hyp] and 8 receiving a placebo treatment [C]) before and after a 4-week IHE intervention. Heart rate variability was also measured during an IHE session in the last week of the intervention. Post-intervention, the root mean squared successive difference (rMSSD) increased substantially in Hyp (71.6 ± 52.5%, mean change ± 90% confidence limits) compared to C suggesting an increase in vagal outflow. However, aside from a likely decrease in submaximal exercise heart rate in the Hyp group (–5.0 ± 6.4%) there was little evidence of improved exercise capacity. During the week 4 IHE measurement, HRV decreased during the hypoxic exposure (reduced R-R interval: –7.5 ± 3.2%; and rMSSD: –24.7 ± 17.3%) suggesting a decrease in the relative contribution of vagal activity. In summary, while 4 weeks of IHE is unlikely to improve maximal exercise capacity, it may be a useful means of increasing HRV in people unable to exercise

Associations between physical activity and stress levels in medical doctors working in New Zealand and Australia during initial COVID-19 restrictions

In 2020, the world was gripped by the COVID-19 pandemic which put an unprecedented strain on health care workers. The aim of this study was to assess the effects of the Australian and New Zealand lockdowns on physical activity, depression, and anxiety in medical doctors. We hypothesized that during stressful times such as the COVID-19 pandemic lockdown, physical activity would have a positive effect on the mental health of medical doctors. Convenience sampling (using mass emailing via professional networks including medical associations) and snowball sampling were used during the early period of COVID-19 government mandated restrictions (25 March to 27 April 2020) in New Zealand and Australia. All registered medical doctors working in New Zealand and Australia were eligible to participate in the survey. The short survey collected information demographics, levels of physical activity and mental health using the International Physical Activity Questionnaire: Short Form and the Depression, Anxiety and Stress Scale-42. Of 469 participants who completed the survey, over 81% met the recommended physical activity levels (150 minutes of at least moderate-intensity physical activity/week). Physically inactive New Zealand and Australian medical doctors reported significantly higher depression (p = 0.006), anxiety (p = 0.008) and stress (p = 0.002) scores compared to their active counterparts. This study demonstrated that less physical activity was associated with higher anxiety and depression in medical doctors. A key recommendation from this study is to incorporate greater access to physical activity in healthcare settings for medical doctors

Does intermittent hypoxic exposure enhance the cardioprotective effect of exercise in an inactive population?

The aim of this study was to determine whether exercise supplemented with passive intermittent hypoxic exposure (IHE) improved overall cardiovascular disease risk and individual risk factors. Participants were randomized to exercise-only (Ex, n = 18, 5 males, 13 females; age: 56.4 ± 6.5 years; weight: 81.2 ± 15.9; height: 167.3 ± 8.42) or exercise + IHE (IHE + Ex, n = 16; 6 males, 10 females; age: 56.7 ± 6.4 years; weight: 78.6 ± 12.4 kg; height: 168.0 ± 8.8 cm). Both groups received the same strength and aerobic exercise training (1 h, 3 days/wk, 10 weeks). IHE + Ex also received IHE (5 min hypoxia: 5 min ambient air ×6) for 2–3 days/wk. Measurements were collected before (Baseline), after (Post), and 4- and 8-week following the intervention. There were small, beneficial reductions in overall 5- year cardiovascular risk in both groups. At Post, for IHE + Ex compared to IHE there were unclear to likely improvements in high density lipoprotein (8.0% ± 8.0%), systolic blood pressure (−3.4% ± 3.4%) and VO₂peak (3.1% ± 7.7%). These improvements persisted at 8-week. There was an unclear improvement in arterial wave reflection (augmentation index) at Post (−6.1% ± 18.4%, unclear), but became very likely harmful at 8-week (8-week: 24.8% ± 19.7%). The conflicting findings indicate that in inactive adults, the addition of IHE to exercise may be beneficial to systemic markers of cardiovascular health but may also increase myocardial load due to increased arterial wave reflection

