Short Intense Exercise Research Articles

Beyond bronchodilation: Illuminating the performance benefits of inhaled beta2‐agonists in sports

AbstractGiven the prevalent use of inhaled beta2‐agonists in sports, there is an ongoing debate as to whether they enhance athletic performance. Over the last decades, inhaled beta2‐agonists have been claimed not to enhance performance with little consideration of dose or exercise modality. In contrast, orally administered beta2‐agonists are perceived as being performance enhancing, predominantly on muscle strength and sprint ability, but can also induce muscle hypertrophy and slow‐to‐fast fiber phenotypic switching. But because inhaled beta2‐agonists are more efficient to achieve high systemic concentrations than oral delivery relative to dose, it follows that the inhaled route has the potential to enhance performance too. The question is at which inhaled doses such effects occur. While supratherapeutic doses of inhaled beta2‐agonists enhance muscle strength and short intense exercise performance, effects at low therapeutic doses are less apparent. However, even high therapeutic inhaled doses of commonly used beta2‐agonists have been shown to induce muscle hypertrophy and to enhance sprint performance. This is concerning from an anti‐doping perspective. In this paper, we raise awareness of the circumstances under which inhaled beta2‐agonists can constitute a performance‐enhancing benefit.

#3594 CHANGES IN ALBUMINURIA AND KIDNEY FUNCTION AFTER 8 WEEK HIGH-INTENSITY INTERVAL TRAINING PROGRAM IN 2ND AND 3RD TRIMESTER OF PHYSIOLOGICAL PREGNANCY

Abstract Background and Aims Physical exercise is the best prophylaxis of many disorders and should be continued during uncomplicated pregnancy. Several studies suggested that most pregnant women had no contraindications to perform intensive exercises. In recently published studies the beneficial effect of high-intensity interval training (HIIT) on both mental health and reduction of excessive weight gain during pregnancy has been demonstrated. The knowledge regarding kidney function after exercise in pregnancy is very scarce and only few studies concerning this topic were published. The aim of this study was to estimate changes in markers of kidney function in healthy pregnant exercising women. Changes after single intensive exercise and after 8 week training program were analyzed. Method The group of 36 women in 2nd and 3rd trimester of pregnancy were recruited to the study. At the beginning of the study all participants had normal kidney function (serum creatinine level below 0.6 mg/dl) and albuminuria (uACR below 30 mg/g) in rest. 19 women participated in 8-week HIIT program and 17 women in 8-week educational program (EDU group). Before and after 8 week training and education programs a progressive maximal exercise test on cyclometer was performed. Several biochemical measurements were performed. Results Women from both groups revealed mild changes concerning kidney function in rest, typical for physiological pregnancy (e.g. low sodium, creatinine and uric acid levels). After progressive maximal exercise test some unexpected findings were found: the fractional excretion of urea and uric acid increased (FeUrea from 41.25 to 50.05%; FeUA from 7.18 to 8.04%) and serum uric acid decreased significantly (sUA from 3.35 to 3.28mg/dL). Other changes after short exercise were typical: significant increase of uACR (from 5.12 to 9.43mg/g), serum creatinine (from 0.52 to 0.56mg/dL) and urea (from 16.45 to 21.65 mg/dL), among others. The 8-week HIIT training program did not change kidney function in rest. In both groups a significant increase of eCrCl and sUA were observed. The interesting observation was that uACR increased significantly only in EDU group. Conclusion Changes in kidney function after short intensive exercise in pregnancy were typical for healthy subjects, but there was no negative impact on markers of renal hypoperfusion. It was probably related to increased renal blood flow occurring in healthy pregnancy. The supervised 8-week HIIT training program had no negative impact on kidney function. The possible positive impact of this training on albuminuria was suggested.

Enhancing Children's Motor Memory Retention Through Acute Intense Exercise: Effects of Different Exercise Durations.

Physical exercise has been proposed as a viable means to stimulate motor learning. Exercise characteristics, including intensity and duration, may play a role in modulating the exercise effect on motor learning. While some evidence exists regarding the benefits of intense and relatively long exercise, little is known about the effect of short exercise bouts on motor learning, especially in children. This study aimed to assess the effect of long versus short intense exercise bouts on the adaptation and consolidation of a rotational visuomotor adaptation task. The participants were 71 healthy children from two sites divided into three groups: long exercise bout (LONG), short exercise bout (SHORT), and no exercise (CON). Children performed a rotated (clockwise 60° rotation) motor task on four different occasions: an adaptation set and 1 h, 24 h, and 7 days delayed retention sets. Exercise bouts were performed prior to the adaptation set. Results showed a group effect during motor adaptation [F(2,68) = 3.160; p = 0.049; = 0.087], but no statistical differences were found between groups. Regarding retention tests, both exercise groups (LONG and SHORT) showed superior retention compared to CON group [F(2,68) = 7.102; p = 0.002; = 0.175]. No differences were found between exercise groups, indicating similar benefits for the two exercise interventions. Overall, whether the exercise duration was long or short, exercise improved motor memory retention as an estimate of memory consolidation process. The use of short exercise bouts may be suitable to improve children’s motor memory consolidation in environments where time constraints exist.

