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Purpose: Examine the acute hormonal and cytokine responses to free-weight resistance training in trained prepubertal and pubertal male children.

Methods: Prepubertal (n = 21; age 11.4 ± 1.1 years; Tanner I–II) and pubertal male children (n = 20; age 15.8 ± 0.7 years; Tanner III–V) conducted a moderate-intensity free-weight resistance training program to failure with venous blood sampling before (pre), immediately after (post) and during the recovery phase of the program (post-15,-30 min). Growth hormone (GH), insulin-like growth factor-I (IGF-I), cortisol, testosterone, IL-6, and TNF-α were analyzed in serum samples. Biological maturation was assessed according to the stages of the Tanner scale.

Results: There was a significant time-by-group interaction in IGF-I response (p = 0.044; η2 = 0.209) and testosterone (p < 0.001; η2 = 0.508), indicating a greater change in the pubertal group compared to the prepubertal group. Both groups significantly increased post-exercise GH levels (p < 0.05). Only the prepuberal group significantly increased levels of IL-6 at all post-exercise time points (p < 0.05). Both groups showed a significant (p < 0.05) increase in TNF-α levels compared to resting levels.

Conclusion: These data suggest that acute testosterone and IGF-I response following resistance training differ between trained prepubertal and pubertal male children. Moderate-intensity resistance training performed to failure may thus have different effects in trained prepubertal and pubertal male children, which should be considered when giving training advice. Trial registration: Clinical trials number: NCT05022992.

Walking Football (WF) is one type of recreational football increasing in popularity, targeting older adults. Further knowledge on the intensity and physical workload of WF, characteristics of the players, the social context, and reasons for playing WF is needed. Thus, the aim of the study was to characterize the individuals that regularly play WF and their experience of WF, and the physiological characteristics of the sport. Sixty-three players from three clubs taking part in organised WF in Sweden were included. The players participated in up to four WF-games and underwent performance tests and answered a questionnaire. The participants mean age was 70.9 years, ranging from 63 to 85 years with 71% (n = 27) of the men and 68% (n = 13) of the women having a BMI > 25. Fifty-one percent (n = 27) of the players had hypertension, and 73% (n = 39) regularly used prescription drugs due to illness. During WF, the players covered on average 2,409 m (2,509 m for men and 2,205 m for women, p =.001). Expressed in percentage of their age-estimated maximal heart rate, mean heart rate represented 80 ± 9 and 80 ± 8% of max for men, and 78 ± 9 and 79 ± 9% of max for women in the first and second halves, respectively, hence WF can be considered a moderate intensity activity for older adults. The main reason for WF participation was to socialize. WF includes a considerable number of accelerations and decelerations, making it more energetically and mechanically demanding than walking.

The aim of the study was to examine physiological and cardiometabolic effects of 12 weeks of walking football (played 2 × 20 min) in physically inactive older adults. Thirty-three volunteers completed the study (men n = 11, women n = 22) were enrolled with a mean age of 74.0 ± 5.7 years. Baseline tests included blood pressure, waist circumference, body composition, blood samples, balance, estimated VO_2max, mobility, grip strength and vertical jump height. Grip strength was significantly higher at the posttest (32.7 ± 7.8 kg vs. 30.7 ± 7.7 kg (p <.005)), and the walking/turning speed was faster making the time to complete the Timed Up and Go test significant shorter at the posttest (6.07 ± 1.0 s vs. 6.87 ± 1.0 s (p <.001)). Waist circumference was lower at the posttest (91.8 ± 13.3 cm vs. 93.9 ± 13.9 cm (p <.001)). HDL-cholesterol was significantly higher at posttest (2.19 ± 1.36 mmol/L vs. 1.98 ± 0.89 mmol/L (p <.005)). HbA1c significantly decreased posttest (39 ± 1.2 mmol/mol vs. 38 ± 5.8 mmol/mol (p <.028)). Walking football for older adults is associated with positive changes in cardiometabolic and physiological variables.

This study analyzed the impact of performing four consecutive football matches separated by 48-72 hours during a FIFA tournament on physical load, technical performance and plasma markers of redox state, muscle damage and inflammation in elite female players. Forty-eight players from three national teams were evaluated at seven time points: before (baseline) and throughout the tournament (after each match and before two training sessions). Only data from players who played all matches were included in the analyses (N = 13). The players were divided into high-rank (N = 6) and low-rank (N = 7) team players according to FIFA standards. Plasma creatine kinase (CK), C-reactive protein (CRP), total antioxidant status (TAS), and uric acid (UA) were analyzed at the selected time points. Technical performance and physical load were also quantified according to team rank. Players from low-rank teams played significantly more time than high-rank players (85 ± 10 vs 67 ± 15 minutes; P = .02; d = 1.51). Low-rank team players presented higher values in technical performance actions than the high-rank team players, but most of the differences were explained by the longer match time played. UA content differed across the matches, increasing from baseline (F_(4,40)  = 3.90; P = .01) and more in the high-rank team players (F_(1,10)  = 20.46; P = .001), while CRP only differed across the matches (F_(4,36)  = 2.66; P = .05), also increasing from baseline. A large time effect was shown for UA only in the high-rank players (η²_p  = 0.50; P = .02). Four consecutive matches did not result in considerable alterations in plasma stress markers, physical load, and technical performance in elite female football players from distinct rank levels.

We study the developmental and professional activities engaged in by 86 female adult soccer players from the senior national teams of Australia, Canada, England, Sweden, and the United States of America. Players completed the Participation History Questionnaire (PHQ) to elicit the amount and type of activities engaged in across their developmental and professional years, including milestones, soccer-specific activity and engagement in other sport activity. Greater specialisation than diversification characterised their childhood developmental activities, including all players starting in soccer in childhood and accumulating more hours in soccer activity than other sports during this period. However, interindividual variation further characterised these childhood activities, with a proportion of players diversifying into other sports and/or soccer play to a greater or lesser degree during childhood when compared to the other players. The amount of coach-led soccer practice increased for all players across their development culminating in an average of 15-16 h/wk across a 40-week season in early adulthood. In contrast, the amount of engagement in other sports and soccer peer-led play varied between players but generally decreased across adolescence to negligible amounts in late adolescence. Findings are commensurate with the deliberate practice framework and early engagement.