Implementing concurrent-training and nutritional strategies in professional football: a complex challenge for coaches and practitioners

Scheduling Concurrent Training 48 versus 72 h after Simulated Match Play: Effects on Neuromuscular Function and Fatigue

INTRODUCTION

Scheduling concurrent training (CT) during the in-season microcycle in field-based team sport is driven by prematch and postmatch recovery. This study examined the neuromuscular function, fatigue, and soreness responses to CT administered 48 h (match day (MD) + 2) versus 72 h (MD + 3) after match.

METHODS

Ten male recreational-level team sport athletes were monitored daily during two 5-d microcycles, which began with a simulated match (Soccer-specific Aerobic Field Test (SAFT90)) and CT performed either 48 or 72 h after match. Maximal voluntary force, quadriceps maximum EMG, voluntary activation, muscle contractile function (evoked twitch responses), muscle soreness, and fatigue were assessed immediately before and after the SAFT90, and every 24 up to 96 h after match. Outcome measures were also assessed immediately after CT. The CT consisted of an intermittent sprint protocol and a lower limb resistance training session separated by 1 h.

RESULTS

Immediately after the SAFT90 in both conditions, maximal voluntary force was below baseline (mean change (Δ), -14.6% ± 10.0%; P = 0.03), recovering 48 h post. Quadriceps contractile function (Δ, -31.5% ± 11.4%; P = 0.003) and voluntary activation (Δ, -8.9 ± 6.2%; P = 0.003) were also hampered after the SAFT90, recovering 24 h post in both conditions. In addition, the SAFT90 elicited elevated levels of fatigue and muscle soreness that recovered 24 h after the SAFT90 before increasing at 72 and 96 h post in the MD + 2 and MD + 3 conditions, respectively.

CONCLUSIONS

Recovery of fatigue was only observed at the end of the microcycle when CT was prescribed on MD + 2. Therefore, CT scheduled early (MD + 2) in the microcycle might avoid compromising forthcoming match preparation.

Acute Neuromuscular Response to Team Sports-specific Running, Resistance, and Concurrent Training: A Cross-over Study

PURPOSE

To examine the changes in muscle contractile function, voluntary activation, and muscle damage following lower limb resistance training (RT), intermittent sprint exercise and concurrent training (CT).

METHODS

Ten male, recreational team sport athletes with a history of RT participated in a randomised cross-over study involving an intermittent sprint protocol (ISP), lower limb RT and CT (ISP and RT separated by 1 h). Prior to (PRE), immediately post (POST), 24 h and 48 h following each exercise condition, quadriceps muscle activation, voluntary activation, muscle contractile function (evoked twitch responses), creatine kinase (CK), muscle soreness and POMS-fatigue were recorded.

RESULTS

Quadriceps contractile function was hampered in all conditions, with a significantly greater decline observed POST RT (58.4 ± 18.0%) and CT (54.8 ± 8.6%) compared to ISP (35.9 ± 10.7%; p < 0.05), recovering at 48 h following all exercise conditions. POMS-fatigue ratings increased at POST in all conditions with CT and ISP eliciting the greatest increase, returning to baseline 48 h following all exercise conditions. Quadriceps muscle soreness remained elevated from PRE at 48 h following all exercise conditions. No changes across time were observed for voluntary activation and quadriceps surface EMG amplitude following any exercise condition. The volume and load lifted in the RT session was unaffected by prior intermittent exercise (ISP) in CT.

CONCLUSION

RT impairs contractile function which is not exacerbated when performed 1 h following the ISP. Contractile function following all exercise conditions displayed the same recovery profile (48 h) despite the post-exercise decrement being smaller following the ISP compared to RT and CT. Prior intermittent sprint exercise does not negatively impact the volume of exercise performed in a lower limb RT session.