Difficulties in establishing a timely diagnosis of pulmonary artery sarcoma misdiagnosed as chronic thrombo-embolic pulmonary disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>Pulmonary artery sarcomas are rare neoplasms that are often confused with chronic thrombo-embolic disease, as both can have similar clinical and imaging presentation.</p> <p>Case presentation</p> <p>In this report, we present a case of a 50-year-old man initially diagnosed with chronic thrombo-embolic pulmonary disease, but who was later found to have pulmonary artery sarcoma with poor survival prognosis. We review the clinical and imaging characteristics of the two diseases and discuss the difficulties in establishing a timely diagnosis.</p> <p>Conclusion</p> <p>Similar clinical features and imaging presentation of pulmonary artery sarcoma and chronic thrombo-embolic pulmonary disease make definitive diagnosis difficult. This case report also illustrates and emphasizes that in any case with no predisposition factors for embolism, no evidence of deep venous thrombosis and pulmonary emboli, and inadequate relief of symptoms with anticoagulation, an alternative diagnosis of pulmonary artery sarcoma should be considered. If pulmonary artery sarcoma is diagnosed late in the course of the disease, there is usually a poor survival outcome.</p

Long-term effectiveness of the New Zealand Green Prescription primary health care exercise initiative

The rising incidence of non-communicable diseases in western countries is being driven by poor lifestyle choices, including increasingly inadequate physical activity. The aim of this study was to quantify the effectiveness of a physical activity primary care intervention named the ‘Green Prescription’ on changes in physical activity levels 2–3 year's following original prescription. Study design A retrospective study design using a telephone interview. Methods Physical activity and health information was gathered from participants in June–September 2015, who were originally prescribed a primary care physical activity intervention 2–3 years ago. Respondents were classified as either having completed the programme (adherence group, n = 91) or having not completed the programme (non-adherence group, n = 56). Results Participants who had completed the programme within the past 2–3 years reported an additional 64 min (95% CI = 16–110) of total physical activity per week compared to those who had dropped out. Forty-two percent of participants in the adherence group reported increased physical activity levels after receiving the Green Prescription compared to 29% in the non-adherence group. The adherence group were less likely to be sedentary (odds ratio 0.7, 95% CI = 0.5–0.9) and more likely to meet the current physical activity guidelines of at least 150 min of physical activity per week (OR = 1.1, 95% CI = 1.0–1.3). Conclusions The findings indicate a long-term benefit is likely to participants who completed Green Prescription

Monitoring training loads and perceived stress in young elite university athletes

With increased professionalism in sport there has been a greater interest in the scientific approach to training and recovery of athletes. Applying appropriate training loads along with adequate recovery, is essential in gaining maximal adaptation in athletes, while minimizing harm such as overreaching, overtraining, injury and illness. Although appropriate physical stress is essential, stress for many athletes may come from areas other than training. Stress from may arise from social or environmental pressure, and for many athletes who combine elite athletic training with university study, academic workloads create significant stress which adds to the constant pressure to perform athletically. This research aimed to determine if subjective stressors were associated with counterproductive training adaptations in university athletes. Moreover, it aimed to elucidate if, and when, such stressors are most harmful (i.e., certain times of the academic year or sports training season). We monitored subjective (mood state, energy levels, academic stress, sleep quality/quantity, muscle soreness, training load) and objective (injury and illness) markers in 182 young (18–22 years) elite athletes over a 4-year period using a commercially available software package. Athletes combined full-time university study with elite sport and training obligations. Results suggest athletes were relatively un-stressed with high levels of energy at the beginning of each university semester, however, energy levels deteriorated along with sleep parameters toward the examination periods of the year. A logistical regression indicated decreased levels of perceived mood (0.89, 0.85–0.94, Odds Ratio and 95% confidence limits), sleep duration (0.94, 0.91–0.97) and increased academic stress (0.91, 0.88–0.94) and energy levels (1.07, 1.01–1.14) were able to predict injury in these athletes. Examination periods coincided with the highest stress levels and increased likelihood of illness. Additionally, a sudden and high increase in training workload during the preseason was associated with an elevated incidence of injury and illness (r = 0.63). In conclusion, young elite athletes undertaking full-time university study alongside their training and competition loads were vulnerable to increased levels of stress at certain periods of the year (pre-season and examination time). Monitoring and understanding these stressors may assist coaches and support staff in managing overall stress in these athletes