David L Costill

Ball State University · School of Physical Education, Sport, and Exercise Science

No abstract is available.

Our primary goal was to determine the effects of six-month flight on the International Space Station (ISS) on selected anaerobic and aerobic enzymes, and the content of glycogen and lipids in slow and fast fibers of the soleus and gastrocnemius. Following local anesthesia, biopsies were obtained from nine ISS crew members ~45 days pre- and on landi...

Cardiorespiratory responses during marathon running (42.2 km) were estimated on nine nationally ranked marathon athletes. Oxygen consumption ([vdot]o2), ventilation ([vdot]E), and heart rate (HR) were predicted from competitive data (average speed) using individual regression equations derived from steady-state values measured in the laboratory. Fr...

The purpose of this investigation was to examine day-to-day variations in metabolic measurements during submaximal exercise. Ten male subjects (five cyclists, five runners) randomly performed four cycling (CYC) and four running (RUN) trials. CYC trials were conducted on a bicycle ergometer at 100 W, 150 W, and 200 W; and RUN trials at treadmill vel...

This paper examines the contribution of exercise physiology research to improvements in sports performance. By using illustrations from studies on competitive swimmers, attempts have been made to show the need to develop tests that evaluate the factors essential for success in sports. Such testing should be used to describe the strengths and weakne...

Fitts RH. Exercise in space: human skeletal muscle after 6 months aboard the International Space Station. J Appl Physiol 2009; 106: 1159-68.

The primary goal of this study was to determine the effects of prolonged space flight (∼180 days) on the structure and function of slow and fast fibres in human skeletal muscle. Biopsies were obtained from the gastrocnemius and soleus muscles of nine International Space Station crew members ∼45 days pre- and on landing day (R+0) post-flight. The ma...

The aim of this investigation was to document the exercise program used by crewmembers (n = 9; 45 +/- 2 yr) while aboard the International Space Station (ISS) for 6 mo and examine its effectiveness for preserving calf muscle characteristics. Before and after spaceflight, we assessed calf muscle volume (MRI), static and dynamic calf muscle performan...

In the late 1960s and early 1970s, endurance running was gaining popularity at an exponential rate. Paul Milvy organised the scientific and medical conference entitled 'The Marathon: Physiological, Medical, Epidemiological, and Psychological Studies' associated with 1976 New York Marathon and sponsored by the New York Academy of Sciences to provide...

To determine the influence of a 17-day exposure to real and simulated spaceflight (SF) on cardiorespiratory function during exercise, four male crewmembers of the STS-78 space shuttle flight and eight male volunteers were studied before, during, and after the 17-day mission and 17 days of -6 degrees head-down-tilt bed rest (BR), respectively. Measu...

The significance and relevance of the topics being discussed in this text is under scored by Westerhoff’s (2000) suggestion that biochemistry is poised to make major advances in this century, similar to those made in physics in the 20th century. He anticipates that, to understand the nonlinear kinetic interactions between molecules and interpret th...

We used Ca2+-activated skinned muscle fibers to test the hypothesis that unilateral lower leg suspension (ULLS) alters cross-bridge mechanisms of muscle contraction. Soleus and gastrocnemius biopsies were obtained from eight subjects before ULLS, immediately after 12 days of ULLS (post-0 h), and after 6 h of reambulation (post-6 h). Post-0 h soleus...

Slow type I fibers in soleus and fast white (IIa/IIx, IIx), fast red (IIa), and slow red (I) fibers in gastrocnemius were examined electron microscopically and physiologically from pre- and postflight biopsies of four astronauts from the 17-day, Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission. At 2.5-microm sarcomere len...

Renal insufficiency is associated with altered vitamin B-6 metabolism. We have observed high concentrations of 4-pyridoxic acid, the major catabolite of vitamin B-6 metabolism, in plasma during renal insufficiency. The objective was to evaluate the renal handling of 4-pyridoxic acid and the effects of renal dysfunction on vitamin B-6 metabolism. We...

The purpose of this investigation was to assess muscle fiber size, composition, and in vivo contractile characteristics of the calf muscle of four male crew members during a 17-day spaceflight (SF; Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission) and eight men during a 17-day bed rest (BR). The protocols and timelines of...

The purpose of this investigation was to study the effects of a 17-day spaceflight on the contractile properties of individual fast- and slow-twitch fibers isolated from biopsies of the fast-twitch gastrocnemius muscle of four male astronauts. Single chemically skinned fibers were studied during maximal Ca2+-activated contractions with fiber myosin...

In an effort to measure strength characteristics of the calf muscles, 18 subjects (14 male, 4 female, age =34.3+/-2.4yrs) were tested using a specially designed torque velocity device (TVD). This TVD is a hardware interface with the subject's lower leg which stabilizes the leg for calf muscle strength measurements. Calf muscle strength measurements...

