Andrew N Bosch

University of Cape Town | UCT · Division of Exercise Science & Sports Medicine, Department of Human Biology

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 performa...

Background: Despite the lack of scientific knowledge on the physiological and biomechanical effects of wearing compression garments (CGs), there has been an increase in the use of compression garments (CG) amongst endurance runners. Objectives: To compare marathon race performance, post-race pain, and mid-thigh circumference in marathon runners...

Introduction Scientific and public interest in the potential ergogenic effects of sodium alginate added to a carbohydrate (CHO) beverage has increased in the last ~ 5 years. Despite an extensive use of this technology by elite athletes and recent research into the potential effects, there has been no meta-analysis to objectively elucidate the effec...

Background: Anecdotal evidence suggests that athletes struggle to return to exercise post COVID-19 infection. However, studies evaluating the effect of COVID-19 on athletes' exercise activity are limited. Objectives: The objectives of this study were: (i) to describe the perceptions of recreational runners and cyclists recovering from COVID-19 o...

Background: Recombinant human erythropoietin (rHuEpo) abuse by athletes threatens the integrity of sport. Due to the overlap in physiological response to rHuEpo and altitude exposure, it remains difficult to differentiate changes in hematological variables caused by rHuEpo or altitude, and therefore, other molecular methods to enhance anti-doping...

PurposeThe 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...

Swimrun was established in Sweden in 2006. In competition athletes alternate between running and swimming multiple times. It has grown from only being hosted in Sweden to now being a global sport. The swimrun race exposes athletes to environments that require a unique set of skills. For example, participants have to negotiate ocean currents and wav...

Τα παγκόσμια ρεκόρ τόσο στους άνδρες όσο και στις γυναίκες από το αγώνισμα των 5 km μέχρι και τον μαραθώνιο δρόμο έχουν καταρριφθεί μετά την εισαγωγή στην παραγωγή του παπουτσιού με την πλάκα του άνθρακα (CFP) το 2016. Αυτή η σταδιακή βελτίωση της επίδοσης, συμπίπτει με τις πρόσφατες εξελίξεις στην τεχνολογία παπουτσιών που αυξάνουν τις ελαστικές ι...

Sport is historically designated by the binary categorization of male and female that conflicts with modern society. Sport’s governing bodies should consider reviewing rules determining the eligibility of athletes in the female category as there may be lasting advantages of previously high testosterone concentrations for transwomen athletes and cur...

A correction to this paper has been published: https://doi.org/10.1007/s40279-021-01467-0

The coronavirus disease (COVID-19) pandemic has had an unprecedent impact on the world of sport and society at large. Many of the challenges with respect to integrity previously facing competitive sport have been accentuated further during the pandemic. Threats to the integrity of sporting competition include traditional doping, issues of technolog...

Rapid advances in wearable technologies and real-time monitoring have resulted in major inroads in the world of recreational and elite sport. One such innovation is the application of real-time monitoring, which comprises a smartwatch application and ecosystem, designed to collect, process and transmit a wide range of physiological, biomechanical,...

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 XX(X): 000-000, 2021-Carbohydrate-restricted training challenges preservation of euglycemia and exercise intensity that pr...

Rationale: The traditional method to measure 13CO2 enrichment in breath involves isotope ratio mass spectrometry (IRMS) and has several limitations such as cost, extensive training and large space requirements. Here we present the validity and reliability data of an isotope ratio infrared spectrometer (IRIS) based method developed to combat these...

Every women’s and men’s world records from 5 km to the marathon has been broken since the introduction of carbon fibre plate (CFP) shoes in 2016. This step-wise increase in performance coincides with recent advancements in shoe technology that increase the elastic properties of the shoe thereby reducing the energy cost of running. The latest CFP sh...

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 submaxim...

Mountain biking, unlike road cycling, includes vibrational accelerations but whether it stimulates osteogenic signaling remains unknown. Furthermore, exercise nutrition influences bone turnover, and the effect of ingesting protein during multiday racing was investigated. We measured plasma bone turnover markers, C-terminal telopeptide of type1-coll...

Eken, MM, Withers, A, Flanagan, K, Burger, J, Bosch, A, and Lamberts, RP. Muscular activation patterns during exercise on the treadmill, stepper, and elliptical trainer. J Strength Cond Res 36(7): 1847-1852, 2022-Because of the low-impact, the stepper and elliptical trainer are popular alternatives to running when runners sustain running-related in...

