Bengt Saltin's research while affiliated with IT University of Copenhagen and other places

Publications (40)

Article
Several studies using different techniques to estimate muscle blood flow during exercise in humans support the concept that peak muscle perfusion is at least 150 ml/100 g/min. Such high blood flows are achieved when only part of the muscle mass is recruited during exercise. With 2 or more limbs exercising, the pump capacity of the heart will limit...
Article
It is not currently known whether central hemodynamic or peripheral (vascular or metabolic) factors limit maximal oxygen uptake. By measuring the blood flow and oxygen uptake of exercising muscles when only a small fraction of the total muscle mass is engaged in exercise, it has been demonstrated that the skeletal muscle of man could accommodate a...
Article
The relative occurrence of slow twitch (ST) and fast twitch (FTa and FTb) fibres, fibre size, capillary supply, and glycolytic and oxidative enzyme activities in external (EXT) and internal (INT) intercostal muscles was determined on biopsies obtained during thoracotomy from the mid-axillary line in six patients with normal lung function. EXT and I...
Article
ABSTRACT – In 12 patients with paramyotonia congenita, percutaneous needle biopsies from the brachial biceps muscle were performed. Muscle fibre area, distribution of muscle fibre types I, II-A and II-B and capillarization were not different from healthy controls. Signs of myopathy with central nuclei in the muscle cells were noted in 9 of the pati...
Article
Knee extension strength training of one leg (ST) (120 maximal contractions per day, 5 days per week for 9 weeks) was performed by 9 healthy young men. Before and after ST, biopsies were obtained from the vastus lateralis muscle of each leg and static quadriceps contractions (SQC) lasting 2 min were performed with each leg under control conditions a...
Article
Muscle biopsy was taken from the vastus lateralis muscle during surgery of recent fractures of the neck of the femur in 52 patients aged 66-100 years. The percentage of slow twitch (ST) fibres was close to 55% with no significant change with age and no difference between patients with and without clinical diagnoses prior to the fracture. Also subgr...
Article
Twelve men and twelve women 78-81 years of age were studied with muscle biopsies from the right vastus lateralis and biceps brachii and with measurements of isometric and isokinetic strength for knee-extention and isometric strength for elbow-flexion. Bicycle ergometry with determination of heart rate and oxygen uptake at submaximal (50 W) and "max...
Article
A theoretical model is proposed to explain how the increase in mitochondrial protein concentration, and therefore of the oxidative enzymes, that occurs with endurance training could operate to alter the choice of substrate during submaximal exercise in a manner such that the oxidation of fatty acids increases, glycogen depletion and lactate product...
Article
The rather constant amount of glycogen found in all fibre types in human skeletal muscle provides an opportunity to study the pattern of glycogen depletion with exercise, which should give an indication of which fibres are activated to generate the force. In very light dynamic contractions repeated for hours there is a primary reliance on slow twit...
Article
Needle biopsies show relationships between some characteristics of skeletal muscle fibers and athletic performance, but the present data don't establish any of them as predictors of athletic success. Characteristics of human and animal skeletal muscle have received considerable attention in scientific and popular literature. Studies describe the co...
Article
The aerobic and strength requirements in downhill skiing are high, and the authors outline a conditioning program to help the skier meet them.
Article
(1) Local adaptation of skeletal muscles (fibers) only occurs in the extremity involved in the training. (2) Work performance and maximal oxygen uptake were significantly increased only in the trained leg, and the "transfer" to the untrained leg was very small. (3) The classical sign of a training effect with a lowered submaximal heart rate respons...
Article
This description of some of the present knowledge on skeletal muscle fibers, their metabolic potentials, and their interplay with the degree of physical activity has revealed that skeletal muscle of man has a very large capacity for adaptation. Moreover, this adaptability appears to be of utmost importance for the metabolic response as well as for...
Article
The relationship between fiber composition and enzyme profiles as estimated from in vitro enzyme activities has been studied in human skeletal muscle. Samples from the soleus, gastrocnemius, and vastus lateralis muscles were obtained both by biopsying normal subjects and from patients during nonmuscular related general surgery. The samples were ana...
Article
Five trained standardbred horses were studied trotting at two speeds (300 and 500 m × min-1) for 4 h and 1 h, respectively, and one horse at maximal speed. Their mean muscle glycogen content was reduced from 103 to 43 mmol × kg-1 in the 1-h experiment and from 119 to 48 mmol × kg-1 in the 4-h experiment. At maximal trotting speed, muscle glycogen d...
Article
5 male subjects exercised at a mean oxygen uptake of 2.3 1× min-1 (≅ 65 % of Vo2, max) before and after 2 months of physical training for 90 min and 120 min, respectively. Mean maximal oxygen uptake increased by 11 % (p < 0.05), and the mean R-value during the submaximal work decreased from 0.93 to 0.89 (p < 0.01). Plasma levels for FFA and glucose...