TRAPPE, S., D. COSTILL, and R. THOMAS. Effect of swim taper on whole muscle and single muscle fiber contractile properties. Med. Sci. Sports Exerc., Vol. 32, No. 12, 2000, pp. 48-56. Purpose: To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly traine...

To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly trained swimmers before and after a 21-d reduction in training volume (taper). Six college male swimmers (age, 20+/-1 yr; height, 187+/-2 cm, weight, 79+/-3 kg, fat, 7+/-1%) who had been, on average...

The purpose of this study was to examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older men (n = 7; age = 74 +/- 2 yr and weight = 75 +/- 5 kg). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsy samples were obtained from the vastu...

This investigation examined the effects of 4 weeks of non-dominant arm unloading on the functional and structural characteristics of the triceps brachii muscle of six normo-active college-age males (age: 23 +/- 1 years, height: 176 +/- 4 cm, weight: 76 +/- 6 kg). The primary intention of this study was to determine if arm unloading is an effective...

The purpose of this study was to examine myosin heavy chain (MHC) and myosin light chain (MLC) isoforms following 12 wk of progressive resistance training (PRT). A needle biopsy was taken from the vastus lateralis to determine fiber-type expression [ATPase (pH 4.54) and MHC/MLC] in seven healthy men (age = 74.0 +/- 1.8 yr). Subjects were also teste...

Soleus muscle fibers were examined electron microscopically from pre- and postflight biopsies of four astronauts orbited for 17 days during the Life and Microgravity Sciences Spacelab Mission (June 1996). Myofilament density and spacing were normalized to a 2.4-μm sarcomere length. Thick filament density (,1,062 filaments/μm2) and spacing (,32.5 nm...

Astronauts that experienced reductions in both fibre diameter and Po/CSA displayed a drop in peak force that was 2-3 times greater than observed for the astronauts experiencing only one of these changes. As discussed below, this has important implications regarding fibre power output following the flight. Furthermore, a reduction in force productio...

The purpose of this study was to examine the effect of a decreased body core temperature before a simulated portion of a triathlon (swim,15 min; bike, 45 min) and examine whether precooling could attenuate thermal strain and increase subjective exercise tolerance in a warm environment (26.6 degrees C/60% relative humidity (rh)). Six endurance train...

Exposure to microgravity or models designed to mimic the unloaded condition, such as bed rest in humans and hindlimb unloading (HU) in rats leads to skeletal muscle atrophy, a loss in peak force and power, and an increased susceptibility to fatigue. The posterior compartment muscles of the lower leg (calf muscle group) appear to be particularly sus...

Soleus muscle fibers from the rat display a reduction in peak power and Ca2+ sensitivity after hindlimb suspension. To examine human responses to non-weight bearing, we obtained soleus biopsies from eight adult men before and immediately after 17 days of bed rest (BR). Single chemically skinned fibers were mounted between a force transducer and a s...

Previously we reported that, after 17-day bed rest unloading of 8 humans, soleus slow fibers atrophied and exhibited increased velocity of shortening without fast myosin expression. The present ultrastructural study examined fibers from the same muscle biopsies to determine whether decreased myofilament packing density accounted for the observed sp...

Previously we reported that, after 17-day bed rest unloading of 8 humans, soleus slow fibers atrophied and exhibited increased velocity of shortening without fast myosin expression. The present ultrastructural study examined fibers from the same muscle biopsies to determine whether decreased myofilament packing density accounted for the observed sp...

The purpose of this study was to examine the effect of prolonged bed rest (BR) on the peak isometric force (P0) and unloaded shortening velocity (V0) of single Ca(2+)-activated muscle fibers. Soleus muscle biopsies were obtained from eight adult males before and after 17 days of 6 degrees head-down BR. Chemically permeabilized single fiber segments...

This study examined the effects of wearing a helmet on selected body temperatures and perceived heat sensation of the head and body while cycling in a hot-dry (D) (35 degrees C, 20% relative humidity (RH) and hot-humid (H) (35 degrees C, 70% RH) environment. Ten male and four female cyclists (mean +/- SD: males = age 27 +/- 7 yr, peak O2 uptake (VO...

This investigation was undertaken to determine whether consuming several small feedings of preexercise carbohydrate (CHO), rather than a single bolus, would affect blood glucose and insulin responses during rest and exercise. Eight trained cyclists ingested 22.5, 45, or 75 total g maltodextrin and dextrose dissolved in 473 ml of water or an equal v...

