Jens Bangsbo

Recreational football as a health promoting activity: a topical review.

The present review addresses the physiological demands during recreational football training and the effects on central health variables that influence the risk of life‐style diseases of young and middle‐aged men. Recent studies have established that recreational football, carried out as small‐sided games can be characterized as having a high aerobic component with mean heart rates of 80–85% of maximum heart rate, which is similar to values observed for elite football players. In addition, the training includes multiple high‐speed runs, sprints, turns, jumps and tackles, which provide a high impact on muscles and bones. Recreational football training in untrained men results in marked improvements in maximum aerobic power, blood pressure, muscle capillarization and intermittent exercise performance, and those effects are similar to interval training and more pronounced than moderate‐intensity continuous running and strength training. Further, recreational football training enhances fat oxidation during exercise and results in a higher fat loss than interval training and strength training, and results in marked muscle hypertrophy and elevates bone mass, more than interval and continuous running. Taken together, recreational football appears to effectively stimulate musculoskeletal, metabolic and cardiovascular adaptations of importance for health and thereby reduces the risk of developing life‐style diseases.

Activity profile and physiological response to football training for untrained males and females, elderly and youngsters: influence of the number of players.

The present study examined the activity profile, heart rate and metabolic response of small‐sided football games for untrained males (UM, n=26) and females (UF, n=21) and investigated the influence of the number of players (UM: 1v1, 3v3, 7v7; UF: 2v2, 4v4 and 7v7). Moreover, heart rate response to small‐sided games was studied for children aged 9 and 12 years (C9+C12, n=75), as well as homeless (HM, n=15), middle‐aged (MM, n=9) and elderly (EM, n=11) men. During 7v7, muscle glycogen decreased more for UM than UF (28 ± 6 vs 11 ± 5%; P<0.05) and lactate increased more (18.4 ± 3.6 vs 10.8 ± 2.1 mmol kg−1 d.w.; P<0.05). For UM, glycogen decreased in all fiber types and blood lactate, glucose and plasma FFA was elevated (P<0.05). The mean heart rate (HRmean) and time >90% of HRmax ranged from 147 ± 4 (EM) to 162 ± 2 (UM) b.p.m. and 10.8 ± 1.5 (UF) to 47.8 ± 5.8% (EM). Time >90% of HRmax (UM: 16–17%; UF: 8–13%) and time spent with high speed running (4.1–5.1%) was similar for training with 2–14 players, but more high‐intensity runs were performed with few players (UM 1v1: 140 ± 17; UM 7v7: 97 ± 5; P<0.05): Small‐sided games were shown to elucidate high heart rates for all player groups, independently of age, sex, social background and number of players, and a high number of intense actions both for men and women. Thus, small‐sided football games appear to have the potential to create physiological adaptations and improve performance with regular training for a variety of study groups.

Positive performance and health effects of a football training program over 12 weeks can be maintained over a 1-year period with reduced training frequency

We examined whether improvements in the performance and health profile of an intensive 12‐week football intervention could be maintained with a reduced training frequency. Seventeen healthy untrained males completed the study. Ten subjects trained 2.4 times/week for 12 weeks and another 52 weeks with 1.3 sessions/week [football group (FG)] and seven subjects acted as controls [control group (CG)]. For FG, fat mass (3.2 kg) and systolic blood pressure (8 mmHg) were lower (P<0.05) after 64 than 0 weeks, and VO2max (8%) and Yo‐Yo intermittent endurance level 2 test performance (49%) were higher (P<0.05), with no difference between 64 and 12 weeks. After 64 weeks, quadriceps muscle mass (11%), mean fiber area (10%) and citrate synthase activity (18%) were higher (P<0.05) than those at 0 weeks. Leg bone mass (3.5%) and density (2.0%) were higher (P<0.05) after 64 than 0 weeks, but not different between 12 and 0 weeks. Plantar jump force (17–18%), 30‐m sprinting velocity (1.3–3.0%) and muscle glycogen concentration (19–21%) were higher (P<0.05) and blood lactate during submaximal exercise was lower (27–72%, P<0.05) after 64 than after 12 and 0 weeks. The above‐mentioned variables were unaltered for CG. In conclusion, positive adaptations in cardiovascular fitness obtained over 12 weeks of regular recreational football training can be maintained over a 1‐year period with a reduced training frequency, with further development in musculo‐skeletal fitness.

Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation

The effect of oral caffeine ingestion on intense intermittent exercise performance and muscle interstitial ion concentrations was examined. The study consists of two studies (S1 and S2). In S1, 12 subjects completed the Yo-Yo intermittent recovery level 2 (Yo-Yo IR2) test with prior caffeine (6 mg/kg body wt; CAF) or placebo (PLA) intake. In S2, 6 subjects performed one low-intensity (20 W) and three intense (50 W) 3-min (separated by 5 min) one-legged knee-extension exercise bouts with (CAF) and without (CON) prior caffeine supplementation for determination of muscle interstitial K(+) and Na(+) with microdialysis. In S1 Yo-Yo IR2 performance was 16% better (P < 0.05) in CAF compared with PLA. In CAF, plasma K(+) at the end of the Yo-Yo IR2 test was 5.2 ± 0.1 mmol/l with no difference between the trials. Plasma free fatty acids (FFA) were higher (P < 0.05) in CAF than PLA at rest and remained higher (P < 0.05) during exercise. Peak blood glucose (8.0 ± 0.6 vs. 6.2 ± 0.4 mmol/l) and plasma NH(3) (137.2 ± 10.8 vs. 113.4 ± 13.3 μmol/l) were also higher (P < 0.05) in CAF compared with PLA. In S2 interstitial K(+) was 5.5 ± 0.3, 5.7 ± 0.3, 5.8 ± 0.5, and 5.5 ± 0.3 mmol/l at the end of the 20-W and three 50-W periods, respectively, in CAF, which were lower (P < 0.001) than in CON (7.0 ± 0.6, 7.5 ± 0.7, 7.5 ± 0.4, and 7.0 ± 0.6 mmol/l, respectively). No differences in interstitial Na(+) were observed between CAF and CON. In conclusion, caffeine intake enhances fatigue resistance and reduces muscle interstitial K(+) during intense intermittent exercise.

Effect of 2-wk intensified training and inactivity on muscle Na+-K+ pump expression, phospholemman (FXYD1) phosphorylation, and performance in soccer players

The present study examined muscle adaptations and alterations in performance of highly trained soccer players with intensified training or training cessation. Eighteen elite soccer players were, for a 2-wk period, assigned to either a group that performed high-intensity training with a reduction in the amount of training (HI, n = 7), or an inactivity group without training (IN, n = 11). HI improved (P < 0.05) performance of the 4th, 6th, and 10th sprint in a repeated 20-m sprint test, and IN reduced (P < 0.05) performance in the 5th to the 10th sprints after the 2-wk intervention period. In addition, the Yo-Yo intermittent recovery level 2 test performance of IN was lowered from 845 +/- 48 to 654 +/- 30 m. In HI, the protein expression of the Na(+)-K(+) pump alpha(2)-isoform was 15% higher (P < 0.05) after the intervention period, whereas no changes were observed in alpha(1)- and beta(1)-isoform expression. In IN, Na(+)-K(+) pump expression was not changed. In HI, the FXYD1ser68-to-FXYD1 ratio was 27% higher (P < 0.01) after the intervention period, and, in IN, the AB_FXYD1ser68 signal was 18% lower (P < 0.05) after inactivity. The change in FXYD1ser68-to-FXYD1 ratio was correlated (r(2) = 0.35; P < 0.05) with change in performance in repeated sprint test. The present data suggest that short-term intensified training, even for trained soccer players, can increase muscle Na(+)-K(+) pump alpha(2)-isoform expression, and that cessation of training for 2 wk does not affect the expression of Na(+)-K(+) pump isoforms. Resting phosphorylation status of the Na(+)-K(+) pump is changed by training and inactivity and may play a role in performance during repeated, intense exercise.

The effect of passive movement training on angiogenic factors and capillary growth in human skeletal muscle

The effect of a period of passive movement training on angiogenic factors and capillarization in skeletal muscle was examined. Seven young males were subjected to passive training for 90 min, four times per week in a motor‐driven knee extensor device that extended one knee passively at 80 cycles min−1. The other leg was used as control. Muscle biopsies were obtained from m. v. lateralis of both legs before as well as after 2 and 4 weeks of training. After the training period, passive movement and active exercise were performed with both legs, and muscle interstitial fluid was sampled from microdialysis probes in the thigh. After 2 weeks of training there was a 2‐fold higher level of Ki‐67 positive cells, co‐localized with endothelial cells, in the passively trained leg which was paralleled by an increase in the number of capillaries around a fibre (P < 0.05). Capillary density was higher than pre‐training at 4 weeks of training (P < 0.05). The training induced an increase in the mRNA level of endothelial nitric oxide synthase (eNOS), the angiopoietin receptor Tie‐2 and matrix metalloproteinase (MMP)‐9 in the passively trained leg and MMP‐2 and tissue inhibitor of MMP (TIMP)‐1 mRNA were elevated in both legs. Acute passive movement increased (P < 0.05) muscle interstitial vascular endothelial growth factor (VEGF) levels 4‐ to 6‐fold above rest and the proliferative effect, determined in vitro, of the muscle interstitial fluid ∼16‐fold compared to perfusate. The magnitude of increase was similar for active exercise. The results demonstrate that a period of passive movement promotes endothelial cell proliferation and angiogenic factors and initiates capillarization in skeletal muscle.

Long-term musculoskeletal and cardiac health effects of recreational football and running for premenopausal women.

