Haemoglobin, iron status and lung function of adolescents participating in organised sports in the Finnish Health Promoting Sports Club Study.

OBJECTIVES: To compare laboratory test results and lung function of adolescent organised sports participants (SP) with non-participants (NP). METHODS: In this cross-sectional study, laboratory tests (haemoglobin, iron status), and flow-volume spirometry were performed on SP youths (199 boys, 203 girls) and their NP peers (62 boys, 114 girls) aged 14-17. RESULTS: Haemoglobin concentration <120/130 g/L was found in 5.8% of SP and 5.1% NP (OR 1.20, 95% CI 0.54 to 2.68). Ferritin concentration below 15 µg/L was found in 22.7% of both SP and NP girls. Among boys ferritin <30 µg/L was found in 26.5% of SP and 30.2% of NP (OR 0.76, 95% CI 0.40 to 1.47). Among SP iron supplement use was reported by 3.5% of girls and 1.5% of boys. In flow-volume spirometry with bronchodilation test, 7.0% of SP and 6.4% of NP had asthma-like findings (OR 1.17, 95% CI 0.54 to 2.54); those using asthma medication, that is, 9.8% of SP and 5.2% of NP were excluded from the analysis. CONCLUSIONS: Screening for iron deficiency is recommended for symptomatic persons and persons engaging in sports. Lung function testing is recommended for symptomatic persons and persons participating in sports in which asthma is more prevalent.

Effects of resistance training on expression of IGF-I splice variants in younger and older men.

Insulin-like growth factor-I (IGF-I) and its splice variants Insulin-like growth factor-I isoform Ea (IGF-IEa) and mechano growth factor (MGF) may play an important role in muscular adaptations to resistance training (RT) that may be modulated by ageing. It has been suggested that IGF-I induces cellular responses via AKT8 virus oncogene cellular homolog (Akt) and Extracellular signal-regulated kinase (Erk) signalling pathways. Therefore, resistance exercise-induced changes in skeletal muscle IGF-IEa and MGF messenger ribonucleic acid (mRNA), and MGF, Erk1/2, Akt and p70S6K protein expression were investigated before and after 21 weeks of RT in younger (YM, 20-34 yrs., n = 7) and older men (OM, 51-71 yrs., n = 10). Experimental resistance exercises (RE) of 5 × 10 repetition maximum leg presses were performed pre- and post-RT. Muscle biopsies were obtained before and 48 h after REs, to study the late response to muscle loading. The muscle proteins or mRNAs of interest were not systematically influenced by the REs or RT, except for MGF mRNA expression which was increased (p < .01) following RE before RT in OM. No differences were observed between YM and OM in any variables. This study demonstrated that basal levels or RE-induced responses in skeletal muscle MGF, Erk1/2, Akt and p70S6K protein levels or IGF-IEa and MGF mRNA expression did not differ between YM and OM, nor change systematically due to RT. Thus, ageing appears not to effect expression of the present signalling molecules involved in skeletal muscle hypertrophy.

What Makes a 97-Year-Old Man Cycle 5,000 km a Year?

BACKGROUND: The nature versus nurture debate is one of the oldest issues in the study of longevity, health and successful aging. OBJECTIVE: We present a 97-year-old man (I.K.) as an example of the effects of habitual exercise on the aging process. METHODS: Extensive assessments included medical examinations, interviews, musculoskeletal structure, performance characteristics, cognitive function and gut microbiota composition. RESULTS: I.K. suffers from iatrogenic hypogonadism, prostate cancer, hypothyroidism and a history of deep popliteal thrombosis. Notwithstanding, he cycles up to 5,000 km a year and participates in competitive sports. His musculoskeletal properties, athletic performance, cognitive function and gut microbiota are outstanding. Some traits even exceed those seen in middle-aged men. CONCLUSIONS: His long-term physically and intellectually active lifestyles combined with extensive social interactions have most likely contributed to his exercise capacity, despite his medical history.

Recovery after heavy resistance exercise and skeletal muscle androgen receptor and insulin-like growth factor-I isoform expression in strength trained men.