Article
LINDHOLM, ARNE and BENGT SALTIN: The physiological and biochemical response of standardbred horses to exercise of varying speed and duration. Acta vet. scand. 1974, 15, 310–324. — Welltrained standardbred horses were studied to examine the metabolic response to excercise of various speeds and duration. Comparisons between interval (400, 700, 1,000...
Chapter
A large number of independent factors may limit man's ability to perform physical work. At the onset of exercise, oxygen uptake increases gradually, and within a couple of minutes, it reaches a new level that is proportional to the performed work. Adipose tissue is the largest source of energy. The adrenergic neurohumoral system is considered to ha...
Article
Full-text available
The relationships among muscle metabolite concentration, exercise intensity, and oxygen utilization were studied under simulated altitude conditions (decompression chamber, 462 mm Hg b.p.). 5 male subjects exercised in 4 min bouts on a cycle ergometer at a wide range of exercise intensities (range 20–114% altitude max Vo2). Oxygen uptake was determ...
Article
Substrate mobilization and utilization are important factors in exercise physiology. Until recently few methods were available for detailed studies of muscle metabolism. The introduction of isotopes for tracing reactions and the use of needles for tissue sampling have resulted in considerable progress in understanding metabolic events. In this pape...
Article
Isolated canine gracilis muscles were perfused in situ with a free flow (systemic blood flow; FF) or a constant flow (blood from a reservoir; CF). The nervous supply was stimulated electrically for 60 min. A-V-concentration differences for glucose, pyruvate, lactate, glycerol, FFA and O2 were obtained as well as the concentrations of ATP, CP, glyco...
Article
Costin, J. C., B. Saltin, N. S. Skinner, Jr. and G. Vastagh, Glucose uptake at rest and during contraction in isolated dog skeletal muscle. Acta physiol. scand. 1971. 81. 124–137.In an in situ isolated canine gracilis muscle preparation the a-v difference for glucose, oxygen, and lactate has been studied at rest and during stimulation. Both free fl...
Article
Full-text available
Bed rest and immobilization effects on oxygen transport system of human body
Chapter
After training reduced blood lactate concentration at a given subniaximal work load is a common finding (2, 3, 11). A more prolonged training period results in a lower blood lactate also at the same relative work load (2, 3, 14). The problem to be focused on in this paper is therefore how the accumulation of the muscle lactate concentration and the...
Article
Skeletal muscle constitutes the major mass of tissue in the human and other mammalian species, and this tissue has an enormous propensity for increasing both aerobic and anaerobic metabolism during contraction. For example, muscular contraction results in an increase in muscle blood flow from 5–10 to 60–70 ml/100 g/min and an increase in oxygen upt...
Article
The dynamics of lactate accumulation in working muscle was studied in three subjects performing maximal bicycle exercise of 2, 6, and 16 min duration. In separate experiments, the two longer maximal work periods were interrupted after 2 min and after 2 and 6 min, respectively. Biopsy specimens from the quadriceps femoris were obtained immediately a...
Article
The acute effects of ingestion of ethanol on the response to submaximal and maximal exercise were studied by noninvasive technics in a group of eight healthy men, ages 21 to 33 (series I). Cardiac output (dye-dilution technic) and intra-arterial pressures were measured in a separate series of experiments in a subgroup of four subjects (series II)....
Article
19 subjects performed prolonged heavy arm and leg exercise after which they had a protein and fat diet for three days. Thereafter they switched to a carbohydrate enriched diet during a 4-day period. The measurements were performed on the 3rd day and then repeated on the 7th day. The glycogen concentration in the thigh and the arm muscles was 4.5 an...
Article
In 6 internationally successful endurance athletes measurements of oxygen uptake, and pulmonary diffusion capacity at maximal bicycle exercise were performed at sea level and after 3 weeks stay at 2250 m altitude (Mexico City). Maximal oxygen uptake was 10–17 % lower at altitude and this reduction was related to the ratio at sea level between DLCO/...
Article
The effects of a 20-day period of bed rest followed by a 55-day period of physical training were studied in five male subjects, aged 19 to 21. Three of the subjects had previously been sedentary, and two of them had been physically active. The studies after bed rest and after physical training were both compared with the initial control studies. Ef...
Article
10 well trained and 10 untrained subjects worked to complete exhaustion on a bicycle ergometer with work loads averaging 77 (76–87) per cent of their individual maximal aerobic power. Determinations of glycogen used by working muscles (biopsy of lateral portion of the quadriceps femoris muscles) and of combusted carbohydrate (Vo2 and RQ) were perfo...

