BackgroundAcid–base balance refers to the equilibrium between acids and bases in the human body. Nutrition may affect acid–base balance and further physical performance. With the help of PRAL (potential renal acid load), a low-protein vegetarian diet (LPVD) was designed to enhance the production of bases in body. The aim of this study was to investigate if LPVD has an effect on blood acid–base status and performance during submaximal and maximal aerobic cycling.MethodsNine healthy, recreationally active men (age 23.5 ± 3.4 yr) participated in the study and were randomly divided into two groups in a cross-over study design. Group 1 followed LPVD for 4 days and group 2 ate normally (ND) before performing a cycle ergometer test. The test included three 10-min stages at 40, 60 and 80% of VO2max. The fourth stage was performed at 100% of VO2max until exhaustion. After 10–16 days, the groups started a second 4-day diet, and at the end performed the similar ergometer test. Venous blood samples were collected at the beginning and at the end of both diet periods and after every stage cycled.ResultsDiet caused no significant difference in venous blood pH, strong ion difference (SID), total concentration of weak acids (Atot), partial pressure of CO2 (pCO2) or HCO3- at rest or during cycling between LPVD and ND. In the LPVD group, at rest SID significantly increased over the diet period (38.6 ± 1.8 vs. 39.8 ± 0.9, p=0.009). Diet had no significant effect on exercise time to exhaustion, but VO2 was significantly higher at 40, 60 and 80% of VO2max after LPVD compared to ND (2.03 ± 0.25 vs. 1.82 ± 0.21 l/min, p=0.035; 2.86 ± 0.36 vs. 2.52 ± 0.33 l/min, p<0.001 and 4.03 ± 0.50 vs. 3.54 ± 0.58 l/min, p<0.001; respectively).ConclusionThere was no difference in venous blood acid–base status between a 4-day LPVD and ND. VO2 was increased during submaximal cycling after LPVD suggesting that the exercise economy was poorer. This had no further effect on maximal aerobic performance. More studies are needed to define how nutrition affects acid–base balance and performance.

The COVID-19 pandemic and social distancing measures targeting the transmission of the virus impacted everyday life in 2020. This study investigated pre- to in-pandemic changes in health behaviors and depressive symptoms during the COVID-19 pandemic and the role of personality traits in these changes in Finland. Data from a larger population-based cohort study of 51–59-year-old Finnish women were used (n = 358). Self-reported questionnaires gathered information about depressive symptoms, eating behavior, physical activity, and alcohol consumption before the pandemic time, at the onset, and at the end of the COVID-19 emergency conditions. Information about personality traits (extraversion and neuroticism) and sociodemographic factors was available from the pre-pandemic baseline. Women reported more depressive symptoms and unhealthier eating habits at the end of the emergency conditions compared to the pre-pandemic time. An increase in depressive symptoms was associated with changing to unhealthier eating habits. Higher extraversion was associated with a perceived decrease in alcohol consumption and with changing to healthier eating habits. Women with higher neuroticism reported changing to either healthier or unhealthier eating habits. In general, some women reported healthier lifestyle changes while other women reported the opposite. Personality traits help to understand these individual differences in adaptation to the pandemic situation.

Purpose: Diet composition influences acid-base status of the body. This may become more relevant as renal functional capacity declines with aging. We examined the effects of low (LD) versus high dietary acid load (HD) on blood acid-base status and exercise performance.Methods: Participants included 22 adolescents (AD), 33 young adults (YA) and 33 elderly (EL), who followed a 7-day LD and HD in a randomized order. At the end of both diet periods the subjects performed a cycle ergometer test (3x10 min at 35%, 55%, 75%, and (except EL) until exhaustion at 100% of VO 2 max). At the beginning of, and after the diet periods, blood samples were collected at rest and after all workloads. VO 2 , RER and HR were monitored during cycling. Results:In YA and EL, bicarbonate (HCO 3 -) and base excess (BE) decreased over the HD period, and HCO 3 -, BE and pH were lower at rest after HD compared to LD. In YA and EL women, HCO 3 -and BE were lower at submaximal workloads after HD compared to LD. In YA women, the maximal workload was 19 % shorter and maximal VO 2 , RER and HR lower after HD compared to LD. Conclusions:Our data uniquely suggests that better renal function is associated with higher availability of bases, which may diminish exercise-induced acidosis and improve maximal aerobic performance. Differences in glomerular filtration rate between the subject groups likely explains the larger effects of dietary acid load in the elderly compared to younger subjects and in women compared to men.

Prolonged effects of dietary acid intake on acid–base status and kidney function have not yet been studied in an intervention study in healthy subjects. Dietary acid load can be estimated by calculating the potential renal acid load (PRAL) of foods. Effects of low-PRAL and moderate-PRAL diets on acid–base status and kidney function were investigated during a 12-week exercise training period. Healthy, 20–50-year-old men (n = 21) and women (n = 25) participated in the study and were randomly divided into low-PRAL and moderate-PRAL groups. Before (PRE), mid-phase (MID) and after the intervention (POST), the subjects participated in measurement sessions, where a 12-h urine sample and fasting blood samples were collected, and a submaximal cycle ergometer test was performed. Net acid excretion was significantly lower after 12 weeks of the low-PRAL diet as compared to the moderate-PRAL diet, both in men and women. In low-PRAL females, capillary pH and bicarbonate were significantly higher at 75% of VO2max at POST as compared to PRE. Glomerular filtration rate decreased over the study period in moderate-PRAL men and women. The results of the present study suggest that an acidogenic diet and regularly training together may increase the acidic load of the body and start to impair the kidney function in recreationally active subjects.

Objective To investigate associations of eating behaviour with symptoms of pelvic floor disorders (PFD), i.e., stress urinary incontinence (SUI), urge urinary incontinence (UUI), faecal incontinence (FI), constipation or defecation difficulties (CDD), and feeling of pelvic organ prolapse (POP) among middle-aged women. Design A cross-sectional, observational study. Setting University Research Laboratory. Sample A population sample of 1 098 Finnish women aged 47 to 55 years. Methods Eating behaviour, demographical, gynaecological, and physical activity variables were assessed using self-report questionnaires. Simple and multiple logistic regression models were used to assess the associations of eating behaviour and symptoms of PFD. Models were adjusted with demographical, gynaecological, and physical activity variables. Main outcome measures Prevalence of symptoms of CDD, FI, POP, SUI, UUI. Results After controlling for confounding, middle-aged women with restrictive eating style were more likely to experience the symptoms of CDD (OR 1.73, CI 1.03–2.90, p=0.039). Women with evening-oriented eating pattern were more likely to experience symptoms of UUI (OR 2.01, CI 1.32–3.07, p=0.001) while maintaining healthy eating patterns was associated with lower risk of UUI (OR 0.45, CI 0.24–0.85, p=0.014) in adjusted models. Conclusions This study provides proof-of-concept evidence to the hypothesis that eating behaviour is associated with perceived pelvic floor disorders, particularly CDD and UUI, warranting further studies to investigate causality.