Nurse facilitated 5000 m running at Parkrun improves vulnerable adolescent health in a high deprivation area: A matched pair randomized control trial.

OBJECTIVE: To examine the effect of weekly nurse facilitated 5000 m running at Parkrun on markers of health in vulnerable adolescents from a high deprivation area. DESIGN: A matched pair randomized control trial. SAMPLE: Twenty-five adolescents aged 13-18, 90% identifying as Maori/Pasifika ethnicity. INTERVENTION: The intervention (INT) group participated in 6-10 Parkruns within 10 weeks, and a control group (CON) participated in one Parkrun only. A nurse facilitated the intervention offering support and encouragement at each Parkrun. MEASUREMENTS: Pre- and post-intervention testing sessions for cardiorespiratory fitness (CRF), glycated hemoglobin, body mass index (BMI), skeletal muscle mass (SMM), body fat, and hand grip strength (STR) were conducted. RESULTS: Parkrun improved CRF (F = 5.308, p = 0.035) and 5000 m time (t = 2.850, p = 0.019) by 5.5 ± 4.9 min (11.2%). Parkrun conferred a large beneficial effect on CRF (η2 = 0.249) a moderate beneficial effect on glycated hemoglobin levels (η2 = 0.119), and small beneficial effects upon SMM (η2 = 0.037) and body fat (η2 = 0.017). CONCLUSION: A weekly dose of nurse facilitated Parkrun can be recommended as a simple, accessible intervention that confers multiple beneficial effects on markers for health in adolescents from a high deprivation area.

Is Stryd critical power a meaningful parameter for runners?

Stryd is a foot pod that reliably estimates running power. Our objectives were to examine the efficacy of the website-generated Stryd critical power (CPSTRYD) as a meaningful parameter for runners. 20 runners performed their regular training while wearing Stryd for a minimum of 6 weeks to generate CPSTRYD. Runners completed laboratory graded exercise testing, and outdoor 1500 m and 5000 m time trails. CPSTRYD was most similar to the second ventilatory threshold (VT2) or the onset of blood lactate accumulation (OBLA) and is highly predictive of running performance. Stryd ground contact time (GCT) was a predictor of performance when comparing runners at the same submaximal treadmill speed. CPSTRYD generated from outdoor running is equivalent to that calculated using an established CP model. However, variance between different methods of CP estimation must be a consideration for runners and coaches. Stryd offers meaningful data for runners including a realistic estimate of CP.

Can physical activity be simplified for health benefit?

AIM: Physical activity (PA) offers protective benefits against at least 25 chronic conditions including psychological stress. The health benefits of PA may be largely attributed to improvements in cardiorespiratory fitness (CRF). However, current guidelines based on PA duration and intensity are controversial, and both are prone to measurement error. We designed a New Zealand specific physical activity frequency and type (PAFT) question, our aims were to examine if PAFT could predict CRF and psychological stress status. METHODS: In experiment one, 20 subjects who regularly perfumed vigorous type PA completed PAFT prior to World Health Organization (WHO) recommended cardiorespiratory fitness (CRF) (VO2Peak) estimation in a controlled exercise laboratory. In experiment two, 81 subjects completed PAFT and a reliable validated measure of stress (the ten-item Perceived Stress Scale (PSS-10)). RESULTS: Vigorous type PA frequency had a strong association (R2=0.71, p<0.01) with VO2Peak and was also the most significant (p<0.01) predictor of low stress. CONCLUSIONS: A simple quick PA type and frequency question predicts CRF and stress status. PA duration and intensity are not required to estimate the health benefits of PA. Two vigorous type PA activities per week can be recommended as a minimum PA dose to decrease risk of stress in similar populations.

Caffeine metabolites are associated with different forms of caffeine supplementation and with perceived exertion during endurance exercise.

This investigation compared the urine caffeine metabolites produced from different forms of caffeine supplementation given to runners 15 minutes before a series of 5-km running trials. Fourteen amateur competitive runners completed a series of self-paced outdoor time trials following ingestion of placebo or one of three alternate forms of caffeine supplement. Trials were randomized in a crossover design with equivalent doses of caffeine (4.0 mg.kg-1) administered 15 minutes before each trial via chewing gum, a novel dissolvable mouth strip or tablet. Runners produced a urine sample following each caffeinated trial that was tested for caffeine and its metabolites by high-performance liquid chromatography. The tablet form of caffeine produced a lower (p = 0.04) urinary ratio of the metabolite paraxanthine to caffeine compared with either gum or strip. Independently of caffeine delivery mode, subjects who metabolized a higher proportion of caffeine to paraxanthine recorded a lower (p = 0.01) perceived exertion. We demonstrate that oral swallowed caffeine administered 15 minutes before 5-km running is less metabolized compared with caffeinated products designed to be chewed or dissolved in the mouth. We suggest the metabolism of caffeine to paraxanthine has an inverse relationship with perceived exertion independently of caffeine delivery mode.