Simultaneous analysis of neopterin, kynurenine and tryptophan by amine-HPLC shows minor oxidative stress from short-term exhaustion exercise

Abstract Introduction: Neopterin, kynurenine and tryptophan can be used to measure activation of monocytes and macrophages during immunological events such as exercise inducing inflammation. Endurance exercise and high-impact sports have shown significant increases in these biomarkers. Measurement is typically conducted by high-performance liquid chromatography (HPLC) using C18 or SCX columns. However, kynurenine and tryptophan are not measured simultaneously to neopterin using these separation systems. Here we have used an amine column for separation and simultaneous determination of neopterin, kynurenine and tryptophan. Methods: Optimization and validation for the amine-HPLC method was conducted using plasma from 43 participants subjected to a short maximal exercise bicycling regime or rest period. The order of exercise and rest was randomized and separated by a 3-5 week washout period. Results: Using an amine column developed with ammonium acetate formic acid (33%) and acetonitrile (72%) provided optimal separation and run time for analysis. Neopterin increased significantly post-exercise and subsided to baseline by 30 minutes. Total neopterin remained elevated until 60 minutes following exercise. Conclusion: Amine-HPLC can be used for simultaneous determination of kynurenine, tryptophan and neopterin in plasma. Short intense exercise causes a significant increase in plasma neopterin suggesting a prolonged activation of monocytes and macrophages.

The effects of short intensive exercise on plasma free amino acids in standardbred trotters

The aim of this study was to investigate the effect of short intense exercise on plasma amino acid concentrations in trotters and to test the repeatability of plasma amino acids concentration in samples obtained on two independent days under field conditions. Plasma amino acid concentrations were analysed in blood samples of 36 standardbred trotters before and after intense exercise over a distance of 2000 m. Sampling was repeated in 20 horses after 35 days. Exercise intensity was estimated from post-exercise lactate levels. Horses were divided in two groups according to a cut-off lactate concentration at 15 mmol/l. The plasma concentrations of alanine, aspartate, glutamate, isoleucine, leucine, lysine and taurine increased and arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan and 3-methylhistidine decreased after exercise. Ornithine, threonine, tyrosine, phenylalanine and valine concentrations remained constant. Higher intensity of exercise significantly decreased tryptophan and increased taurine concentrations. Sampling day had a significant effect on the absolute pre- and post-exercise amino acid concentrations. Exercise had a significant influence on the concentrations of most plasma amino acids in trotters. These changes could reflect shifts between the free amino acid compartments, but there were also some indications for muscle catabolism. The amino acid supply of sporting horses could be of specific significance for maintaining muscle integrity and for the improvement of post-exercise recovery of competition horses.

Short intensive exercise increases the migratory activity of mesenchymal stem cells

Background:It is known that exercise increases the number of stem cells within the circulation; however, it has not been clear which cellular processes are responsible for this increase. To answer...

Effects of active recovery between series on performance during an intermittent exercise model in young endurance athletes

The purpose of our study was to compare time to exhaustion ( t(lim)) and time spent at a high level of oxygen uptake (V(.)O(2)) during two high-intensity short intermittent exercises (30 s-30 s) realized with or without series. Eleven young endurance-trained athletes [16.6 (0.4) years] took part in three field tests until exhaustion: (1) a maximal graded test to measure their maximal aerobic velocity (MAV) and maximal oxygen uptake (V(.)O(2max)); (2) and (3) two randomized intermittent exercises (30 s at 110% of MAV alternated with 30 s at 50% of MAV): one alternating repetitions non-stop (IE) and another including 4 min recovery every six repetitions (IEs). The mean t(lim) measured during IEs was significantly longer than IE [respectively 960.0 (102.0) s vs 621.8 (56.2) s]. The time spent at V(.)O(2max)( t(V(.)O2max)) and the time spent above 90% of V(.)O(2max)( t(90%V(.)O2max)) did not differ significantly according to the type of exercise: with or without series [respectively t(V(.)O2max) was 158.2 (59.7) s vs 178.0 (56.5) s and t(90%<Vdot>O2max) was 290.4 (84.3) s vs 345.0 (61.6) s] but when expressed as a relative value, t(90%<Vdot>O2max) during IEs was significantly lower than during IE [respectively 36.4 (10.4)% t(lim) vs 58.3 (8.7)% t(lim)]. Despite a significant decrease ( P<0.005) of time to achieve 90% of V(.)O(2max) at the start of each series during IEs [respectively 165.0 (43.1) s for the first series and 82.5 (15.8) s for the second series ( n=6)] the time spent under 90% of V(.)O(2max) limited the t(90%V(.)O2max) during each series. In conclusion, our results showed that intermittent exercise with series does not permit an increase in the time spent at a high level of V(.)O(2); however, the athletes performed more repetitions of short intense exercise.