October 2019 saw Eliud Kipchoge run the marathon distance unofficially in under 2 h, and Brigid Kosgei break Paula Radcliffe’s 16 yr-old marathon record both in carbon fiber plate (CFP) shoes. Current men’s and women’s world records in the half- and full-marathon have all been broken by Nike athletes in CFP shoes, raising concerns that the introduc...

Purpose: To examine the effect of altering osmolality or adding sodium alginate and pectin to a concentrated carbohydrate (CHO) beverage on gastric emptying (GE) rate. Methods: 500 mL boluses of three drinks were instilled double-blind in eight healthy males while seated and GE measured using the double sampling method for 90 min and blood sampl...

PURPOSE: To investigate the effect of CHO encapsulation and osmolarity on the rate of gastric emptying while at rest METHODS: Eight healthy males were recruited to take part in this randomised, double blind, cross-over study. A 500 mL bolus of an experimental drink was instilled while seated, and gastric emptying measured using the double aspirati...

Background: Compression garment utilization is very popular among runners despite a lack of consensus in the literature regarding a beneficial impact. The aim of the study was to investigate the impact of training and competing with compression garments on exercise-induced muscle damage and performance in ultramarathon runners. Hypothesis: Compr...

The benefit of training at altitude to enhance exercise performance remains equivocal although the most widely accepted approach is one where the athletes live and perform lower-intensity running at approximately 2300 m with high-intensity training at approximately 1250 m. The idea is that this method maintains maximal augmentations in total hemogl...

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 6.7% carbohydrate without (C...

Running economy, known as the steady-state oxygen consumption at a given submaximal intensity, has been proposed as one of the key factors differentiating East African runners from other running communities around the world. Kenyan runners have dominated middle-and long-distance running events and this phenomenon has been attributed, in part at lea...

Introduction There is a high incidence of calf injuries in ultradistance runners. Due to the low load, high volume nature of ultradistance running, the stimulation for adaptation in the gastrocnemius from running alone, may not be sufficient to stimulate adaptation. The purpose of this study was to assess the adaption in the architectural and funct...

Objective: International guidelines for pre-participation screening of masters/leisure athletes to identify those that require medical assessment exist, but have not been implemented in mass-community based sports events. We determined the prevalence of runners who, according to these guidelines, would require a medical assessment before participat...

Objective.—This study compared pacing patterns and thermoregulation of finishers (FIN) and non-finishers (N-FIN) running a hot, humid 161-km ultra-marathon and assessed 1) if N-FIN terminated exercise due to the development of a “critical” core temperature (Tc) and 2) whether weight loss of > 3% leads to elevations in Tc. Methods.—Data were collect...

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...

Abstract: 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 follicu...

Objectives. This study investigated the effects of prolonged use of a protein (casein hydrolysate) supplement on perceived muscle soreness and fatigue, in international level Sevens rugby players (n=23) during a pre-season training camp. Methods. A randomised, double-blind, placebo-controlled design was used. Players were assigned to a carbohydrate...

An analysis of Comrades marathon records: A 2008 update

The purpose of this study was to establish and compare the pacing patterns of fast and slow finishers in a tropical ultra-marathon. Data were collected from the Craze Ultra-marathon held on the 22 and 21 of September in 2012 and 2013, respectively. Finishers of the 161-km (N=47) and 101-km (N=120) categories of the race were divided into thirds (Gr...

BACKGROUND: The present study aimed to determine whether consuming a glucose polymer (GP) and fructose would result in increased carbohydrate oxidation rates and improve 40 km time trial performance compared with an isocaloric GP-only drink. METHODS: Eight well-trained male competitive cyclists (VO2max 62.7 ± 9.4 ml/kg/min, power output 5.1 ± 0.6 W...

OBJECTIVES. This study investigated the effects of prolonged use of a protein (casein hydrolysate) supplement on perceived muscle soreness and fatigue, in international level Sevens rugby players (n=23) during a pre-season training camp. METHODS. A randomised, double-blind, placebo-controlled design was used. Players were assigned to a carbohydrate...

This study aimed to examine performance and ratings of physical perceived exertion (P-RPE) and task effort awareness (TEA) during a steady state and 20 km cycling time trial when muscle glycogen concentration at the start of cycling was either “normal” or “high” and during which euglycaemia was maintained throughout by means of a glucose clamp tech...