The purpose of this investigation was to examine the effects of diet on muscle triglyceride and endurance performance. Seven endurance-trained men completed a 120-min cycling bout at 65% of maximal oxygen uptake. Each subject then ingested an isocaloric high-carbohydrate (Hi-CHO; 83% of energy) or a high-fat (Hi-Fat; 68% of energy) diet for the ens...

Ten competitive male cyclists completed a Wingate Bike Test (WIN), a 30-min self-paced cycling performance bout (END), and a constant load, supramaximal cycling spring (SPN) to fatigue following 5 d of oral supplementation (5,000 mg.day-1) with inosine and placebo. Blood samples were obtained prior to and following both supplementation periods, and...

The purpose of this investigation was to examine calf muscle strength and cross-sectional area in 29 middle-aged men (current mean = 48.3 +/- 3.1 years) who had significant differences in their physical activity levels. These men were initially evaluated to determine the physiological requirements for successful distance running in the late 1960s a...

Fifty-six men aged 42-73 years (50.2 +/- 10.0 years), who were competitive distance runners 20-25 years previously, were examined for bone mineral density (BMD) to determine the relationship between sustained distance running and BMD. Subjects were classified as being highly trained (HT, n = 17), moderately trained (MT, n = 29) or untrained (UT, n...

Single chemically permeabilized gastrocnemius fibers from six elite endurance-trained master runners (RUN group) and five age-matched sedentary controls (SED group) were mounted between a force transducer and a position motor, studied under conditions of maximal and submaximal Ca2+ activation, and subsequently electrophoresed on 5% polyacrylamide g...

Gastrocnemius muscle fiber bundles were obtained by needle biopsy from five middle-aged sedentary men (SED group) and six age-matched endurance-trained master runners (RUN group). A single chemically permeabilized fiber segment was mounted between a force transducer and a position motor, subjected to a series of isotonic contractions at maximal Ca2...

This study compared the physiological responses and performance following the ingestion of a waxy starch (WS), resistant starch (RS), glucose (GL) and an artificially-sweetened placebo (PL) ingested prior to exercise. Ten college-age, male competitive cyclists completed four experimental protocols consisting of a 30 min isokinetic, self-paced perfo...

The present study was designed to evaluate the influence of starch structure on muscle glycogen resynthesis and cycling performance. Eight male cyclists (22 +/- 1 yr) completed an exercise protocol (DP) to decrease vastus lateralis glycogen concentration. This exercise consisted of 60 min cycling at 75% VO2max, followed by six 1-min sprints at appr...

This report summarizes the health behaviors and psychological characteristics of fifteen male marathon runners who were first tested in 1969 (N = 8) and 1976 (N = 7). The participants in this study averaged 29 years of age at the outset, and the mean age at the time of follow-up was 50 years. These subjects were found to score in the normal range o...

Ten competitive male cyclists completed a Wingate Bike Test (WIN), a 30-min self-paced cycling performance bout (END), and a constant load, supramaximal cycling sprint (SPN) to fatigue following 5 d of oral supplementation (5,000 mg.day -1 ) with inosine and placebo. Blood samples were obtained prior to and following both supplementation periods, a...

Seven highly trained male college distance runners were studied throughout a competitive cross-country season. Common laboratory and field measurements were used to assess their physiological adaptation to training. They were tested before (pre), during (mid), and at the end of the competitive season (post) for peak oxygen consumption (V̇O2peak), r...

The purpose of this investigation was to determine the effect of caffeine ingestion on work output at various levels of perceived exertion during 30 min of isokinetic variable-resistance cycling exercise. Ten subjects completed six trials 1 hr after consuming either 6 mg.kg-1 caffeine (3 trials) or a placebo (3 trials). During each trial the subjec...

The purpose of this study was to assess the physiological responses of former elite distance runners during submaximal and maximal exercise after a mean period of 22 yr. Fifty-three men were initially tested (T1) in the late 1960s and early 1970s when they were all highly trained and competitive. For the current evaluation (T2), these men were clas...

Vitamin B-6 metabolism in 10 volunteers during 21 d of total fasting was compared with results from 10 men consuming a diet low only in vitamin B-6 (1.76 mumol/d) and with men consuming a normal diet during bed rest. At the end of the fast mean plasma concentrations of vitamin B-6 metabolites and urinary excretion of 4-pyridoxic acid tended to be h...

In order to determine the effect of oral Coenzyme Q10 (CoQ10) dosing on exercise capacity, 15 middle-aged men (44.7 +/- 2.0 years) received either CoQ10 (150 mg/day x 2 months-Q10 GRP) or placebo (2 months-CON GRP). Blood CoQ10 levels increased (p < 0.05) during the treatment in the Q10 GRP (Pre = 0.72 +/- 0.06, 2 months = 1.08 +/- 0.14 micrograms/...