Water immersion methods do not alter muscle damage and inflammation biomarkers after high-intensity sprinting and jumping exercise.

PURPOSE: The aim of this study was to compare the efficacy of three water immersion interventions performed after active recovery compared to active recovery only on the resolution of inflammation and markers of muscle damage post-exercise. METHODS: Nine physically active men (n = 9; age 20‒35 years) performed an intensive loading protocol, including maximal jumps and sprinting on four occasions. After each trial, one of three recovery interventions (10 min duration) was used in a random order: cold-water immersion (CWI, 10 °C), thermoneutral water immersion (TWI, 24 °C), contrast water therapy (CWT, alternately 10 °C and 38 °C). All of these methods were performed after an active recovery (10 min bicycle ergometer), and were compared to active recovery only (ACT). 5 min, 1, 24, 48, and 96 h after exercise bouts, immune response and recovery were assessed through leukocyte subsets, monocyte chemoattractant protein-1, myoglobin and high-sensitivity C-reactive protein concentrations. RESULTS: Significant changes in all blood markers occurred at post-loading (p < 0.05), but there were no significant differences observed in the recovery between methods. However, retrospective analysis revealed significant trial-order effects for myoglobin and neutrophils (p < 0.01). Only lymphocytes displayed satisfactory reliability in the exercise response, with intraclass correlation coefficient > 0.5. CONCLUSIONS: The recovery methods did not affect the resolution of inflammatory and immune responses after high-intensity sprinting and jumping exercise. It is notable that the biomarker responses were variable within individuals. Thus, the lack of differences between recovery methods may have been influenced by the reliability of exercise-induced biomarker responses.

Sprint mechanics evaluation using inertial sensor-based technology: A laboratory validation study.

Advances in micro-electromechanical systems have turned magnetic inertial measurement units (MIMUs) into a suitable tool for vertical jumping biomechanical evaluation. Thus, this study aimed to determine whether appropriate reliability and agreement reports could also be obtained when analyzing 20-m sprint mechanics. Four bouts of 20-m sprints were evaluated to determine whether the data provided by a MIMU placed at the lumbar spine could reliably assess sprint mechanics and to examine the validity of the MIMU sensor compared to force plate recordings. Maximal power (P0 ), force (F0 ), and velocity (V0 ), as well as other mechanical determinants of sprint performance associated with the force-velocity, power-velocity, and ratio of forces-velocity, such as applied horizontal force loss (Sfv ) and decrease in ratio of forces (Drf ), were calculated and compared between instrumentations. Extremely large-to-very large correlation levels between MIMU sensor-based sprint mechanics variables and force plate recordings were obtained (mean±SD, force plate vs MIMU; V0, 8.61±0.85 vs 8.42±0.69; F0 , 383±110 vs 391±103; P0 , 873±246 vs 799±241; Sfv, -44.6±12.7 vs -46.2±10.7), ranging from 0.88 to 0.94, except for Drf, which showed weak-to-moderate correlation level (r=.45; -6.32±1.08 vs -5.76±0.68). Step-averaged force values measured with both systems were highly correlated (r=.88), with a regression slope close to the identity (1.01). Bland and Altman graphical representation showed a no random distribution of measured force values. Finally, very large-to-extremely large retest correlation coefficients were found for the intertrial reliability of MIMU measurements of sprint performance variables (r value ranging from .72 to .96). Therefore, MIMUs showed appropriate validity and reliability values for 20-m sprint performance variables.

Combined aerobic and resistance training decreases inflammation markers in healthy men.