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 oxida...

IntroductionEnergy systems for endurance and ultra-endurance training and eventsCommon nutritional issues and challengesNutritional strategies to optimise endurance or ultra-endurance trainingAchieving low body fat mass (Table 13.7)Nutrition to enhance immunityGastrointestinal problemsIron deficiencyKey supplements for endurance and ultra-endurance...

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. 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 pe...

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 fo...

This study examined the differences in fat and carbohydrate oxidation during running and cycling at the same relative exercise intensities, with intensity determined in a number of ways. Specifically, exercise intensity was expressed as a percentage of maximum workload (WL(max)), maximum oxygen uptake (%VO(2max)), and maximum heart rate (%HR(max))...

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 fo...

HistoryBiologic process of trainingFactors affecting physical performanceFitness components associated with sportBasic principles of trainingBasic errors in trainingProgram designResistance training for sportGoal settingLimitations to trainingStart easilyTraining intensityTraining structureRegularity of trainingFrequency of trainingTraining duratio...

Objective. The aim of this study was to determine any difference in performance following two different tapering protocols after a period of heavy training. Design. Twelve swimmers who regularly trained at a high volume and intensity were recruited and trained together for 3 weeks. They were then randomly split into two groups (N=6 per group). One...

An analysis of Comrades marathon records: A 2008 update

This review examines the molecular, cellular and physiological effects of magnetic fields with particular reference to the possible effects of magnetism on athletic performance. Magnetic fields have been shown to alter sub-atomic, molecular and cellular parameters, including the hydrogen bonding and solubility of water, enzyme activity, gene expres...

This review provides an update on optimal carbohydrate intake strategies during prolonged exercise. The focus is primarily on the findings of studies performed in the past five years that have investigated the effect of multiple carbohydrate ingestion during prolonged exercise. Specifically, the emphasis is on the new findings related to the ingest...

Increasing inspiratory oxygen tension improves exercise performance. We tested the hypothesis that this is partly due to changes in muscle activation levels while perception of exertion remains unaltered. Eleven male subjects performed two 20-km cycling time-trials, one in hyperoxia (HI, FiO2 40%) and one in normoxia (NORM, FiO2 21%). Every 2km we...

Objective: The aim of this review was to investigate the effects of supplementation with arginine, mainly in combination with aspartate and/or other potentially ergogenic amino acids, on metabolism of substrates, endocrine parameters and performance in endurance and resistance athletes. Data sources: The database PUBMED was consulted, using the fol...

Objectives. The aim of this study was to determine whether the elevated plasma glucose oxidation rate (~ 1.8 g.min-1) in the latter stages of prolonged exercise in subjects in which hyperglycaemia (± 10 mmol.l-1) is maintained via a glucose clamp, improves 100 km cycling time-trial (TT) performance. Design. Seven endurance-trained male cyclists (22...

INTRODUCTION It was quite pleasing to see the discourse that was generated on the topic of pacing. It is an important topic that does not receive a lot of attention in the empirical literature. It was remarkable that Peter Thompson's skill analysis of elite running included four elements, the latter two being perceptual-motor and cognitive in natur...

To examine the relationship between body weight, plasma volume, and serum sodium concentration ([Na]) during prolonged endurance exercise. Observational field study. 2000 South African Ironman Triathlon. 181 male triathletes competing in an Ironman triathlon. Body weight, plasma volume, and serum ([Na]) change from pre- to postrace. Significant bod...

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. T...

The effects of carbohydrate ingestion on prolonged exercise performance have been extensively studied. Particularly, many studies have paid specific attention to the effect of carbohydrate ingestion on time to fatigue, the effect on the respiratory exchange ratio (RER), the effect that the time at which the carbohydrate is ingested may have on perf...

Many coaches who work with endurance athletes still believe in old concepts that can no longer be considered correct. Prime amongst these are the understanding, or misunderstanding, of the concepts of maximal oxygen uptake (V̇DO 2 max), lactate threshold, training heart rate, and dehydration and fluid requirements during prolonged exercise. Knowing...

Objectives. To determine whether an increase in respiratory drive, due to elevated progesterone and oestrogen concentration during various menstrual phases, persists throughout prolonged submaximal exercise and potentially contributes to fatigue. Furthermore, to determine whether the difference in the ventilatory response to exercise from one menst...