The Effects of Different Forms of Caffeine Supplement on 5-km Running Performance.

PURPOSE: Caffeine is frequently used by athletes as an ergogenic aid. Various alternate forms of caffeine administration are available, which may produce different effects. This investigation compares the effects of different forms of caffeine supplementation on 5-km running performance, and the relationship between athlete ability and degree of enhancement attained. METHODS: Fourteen amateur runners completed a series of self-paced outdoor time trials following unknown ingestion of a placebo (P) or one of 3 alternate forms of caffeine supplement. Trials were randomized in a crossover design with caffeine (approximately 3-4.5 mg·kg-1) administered 15 minutes before each trial via chewing gum (CG), dissolvable mouth strips (CS), or tablet (CT). RESULTS: Compared with P, all caffeine supplements led to worthwhile enhancements in running performance with a mean (±95% confidence limit) overall effect across all supplements of 1.4% ± 0.9%. Individual caffeine treatment effects (CG = 0.9% ± 1.4%, CS = 1.2% ± 1.0%, and CT = 2.0% ± 1.1%) were not significantly different (P > .05) from each other; however, CT trials produced the largest gain and was significantly different (P = .02) compared with P. There was no significant difference in heart rate or rate of perceived exertion across the performance trials. The magnitude of caffeine enhancement was also strongly correlated (r = .87) with no-treatment performance time. CONCLUSIONS: The findings showed that irrespective of delivery form, moderate dose of caffeine supplementation produces worthwhile gains in 5-km running performance compared with a P. Furthermore, the magnitude of caffeine enhancement is highly individualized, but it appears related to athlete performance ability.

Corrected cholesterol, a novel marker for predicting semen post-thaw quality: a pilot study.

Semen cryopreservation is the recommended method for protecting the fertility of men before they undergo iatrogenic treatments. However, post-thaw sperm quality is highly variable between and within individuals. Thus, prediction of post-thaw quality has not been achieved with great certainty. Men (n = 101) attending our andrology clinic each produced a single ejaculate for semen analysis and semen cryopreservation. Post-thaw semen quality was examined for associations with traditional and novel semen and seminal plasma parameters. This current research demonstrates that the cholesterol concentration of human sperm is associated with ejaculate tolerance to cryopreservation. Corrected cholesterol, calculated as the difference between the cholesterol of semen and the cholesterol of cell free seminal plasma, is predictive of post-thaw motility. This may have potential as a method to guide the number of ejaculates stored for individual patients before iatrogenic treatment and/or for the appropriate selection of ART with frozen/thawed semen.

Human sperm cryopreservation in cancer patients: Links with deprivation and mortality.

Evidence is mounting for a relationship between human semen quality and environmental/lifestyle/socioeconomic factors including long term health outcomes such as mortality. The relationship between pre-freeze and post-thaw semen quality in cancer patients and these factors are unknown. Frozen semen from 217 cancer patients was thawed and analysed using a validated CASA method. Post-thaw quality was matched and compared with WHO semen analysis performed prior to storage. The English Indices of Deprivation 2010 were matched with patients and then examined for relationships with pre-freeze and post-thaw semen quality. There is a relationship between semen quality and deprivation in cancer patients. Compared with pre-freeze semen quality, post-thaw semen quality has a stronger relationship with deprivation. Sperm cryopreservation may have potential as a systemic health diagnostic test and is predictive of cancer patient mortality.

Validation of the sperm class analyser CASA system for sperm counting in a busy diagnostic semen analysis laboratory.

Sperm counts have been linked to several fertility outcomes making them an essential parameter of semen analysis. It has become increasingly recognised that Computer-Assisted Semen Analysis (CASA) provides improved precision over manual methods but that systems are seldom validated robustly for use. The objective of this study was to gather the evidence to validate or reject the Sperm Class Analyser (SCA) as a tool for routine sperm counting in a busy laboratory setting. The criteria examined were comparison with the Improved Neubauer and Leja 20-µm chambers, within and between field precision, sperm concentration linearity from a stock diluted in semen and media, accuracy against internal and external quality material, assessment of uneven flow effects and a receiver operating characteristic (ROC) analysis to predict fertility in comparison with the Neubauer method. This work demonstrates that SCA CASA technology is not a standalone 'black box', but rather a tool for well-trained staff that allows rapid, high-number sperm counting providing errors are identified and corrected. The system will produce accurate, linear, precise results, with less analytical variance than manual methods that correlate well against the Improved Neubauer chamber. The system provides superior predictive potential for diagnosing fertility problems.