Our primary aim was to study the effects of 24 weeks of combined aerobic and resistance training performed on the same day or on different days on inflammation markers. Physically active, healthy young men were randomly divided into three groups that performed: aerobic and resistance training consecutively in the same training session (SS) 2-3 days wk-1 or on alternating days (AD) 4-6 days wk-1 as well as control (C). The total training volume was matched in the training groups. The control group was asked to maintain their habitual physical activity and exercise level. Maximal leg press strength (1RM) and peak oxygen uptake (VO2peak ) were measured. Abdominal fat mass was estimated with dual-energy absorptiometry (DXA). High-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), and adipocytokines resistin, adiponectin, and leptin were analyzed from plasma samples. Training significantly reduced circulating hs-CRP, leptin, and resistin in both training groups (P<.05), whereas MCP-1 and TNF-α decreased only in AD (P<.05). Significant correlations were observed between changes in abdominal fat mass and corresponding changes in MCP-1, leptin, adiponectin, and resistin. Long-term combined aerobic and resistance training reduced markers of subclinical inflammation in healthy young men. The results indicate that a higher frequency of individual exercise sessions might be more beneficial with respect to the anti-inflammatory effects of physical activity. The decreases in inflammation markers seem to be related to decreases in abdominal fat mass.

Resistance training induced increase in muscle fiber size in young and older men.

Muscle strength and mass decline in sedentary individuals with aging. The present study investigated the effects of both age and 21 weeks of progressive hypertrophic resistance training (RT) on skeletal muscle size and strength, and on myostatin and myogenin mRNA expression in 21 previously untrained young men (26.0 ± 4.3 years) and 18 older men (61.2 ± 4.1 years) and age-matched controls. Vastus lateralis muscle biopsies were taken before and after RT. Type I and type II muscle fiber cross-sectional areas increased more in young men than in older men after RT (P < 0.05). Concentric leg extension increased (P < 0.05) more after 10.5 weeks in young men compared to older men, but after 21 weeks no statistical differences existed. The daily energy and protein intake were greater (P < 0.001) in young subjects. Both myostatin and myogenin mRNA expression increased in older when compared with young men after RT (P < 0.05). In conclusion, after RT, muscle fiber size increased less in older compared to young men. This was associated with lower protein and energy intake and increases in myostatin gene expression in older when compared to young men.

Effects of resistance exercise and protein ingestion on blood leukocytes and platelets in young and older men.

This study investigated, in a multi-experiment design, the acute effects of milk protein ingestion, aging [50 young (approximately 26 years) vs. 45 older (approximately 61 years) men] and training state for the blood leukocyte and platelet responses acutely after a single bout of resistance exercise (RE). Moreover, basal effects of 21 weeks of resistance training (RT) were examined. The single bout of RE rapidly increased all blood leukocytes and platelets (P < 0.05). Protein ingestion before or before and after the RE bout did not have an effect on this response. However, younger men had a larger immediate exercise-induced response in leukocytes and platelets than older men. Basal fasting levels of leukocytes and platelets remained unchanged after 21 weeks of RT and this RT period did not change the acute RE-induced leukocyte and platelet response. The long-term RT was, however, able to slightly increase blood hematocrit. Blood platelet counts were consistently higher in the younger men when compared to the older men. Blood lymphopenia occurred only after a larger volume of exercise. In conclusion, the acute increase in blood leukocytes and platelets may be smaller in the older as when compared to the younger men. However, the number of immune cells and thus probably their function may not be affected by milk protein ingestion or months of resistance training.

Strength, [corrected] endurance or combined training elicit diverse skeletal muscle myosin heavy chain isoform proportion but unaltered androgen receptor concentration in older men.

We investigated whether the myosin heavy chain (MyHC) proportion and androgen receptor (AR) concentration in skeletal muscle differ following 21 weeks of strength, endurance and combined training in untrained older men. Strength (S) and endurance (E) groups trained twice per week and combined (S+E) group trained four times per week (two strength and two endurance). Muscle biopsies were obtained before and after the training period from m. vastus lateralis (VL) and AR mRNA and protein concentration and MyHC proportion were determined. 1RM increased during the training period in S, S+E and E but the changes were greater in S and S+E than in E. Statistically significant increases were observed only in S and S+E in maximal isometric force as well as in VL thickness. VO (2max) increased significantly only in E. MyHCIIa proportion increased in S, while MyHCIIa proportion decreased and MyHCI increased (p<0.05) in E. No statistically significant changes were observed in serum testosterone and in AR mRNA or protein concentrations. The present results indicate that 21 weeks of strength, endurance or combined training changed MyHC proportion according to the training method but did not have an effect on AR mRNA or protein expression in skeletal muscle at rest.