Abstract Objectives. To determine whether an increase in respiratory drive, due to elevated progesterone and oestrogen concentration during various menstrual phases, persists throughout prolonged submaximal exercise and potentially contributes to fatigue. Furthermore, to determine whether the difference in the ventilatory response to exercise from...

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 an...

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 20.5 +/- 0.7, 30.0 +/- 1.0, 39.9 +/- 0.9, or 49.4 +/- 1.0 years old at their first race. Each runner's race speed...

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% VO2max, after 48 h on a low CHO diet. The range in improvement i...

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...

Physiological studies of elite and sub-elite black South African runners show that these athletes are typically about 10–12 kg lighter than white athletes and that they are able to sustain higher exercise intensities for longer than white runners. Such superior performance is not a result of higher V O2max values and hence cannot be due to superior...

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 fa...

Seven subjects exercised to exhaustion on a bicycle ergometer at a workload corresponding to an intensity of 70% maximal oxygen uptake (VO2max). On one occasion (FED), subjects consumed a preexercise carbohydrate (CHO) containing breakfast (100 g CHO) 3 h before exercise. On the other occasion (FASTED), subjects exercised after an overnight fast. E...

Euglycemia was maintained in 13 subjects with low muscle glycogen [low glycogen, euglycemic (LGE), n = 8; low glycogen, euglycemic, hyperinsulinemic (LGEI), n = 5] and 6 subjects with normal muscle glycogen (NGE), whereas hyperglycemia was maintained in 8 low muscle glycogen subjects (LGH). All subjects cycled for 145 min at 70% of maximal oxygen u...

Trained cyclists with low muscle glycogen (LGH; n = 8) or normal glycogen (NGH; n = 5) exercised for 145 min at 70% of maximal oxygen uptake during a hyperglycemic clamp. Respiratory exchange ratio was higher in NGH than LGH, and free fatty acid concentrations were lower in NGH than LGH. Areas under the curve for insulin and lactate were lower in L...

This study examined the effects of ingesting 500 ml/h of either a 10% carbohydrate (CHO) drink (CI) or placebo (PI) on splanchnic glucose appearance rate (endogenous + exogenous) (R a), plasma glucose oxidation and muscle glycogen utilisation in 17, non-carbohydrate-loaded, male, endurance-trained cyclists who rode for 180 min at 70% of maximum oxy...

This study compared fuel substrate kinetics in trained cyclists who ingested a 10% carbohydrate (CHO) drink without prior CHO-loading ([NLC] n = 9) with those in cyclists who ingested a water placebo after CHO-loading ([CLP] n = 7) during 180 minutes of cycling at 70% maximum oxygen consumption (Vo2 max). Muscle glycogen at the start of exercise wa...

Previously, we examined the effects of carbohydrate (CHO) ingestion on glucose kinetics during exercise at 70% of maximum O2 uptake (\(\dot V\)O2,max). Here we repeat those studies in heavier cyclists (n=6 per group) cycling for 3 h at a similar absolute O2 uptake but at a lower (55% of\(\dot V\)O2,max) relative exercise intensity. During exercise,...

To determine if bypassing both intestinal absorption and hepatic glucose uptake by intravenous glucose infusion might increase the rate of muscle glucose oxidation above 1 g min–1, ten endurance-trained subjects were studied during 125 min of cycling at 70% of peak oxygen uptake (VO2 peak). During exercise the subjects ingested either a 15 g 100 ml...

This study examined effects of ingesting a 10% carbohydrate (CHO) drink (CI) or placebo (PI) at 500 ml/h on total (splanchnic) glucose appearance (endogenous+exogenous; Ra), blood glucose oxidation, and muscle glycogen utilization in 14 male endurance-trained cyclists who rode for 180 min at 70% of maximal O2 uptake after CHO loading [starting musc...

To determine the limits to oxidation of exogenous glucose by skeletal muscle, the effects of euglycaemia (plasma glucose 5 mM, ET) and hyperglycaemia (plasma glucose 10 mM, HT) on fuel substrate kinetics were evaluated in 12 trained subjects cycling at 70% of maximal oxygen uptake (VO2, max) for 2 h. During exercise, subjects ingested water labelle...

Black athletes currently dominate long-distance running events in South Africa. In an attempt to explain an apparently superior running ability of black South African athletes at distances > 3 km, we compared physiological measurements in the fastest 9 white and 11 black South African middle-to long-distance runners. Whereas both groups ran at a si...