We examined long‐term musculoskeletal and cardiac adaptations elicited by recreational football (FG, n=9) and running (RG, n=10) in untrained premenopausal women in comparison with a control group (CG, n=9). Training was performed for 16 months (∼2 weekly 1‐h sessions). For FG, right and left ventricular end‐diastolic diameters were increased by 24% and 5% (P<0.05), respectively, after 16 months. Right ventricular systolic function measured by tricuspid annular plane systolic excursion (TAPSE) increased (P<0.05) in FG after 4 months and further (P<0.05) after 16 months (15% and 32%, respectively). In RG and CG, cardiac structure, E/A and TAPSE remained unchanged. For FG, whole‐body bone mineral density (BMD) was 2.3% and 1.3% higher (P<0.05) after 16 months, than after 4 and 0 months, respectively, with no changes for RG and CG. FG demonstrated substantial improvements (P<0.05) in fast (27% and 16%) and slow (16% and 17%) eccentric muscle strength and rapid force capacity (Imp30ms: 66% and 65%) after 16 months compared with 4 and 0 months, with RG improving Imp30ms by 64% and 46%. In conclusion, long‐term recreational football improved muscle function, postural balance and BMD in adult women with a potential favorable influence on the risk of falls and fractures. Moreover, football training induced consistent cardiac adaptations, which may have implications for long‐term cardiovascular health.

Performance enhancements and muscular adaptations of a 16‐week recreational football intervention for untrained women

The present study investigated the performance effects and physiological adaptations over 16 weeks of recreational football training and continuous running for healthy untrained premenopausal women in comparison with an inactive control group [Football group (FG): n=21; running group (RG): n=18; CO: n=14]. Two weekly 1‐h training sessions were performed in FG and RG. After 4 and 16 weeks of training VO2max was elevated (P<0.05) by 7% and 15%, respectively, in FG, and by 6% and 10%, respectively, in RG. After 16 weeks, Yo‐Yo intermittent endurance level 2 performance was 33% and 19% better (P<0.05) for FG and 29% and 21% better (P<0.05) for RG than after 4 and 0 weeks, respectively. Peak sprinting speed was 12% higher (21.0 ± 0.6 vs 18.8 ± 0.7 km/h; P<0.05) for FG after the training period, whereas no difference was observed for RG. After 4 weeks citrate synthase (CS) and 3‐hydroxyacyl‐CoA dehydrogenase (HAD) activity was 9% and 8%, respectively, higher (P<0.05) than before training in FG with no further changes during the last 12 weeks. In RG, CS increased (P<0.05) by 12% after 4 weeks and no significant increase was observed for HAD. In FG, the number of capillaries per fiber was 18% higher (P<0.05) after 16 weeks (2.44 ± 0.15 vs 2.07 ± 0.05 cap/fiber), with no significant difference for RG. No differences were observed between 0 and 16 weeks for CO. In conclusion, recreational womens football leads to significant increases in VO2max, performance and muscular adaptations throughout a 16‐week training period. Thus, football can be used as an activity to elevate the physical capacity of untrained women.

Beneficial effects of recreational football on the cardiovascular risk profile in untrained premenopausal women.

The present study examined the cardiovascular health effects of 16 weeks of recreational football training in untrained premenopausal women in comparison with continuous running training. Fifty healthy women were matched and randomized to a football (FG, n=25) or a running (RG, n=25) group and compared with a control group with no physical training (CO, n=15). Training was performed for 1 h twice a week. After 16 weeks, systolic and diastolic blood pressure was reduced (P<0.05) in FG (7±2 and 4±1 mmHg) and systolic blood pressure was lowered (P<0.05) in RG (6±2 mmHg). After 16 weeks, resting heart rate was lowered (P<0.05) by 5±1 bpm both in FG and RG, and maximal oxygen uptake was elevated (P<0.05) by 15% in FG and by 10% in RG (5.0±0.7 and 3.6±0.6 mL/min/kg, respectively). Total fat mass decreased (P<0.05) by 1.4±0.3 kg in FG and by 1.1±0.3 kg in RG. After 16 weeks, pulse pressure wave augmentation index (−0.9±2.5 vs 4.2±2.4%), skeletal muscle capillarization (2.44±0.15 vs 2.07±0.05 cap/fib) and low‐density lipoprotein/high‐density lipoprotein cholesterol ratio were improved (P<0.05) in FG, but not altered in RG. No changes were observed in CO. In conclusion, regular recreational football training has significant favorable effects on the cardiovascular risk profile in untrained premenopausal women and is at the least as efficient as continuous running.

Executive summary: the health and fitness benefits of regular participation in small-sided football games.

The present special issue of Scandinavian Journal of Medicine & Science in Sports deals with health and fitness benefits of regular participation in small‐sided football games. One review article and 13 original articles were the result of a 2‐year multi‐center study in Copenhagen and Zurich and include studies of different age groups analyzed from a physiological, medical, social and psychological perspective. The main groups investigated were middle‐aged, former untrained, healthy men and women who were followed for up to 16 months. In addition, elderly, children and hypertensive patients were studied. A summary and interpretations of the main findings divided into an analysis of the physical demands during training of various groups and the effect of a period of training on performance, muscle adaptations and health profile follow. In addition, social and psychological effects on participation in recreational football are considered, the comparison of football training and endurance running is summarized and the effects of football practice on the elderly and children and youngsters are presented.