Skeletal site-specific effects of jump training on bone mineral density in adults: a systematic review and meta-analysis.

Preserving or preventing declines in bone mineral density (BMD) is imperative. As jumping is a high-impact bone-loading action, this meta-analysis evaluated the efficacy of jump training to improve BMD and bone turnover relative to non-jumping controls in men and women > 18 years, following Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines. PubMed and COCHRANE Library databases were searched until February 2022.

Evaluating the impact of the COVID-19 pandemic on performance during the 2022 56 km Two Oceans ultra-marathon.

Background: The 56km Two Oceans ultra-marathon (TOM), in Cape Town, South Africa, was cancelled in 2020 and 2021 because of the COVID-19 pandemic. Since most other road running events were also cancelled during this period, we hypothesized that most athletes who entered TOM 2022 would be inadequately trained, which would negatively affect performance. However, many world records were broken post-lockdown, and therefore the performance, specifically of the elite athletes, during TOM might actually improve.

The Impact of Sodium Alginate Hydrogel on Exogenous Glucose Oxidation Rate and Gastrointestinal Comfort in Well-Trained Runners.

Purpose: The purpose of this study is to quantify the effect of adding sodium alginate and pectin to a carbohydrate (CHO) beverage on exogenous glucose (ExGluc) oxidation rate compared with an isocaloric CHO beverage.

Methods: Following familiarization, eight well-trained endurance athletes performed four bouts of prolonged running (105 min; 71 ± 4% of VOmax) while ingesting 175 mL of one of the experimental beverages every 15 min. In randomized order, participants consumed either 70 gh of maltodextrin and fructose (10% CHO; NORM), 70 gh of maltodextrin, fructose, sodium alginate, and pectin (10% CHO; ENCAP), 180 gh of maltodextrin, fructose, sodium alginate, and pectin (26% CHO; HiENCAP), or water (WAT).

Carbohydrate-Restricted Exercise With Protein Increases Self-Selected Training Intensity in Female Cyclists but Not Male Runners and Cyclists.

Oosthuyse, T, Florence, GE, Correia, A, Smyth, C, and Bosch, AN. Carbohydrate-restricted exercise with protein increases self-selected training intensity in female cyclists but not male runners and cyclists. J Strength Cond Res 35(6): 1547-1558, 2021-Carbohydrate-restricted training challenges preservation of euglycemia and exercise intensity that precludes ergogenic gains, necessitating countering strategies.

Physiological and Metabolic Responses to Exercise on Treadmill, Elliptical Trainer, and Stepper: Practical Implications for Training.

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities.

Mountain Bike Racing Stimulates Osteogenic Bone Signaling and Ingesting Carbohydrate-Protein Compared With Carbohydrate-Only Prevents Acute Recovery Bone Resorption Dominance.

Oosthuyse, T, Bosch, AN, Kariem, N, and Millen, AME. Mountain bike racing stimulates osteogenic bone signaling and ingesting carbohydrate-protein compared with carbohydrate-only prevents acute recovery bone resorption dominance. J Strength Cond Res 35(2): 292-299, 2021-Mountain biking, unlike road cycling, includes vibrational accelerations but whether it stimulates osteogenic signaling remains unknown.

Effect of ingesting carbohydrate only or carbohydrate plus casein protein hydrolysate during a multiday cycling race on left ventricular function, plasma volume expansion and cardiac biomarkers.

Purpose: Multiday racing causes mild left ventricular (LV) dysfunction from day 1 that persists on successive days. We evaluated ingesting casein protein hydrolysate-carbohydrate (PRO) compared with carbohydrate-only (CHO) during a 3-day mountain bike race.

Methods: Eighteen male cyclists were randomly assigned to ingest 6.

Assessment of Differences in the Anthropometric, Physiological and Training Characteristics of Finishers and Non-finishers in a Tropical 161-km Ultra-marathon.

This study aimed to compare and determine the differences in the physiological, anthropometric and training characteristics of the finishers (FIN) and non-finishers (N-FIN) in a 161-km race. Two groups of runners (FIN; N=12 and N-FIN; N=14) completed a series of anthropometric and physiological measurements over two separate sessions at least three weeks prior to the race. Training sessions starting from six weeks prior to the race were recorded.

The Effect of Gender and Menstrual Phase on Serum Creatine Kinase Activity and Muscle Soreness Following Downhill Running.

Serum creatine kinase (CK) activity reflects muscle membrane disruption. Oestrogen has antioxidant and membrane stabilising properties, yet no study has compared the CK and muscle soreness (DOMS) response to unaccustomed exercise between genders when all menstrual phases are represented in women. Fifteen eumenorrhoeic women (early follicular, EF ( = 5); late follicular, LF ( = 5); mid-luteal, ML ( = 5) phase) and six men performed 20 min of downhill running (-10% gradient) at 9 km/h.