The effects of heavy resistance exercise on skeletal muscle androgen receptor (AR) protein concentration and mRNAs of AR, insulin-like growth factor-I (IGF)-IEa, and mechano growth factor (MGF) expression were examined from biopsies of vastus lateralis (VL) muscle before and 48 hours after heavy resistance exercise (5 × 10 repetition maximum [RM] leg press and 4 × 10RM squats) in 8 adult strength trained men. The present exercise induced an acute decrease in maximal isometric force and increased serum total testosterone (T) and free testosterone (FT) concentrations. During 2 recovery days, maximal isometric force and subjective perception of physical fitness remained significantly lowered, whereas serum creatine kinase activity, subjective muscle soreness, and muscle swelling (i.e., thickness of VL by ultrasound) were significantly increased compared to pre-exercise values. Subjective perception of physical fitness was followed up to 7 days, and by 6 days postexercise, it was elevated above the pre-exercise level. Basal T and FT concentrations remained unaltered after the exercise. No statistically significant changes were observed in AR protein or mRNA expression, but IGF-IEa (p < 0.05) and MGF (p < 0.05) mRNA expression were increased compared to pre-exercise levels. These findings indicate that IGF-IEa and MGF responses may be related to acute regenerative processes in muscle because of exercise and may contribute to muscular adaptation to resistance exercise. Subjective perception of physical fitness suggests that recovery over a pre-exercise level of the present type of heavy resistance exercise can take approximately 6 days.

Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men.

Signaling pathways sense local and systemic signals and regulate muscle hypertrophy. The effects of whey protein ingestion on acute and long-term signaling responses of resistance exercise are not well known. Previously untrained young men were randomized into protein (n = 9), placebo (n = 9), and control (n = 11) groups. Vastus lateralis (VL) muscle biopsies were taken before and 1 h and 48 h after a leg press of 5 x 10 repetitions [resistance exercise (RE)] and after 21 wk (2 times per week) of resistance training (RT). Protein (15 g of whey) or nonenergetic placebo was ingested before and after a single RE bout and each RE workout throughout the RT. The protein group increased its body mass and VL muscle thickness (measured by ultrasonography) already at week 10.5 (P < 0.05). At week 21, the protein and placebo groups had similarly increased their myofiber size. No changes were observed in the nonexercised controls. However, the phosphorylation of p70(S6K) and ribosomal protein S6 (rpS6) were increased at 1 h post-RE measured by Western blotting, the former being the greatest with protein ingestion. Mammalian target of rapamycin (mTOR) phosphorylation was increased after the RE bout and RT only in the protein group, whereas the protein ingestion prevented the post-RE decrease in phosphorylated eukaryotic initiation factor 4E binding protein 1 (p-4E-BP1). Akt phosphorylation decreased after RT, whereas no change was observed in phosphorylated eukaryotic elongation factor 2. A post-RE decrease in muscle myostatin protein occurred only in the placebo group. The results indicate that resistance exercise rapidly increases mTOR signaling and may decrease myostatin protein expression in muscle and that whey protein increases and prolongs the mTOR signaling response.

A single bout of exercise with high mechanical loading induces the expression of Cyr61/CCN1 and CTGF/CCN2 in human skeletal muscle.

High mechanical loading was hypothesized to induce the expression of angiogenic and/or lymphangiogenic extracellular matrix (ECM) proteins in skeletal muscle. Eight men performed a strenuous exercise protocol, which consisted of 100 unilateral maximal drop jumps followed by submaximal jumping until exhaustion. Muscle biopsies were taken 30 min and 48 h postexercise from the vastus lateralis muscle and analyzed for the following parameters: mRNA and protein expression of ECM-associated CCN proteins [cysteine-rich angiogenic protein 61 (Cyr61)/CCN1, connective tissue growth factor (CTGF)/CCN2], and mRNA expression of vascular endothelial growth factors (VEGFs) and hypoxia-inducible factor-1alpha. The mRNA expression of Cyr61 and CTGF increased 30 min after the exercise (14- and 2.5-fold, respectively; P < 0.001). Cyr61 remained elevated 48 h postexercise (threefold; P < 0.05). The mRNA levels of VEGF-A, VEGF-B, VEGF-C, VEGF-D, or hypoxia-inducible factor-1alpha did not change significantly at either 30 min or 48 h postexercise; however, the variation between subjects increased markedly in VEGF-A and VEGF-B mRNA. Cyr61 protein levels were higher at both 30 min and 48 h after the exercise compared with the control (P < 0.05). Cyr61 and CTGF proteins were localized to muscle fibers and the surrounding ECM by immunohistochemistry. Fast fibers stained more intensively than slow fibers. In conclusion, mechanical loading induces rapid expression of CCN proteins in human skeletal muscle. This may be one of the early mechanisms involved in skeletal muscle remodeling after exercise, since Cyr61 and CTGF regulate the expression of genes involved in angiogenesis and ECM remodeling.