Autophagy is induced by resistance exercise in young men, but unfolded protein response is induced regardless of age.

AIM: Autophagy and unfolded protein response (UPR) appear to be important for skeletal muscle homoeostasis and may be altered by exercise. Our aim was to investigate the effects of resistance exercise and training on indicators of UPR and autophagy in healthy untrained young men (n = 12, 27 ± 4 years) and older men (n = 8, 61 ± 6 years) as well as in resistance-trained individuals (n = 15, 25 ± 5 years). METHODS: Indicators of autophagy and UPR were investigated from the muscle biopsies after a single resistance exercise bout and after 21 weeks of resistance training. RESULTS: Lipidated LC3II as an indicator of autophagosome content increased at 48 hours post-resistance exercise (P < .05) and after a resistance training period (P < .01) in untrained young men but not in older men. Several UPRER markers, typically induced by protein misfolding in endoplasmic reticulum, were increased at 48 hours post-resistance exercise in untrained young and older men (P < .05) but were unaltered after the 21-week resistance training period regardless of age. UPR was unchanged within the first few hours after the resistance exercise bout regardless of the training status. Changes in autophagy and UPRER indicators did not correlate with a resistance training-induced increase in muscle strength and size. CONCLUSION: Autophagosome content is increased by resistance training in young previously untrained men, but this response may be blunted by ageing. However, unfolded protein response is induced by an unaccustomed resistance exercise bout in a delayed manner regardless of age.

Effect of diet composition on acid-base balance in adolescents, young adults and elderly at rest and during exercise.

BACKGROUND: Diets rich in animal protein and cereal grains and deficient in vegetables and fruits may cause low-grade metabolic acidosis, which may impact exercise and health. We hypothesized that (1) a normal-protein diet with high amount of vegetables and fruits (HV) induces more alkaline acid-base balance compared with a high-protein diet with no vegetables and fruits (HP) and (2) diet composition has a greater impact on acid-base balance in the elderly (ELD). SUBJECTS/METHODS: In all, 12-15 (adolescents (ADO)), 25-35 (young adults (YAD)) and 60-75 (ELD)-year-old male and female subjects (n=88) followed a 7-day HV and a 7-day HP in a randomized order and at the end performed incremental cycle ergometer tests. We investigated the effect of diet composition and age on capillary (c-pH) and urine pH (u-pH), strong ion difference (SID), partial pressure of carbon dioxide (pCO2) and total concentration of weak acids (Atot). Linear regression analysis was used to examine the contribution of SID, pCO2 and Atot to c-pH. RESULTS: In YAD and ELD, c-pH (P⩽0.038) and u-pH (P<0.001) were higher at rest after HV compared with HP. During cycling, c-pH was higher (P⩽0.034) after HV compared with HP at submaximal workloads in YAD and at 75% of VO2max (maximal oxygen consumption) in ELD. The contribution of SID, pCO2 and Atot to c-pH varied widely. Gender effects or changes in acid-base balance of ADO were not detected. CONCLUSIONS: A high intake of vegetables and fruits increases blood and u-pH in YAD and ELD. ELD compared with younger persons may be more sensitive for the diet-induced acid-base changes.

Effect of pool length on blood lactate, heart rate, and velocity in swimming.