Citations

... In downhill skiing, contractions of the quadriceps are t y p ically of high intensity at slow velocity, and are both concentric and eccentric. 15 In sum, training of the quadriceps should include both static and slow dynamic exercise at high intensity with the dynamic exercise taxing the muscle both concentrically .and eccentrically. ...
... Forty-five years later (at the start of my PhD in 2015), most questions were still unresolved and despite the potential relevance of the muscle typology for sports practice, the muscle typology was not used by sports scientist and practitioners. This was mostly due to the invasiveness of the muscle biopsy technique, which was met with resistance from athletes and resulted in the fact that the biopsy method was used as a research tool only (Gollnick et al., 1980). With the advent of newly developed techniques to non-invasively estimate muscle typology, such as through the measurement of the FT muscle metabolite carnosine by proton magnetic resonance spectroscopy, this hurdle is disappearing. ...
... In our study, HR peak and VO 2peak were significantly higher during T1 with the 3 min speed increment which started at 40 AE 2.5% vVO 2peak than T2 with the 2 min speed increment and initial velocity at 61 AE 5.0% of vVO 2peak . Although there are several physiological differences in equines and humans (Art, 2011), we suspected that the high initial velocity in T2 induced earlier peak cardiac responses and impacted on exercise tolerance and fatigue assessment in our trotters, as it was documented in humans (Saltin et al., 1968; Bassett and Howley, 1997). Our results confirmed that peak cardiorespiratory responses of trotters are influenced by the incremental field test design, which need to be carefully selected depending on the variables that will be measured. ...
... The activation of this enzyme is triggered by increasing catecholamines, muscle contraction or both (Tarrant 1989). Increased metabolism of muscle glycogen during stress may be a direct result of the calcium release into the myofibril associated with muscle contraction (Rosell & Saltin 1973). On the other hand, increasing catecholamines levels can also activate glycolysis (Drummond et al. 1969). ...
... One function is that a smaller disruption in homeostasis occurs within contracting skeletal muscles with higher mitochondrial concentrations (Holloszy & Booth, 1976). For example, when the same human is tested at the same submaximal O 2 consumption before and after endurance training, glycogen depletion and lactate concentrations in the quadriceps muscle are lower (Saltin & Karlsson, 1971). Trained muscles oxide more fatty acids (sparing the limited stores of glycogen) at the same absolute workload with a resultant protection against hypoglycaemia-induced fatigue and a longer exercise-time to exhaustion (Holloszy & Coyle 1984;Saltin & Åstrand, 1993). ...
... The same series of studies further reported that end-systolic elastance and contractility were also preserved during maximal exercise up to 7620 m (Suarez et al., 1987). Moreover, stroke volume is not restored with acute supplementary oxygen at 4300 m (Saltin et al., 1968), indicating that oxygen tension is not solely responsible for the reduced stroke volume at altitude, or at least that any such oxygen-dependent alteration to stroke volume ...
... Indeed, those with a "scooped" MEFV curve (i.e., convex relative to the x-axis) have a greater propensity towards EFL during exercise and the shape does not differ based on sex [77]. Aerobic fitness may also impact EFL since aerobically trained individuals generate a greater V E during maximal exercise than untrained individuals but have similar levels of pulmonary function [78]. Since the shape of the MEFV curve and the ability to increase aerobic fitness are similar in males and females, EFL propensity during exercise is also similar between the sexes in healthy adults of average aerobic fitness [10,25,79]. ...
... Overall, physical activity did not influence fat oxidation in the Danes so that the marked differences expressed as the respiratory exchange ratio were thought to be due to differences in diet intake (Saltin, 2013). His interests also extended to animals under different environmental and stress conditions including horses (Asheim et al., 1970), dogs (Costin et al., 1971) as well as racing camels (Saltin & Rose, 1994), and in turn expanding his understanding of integrative physiology of mammals in general. ...
... Muscle biopsies of non-dystrophic myotonias were initially described as normal or showing mild, non-specific abnormalities [8]. Subsequent investigations reported an absence of type 2B fibres in chloride channelopathies, while patients with paramyotonia congenita, a sodium channelopathy, were found to show intracellular large vacuoles and tubular aggregates [9][10][11]. However, the presence of muscle changes has never been systematically investigated in large group of genetically confirmed patients. ...
... A large cross-sectional area is important to develop maximal force, and a correlation has been found between a larger muscular cross-sectional area around the medial area of the knee and an improved performance time in the 100 m sprint [26]. A high proportion of type 2 muscle fibers is necessary to develop force quickly, which, in turn, affects sprinting performance [27,28]. Longer muscle fibers contract quicker, and there is a correlation between long muscle fibers and an improved performance over 100 m [29][30][31]. ...