Similarities and Differences in Pacing Patterns in a 161-km and 101-km Ultra-Distance Road Race.

Tan, PLS, Tan, FHY, and Bosch, AN. Similarities and differences in pacing patterns in a 161-km and 101-km ultra-distance road race. J Strength Cond Res 30(8): 2145-2155, 2016-The purpose of this study was to establish and compare the pacing patterns of fast and slow finishers in a tropical ultra-marathon.

Oestrogen's regulation of fat metabolism during exercise and gender specific effects.

Early animal, menstrual phase and gender comparative studies inconsistently support an oestrogen-induced increase in fat oxidation during exercise. Recent advances from studies of cellular signalling and gene expression provide evidence for inter-tissue and intramuscular mechanisms that demonstrate oestrogen's promotion of skeletal muscle fat oxidative capacity. Oestrogen or oestrogen-analogues act mainly through oestrogen receptor-alpha in skeletal muscle to stimulate the genomic expression of certain other nuclear hormone receptors and downstream targets to promote long chain fatty acid (LCFA) uptake, mitochondrial shuttling and β oxidation.

The effect of a second runner on pacing strategy and RPE during a running time trial.

Purpose: The aim of this study was to examine performance, pacing strategy and perception of effort during a 5 km time trial while running with or without the presence of another athlete.

Methods: Eleven nonelite male athletes participated in five 5 km time trials: two self-paced, maximal effort trials performed at the start and end of the study, and three trials performed in the presence of a second runner. In the three trials, the second runner ran either in front of the subject, behind the subject, or next to the subject.

The effect of the menstrual cycle on exercise metabolism: implications for exercise performance in eumenorrhoeic women.

The female hormones, oestrogen and progesterone, fluctuate predictably across the menstrual cycle in naturally cycling eumenorrhoeic women. Other than reproductive function, these hormones influence many other physiological systems, and their action during exercise may have implications for exercise performance. Although a number of studies have found exercise performance - and in particular, endurance performance - to vary between menstrual phases, there is an equal number of such studies reporting no differences.

Metabolic consequences of exercise-induced muscle damage.

Exercise-induced muscle damage (EIMD) is commonly experienced following either a bout of unaccustomed physical activity or following physical activity of greater than normal duration or intensity. The mechanistic factor responsible for the initiation of EIMD is not known; however, it is hypothesised to be either mechanical or metabolic in nature. The mechanical stress hypothesis states that EIMD is the result of physical stress upon the muscle fibre.

Variability in exercise capacity and metabolic response during endurance exercise after a low carbohydrate diet.

The impact of altered blood glucose concentrations on exercise metabolism and performance after a low carbohydrate (CHO) diet was investigated. In random order, 1 wk apart, 9 trained men underwent euglycemic (CI) or placebo (PI) clamps, while performing up to 150 min of cycling at 70% VO2(max), after 48 h on a low CHO diet. The range in improvement in endurance capacity with glucose infusion was large (28 +/- 26%, P < 0.

The interaction of aging and 10 years of racing on ultraendurance running performance.

The aim of this study was to examine the interaction between aging and 10 years of racing in endurance runners. Race-time data from 194 runners who had completed 10 consecutive 56-km ultramarathons were obtained. The runners were either 20.

Cycling time trial performance during different phases of the menstrual cycle.

Submaximal exercise performance has not previously been assessed in the late follicular phase of the menstrual cycle, which is associated with a pre-ovulatory surge in oestrogen. Therefore, we compared cycling time trial performance during the early follicular (EF), late follicular (LF) and mid-luteal (ML) phase of the menstrual cycle in trained and untrained eumenorrhoeic women who cycled 30 and 15 km, respectively, in a non-fasted state. The women completed the three cycling time trials on a conventional racing bicycle mounted on an air-braked ergometer.

Effect of menstrual phase on the acetate correction factor used in metabolic tracer studies.

The acetate correction factor is used to account for retention of carbon label in exchange reactions of the tricarboxylic acid cycle in studies estimating free fatty acid oxidation with carbon-labeled tracers. Previous evidence indicates that substrate utilisation and metabolic rate vary across the menstrual cycle, which may alter the correction factor. We therefore derived the acetate correction factor for each of three menstrual phases (early follicular [EF], late follicular [LF], and midluteal [ML] phase) from the fractional recovery of 13CO2 from a constant infusion of sodium-[1-13C] acetate during 90 min of submaximal exercise (60% VO2-max) in sedentary eumenorrhoeic women.