Exercise testing in water has been used to follow the progression of conditioning during regular training in swimmers. The present study examined the effects of pool length in eleven male swimmers on a set of 5 x 200-m freestyle swims with increasing speed from submaximal to maximal. Mean velocity of swimming, blood lactate and heart rate were examined in both 25-m and 50-m pools. Turning benefit as a marker for turning skill was measured separately by a underwater video system (speed difference between pre- and post-turning) during short all-out swims. Maximum force during swimming was measured in tethered swimming and explosive strength of leg extensor muscles was evaluated by a counter movement jump. The significantly higher (p=0.033 - 0.000) blood lactate values for the 50-m pool as compared to the 25-m pool were found at each point of swimming velocity versus blood lactate curve. The highest post-test lactate level was 7.36 +/- 1.47 mmol x l (-1) in the short course and 8.24 +/- 1.55 mmol x l (-1) (p=0.033) in the long course. The maximum swimming velocity was significantly greater (4.5 %) in the 25-m pool swimming (1.38 +/- 0.11 m x s (-1) vs. 1.32 +/- 0.12 m x s (-1); p=0.000). The heart rate values were significantly (p=0.020 - 0.000) lower in the short course than in the long course at all points of submaximal velocity with a mean difference of 7.3 +/- 0.7 bpm. Heart rate was equal (172 +/- 14 vs. 172 +/- 14 bpm) after the maximum swims in both short and long course. The turning benefit in the short maximum swim was 0.12 +/- 0.05 m x s (-1) (8.1 +/- 3.2 %), correlating positively with the difference in maximal swimming velocity between the short and long-pool swims (r = 0.59; p = 0.029), with the maximum force during tethered swimming (r=0.75; p=0.004) and with the vertical jumping height in the counter movement jump (r=0.55; p=0.039). We conclude that the pool length has a strong effect on blood lactate concentration and heart rate with greater swimming velocity in the short course pool.

Serum amino acid concentrations in aging men and women.

The age and gender related differences in serum amino acid concentrations have been assessed in 72 (23-92 years) medically screened healthy men and women who were divided into three male and three female groups according to age. Free-time physical activity and food intake were analysed from the 5-day diaries. The subjects were instructed to eat according to their normal dietary habits and to avoid any clinical complementary nutritional products or other products that could increase protein or energy intake. The blood samples (5 ml) taken from the antecubital vein after an over-night fast were analysed for their amino acid contents by chromatography. In total nutrient intake of energy (P < 0.001), protein (P < 0.001), alcohol (P < 0.05), water (P < 0.01), sodium (P < 0.001) and fiber P < 0.001) decreased significantly with age. The concentration of total amino acids (P < 0.01), essential amino acids (P < 0.001), non-essential amino acids (P < 0.05) and branched-chain amino acids (P < 0.05) decreased, whereas citrulline (P < 0.001) and cysteine (P < 0.001) were the only amino acids, which increased with aging. In addition, men had significantly higher concentrations than women of essential amino acids (P < 0.001), branched-chain amino acids (P < 0.001), and 10 of the 22 individual amino acids assayed (P < 0.01). Women had significantly higher concentrations of aspartate (P < 0.05), glycine (P < 0.01), serine (P < 0.001) and taurine (P < 0.01) than men. It is concluded that the decrease in serum total amino acid concentration is associated with decreased energy and protein intake with aging and men have higher essential amino acid concentration in serum than women.

Leucine supplementation does not enhance acute strength or running performance but affects serum amino acid concentration.

This study described the effect of leucine supplementation on serum amino acid concentration during two different exercise sessions in competitive male power athletes. The subjects performed a strength exercise session (SES; n = 16; 26 +/- 4 years) or a maximal anaerobic running exercise session (MARE; n = 12; 27 +/- 5 years) until exhaustion twice at a 7-day interval. The randomized subjects consumed drinks containing leucine (100 mg x kg/body weight before and during SES or 200 mg x kg/body weight before MARE) or placebo. Blood specimens taken 10 min before (B) and after (A) the sessions were analyzed for serum amino acids. In SES the concentration of leucine was distinctly higher in the leucine supplemented group than in the placebo group in both B (p < 0.001) and A (p < 0.001) samples. The leucine concentration decreased in placebo but not in the leucine supplemented group following the exercise session. Isoleucine (p = 0.017) and valine (p = 0.006) concentration decreased more in the leucine supplemented group than in placebo in A samples. In MARE the concentration of leucine was higher in the leucine supplemented group than in placebo in both B (p < 0.001) and A (p < 0.001) samples and increased (p < 0.001) in the supplemented group following the session. Isoleucine (p = 0.020) and valine (p = 0.006) concentration decreased in the supplemented group in A samples. There were no differences in a counter movement jump after SES or in the running performance in MARE between the leucine supplemented group and placebo. These findings indicate that consuming leucine before or before and during exercise sessions results in changes in blood amino acid concentration. However, the supplementation does not affect an acute physical performance.