Methodological Characteristics, Physiological and Physical Effects, and Future Directions for Combined Training in Soccer: A Systematic Review

Combined training (CT) may combine strength and endurance training within a given time period, but it can also encompass additional protocols consisting of velocity, balance, or mobility as part of the same intervention. These combined approaches have become more common in soccer. This systematic review was conducted to (1) characterize the training protocols used in CT studies in soccer, (2) summarize the main physiological and physical effects of CT on soccer players, and (3) provide future directions for research. Methods: A systematic review of Cochrane Library, PubMed, Scopus, SPORTDiscus, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PICOS were defined as follows: P (soccer players of any age or sex); I (CT combining strength and endurance or sprinting or balance or mobility training); C (the control group (whenever applicable), with or without comparative interventions in addition to usual soccer training); O (acute and/or chronic responses: biochemical, physiological and physical); S (must have at least two groups, either randomized or non-randomized). The database search initially identified 79 titles. From those, eight articles were deemed eligible for the systematic review. Three studies analyzed acute responses to concurrent training, while the remaining five analyzed adaptations to CT. In those tested for acute responses, physiological (hormonal) and physical (strength and power external load, internal load) parameters were observed. Adaptations were mainly focused on physical parameters (strength and power, sprints, jumps, repeated sprint ability, aerobic, change-of-direction), with relatively little focus on physiological parameters (muscle architecture). Short-term responses to CT can affect hormonal responses of testosterone after resistance training with internal and external load. In turn, these responses’ effects on strength and power have produced mixed results, as have adaptations. Specifically, strength and hypertrophy are affected to a lesser extent than speed/power movements. Nevertheless, it is preferable to perform CT before endurance exercises since it is a limiting factor for interference. Volume, intensity, rest between sessions, and athletes’ fitness levels and nutrition dictate the degree of interference.

Fatigue, pain, and the recovery of neuromuscular function after consecutive days of full-body resistance exercise in trained men

PURPOSE

This study measured the self-reported level of fatigue, pain, and neuromuscular function of the knee extensor muscles over a three-day period that included two consecutive days of full-body resistance exercises.

METHODS

10 resistance-trained men performed two consecutive days of full-body resistance exercise. Muscle activation (electromyography and voluntary activation), contractility, and presynaptic inhibition of Ia afferents (homosynaptic and GABA mediated presynaptic inhibition) for the quadriceps were examined from femoral and posterior tibial nerve stimulation.

RESULTS

Fatigue and pain were elevated after Day 1, and were not reduced to pre-exercise levels at the start of Day 2 (p < 0.05). Maximal voluntary torque (- 51.4 Nm, 95% CI = 12.4-90.4 Nm, p = 0.005) and rate of torque development (- 469 Nm.s^-1, 95% CI = 109-829 Nm.s^-1, p = 0.006) were reduced after Day 1, had recovered by Day 2, and did not change after the second training session. The maximal amplitude and rate of rise for the quadriceps twitch were reduced after both training sessions (p < 0.01), with recovery 24 h each session. The maximal amplitude and rate of early muscle activation were reduced after Day 1 (p < 0.01), but no changes were observed for voluntary activation, H-reflex size and shape, or measures of Ia presynaptic inhibition.

CONCLUSION

Resistance exercise in the presence of elevated fatigue and pain from a previous training session does not worsen recovery, or lead to significant alterations in quadriceps neuromuscular function. Reduction in muscle contractility, in the absence of declines in muscle activation, does not lead to decreased voluntary torque.

UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness in healthy, moderately-active men after 9 weeks of training

Background

The importance of concurrent exercise order for improving endurance and resistance adaptations remains unclear, particularly when sessions are performed a few hours apart. We investigated the effects of concurrent training (in alternate orders, separated by ~3 hours) on endurance and resistance training adaptations, compared to resistance-only training.

Materials and methods

Twenty-nine healthy, moderately-active men (mean ± SD; age 24.5 ± 4.7 y; body mass 74.9 ± 10.8 kg; height 179.7 ± 6.5 cm) performed either resistance-only training (RT, n = 9), or same-day concurrent training whereby high-intensity interval training was performed either 3 hours before (HIIT+RT, n = 10) or after resistance training (RT+HIIT, n = 10), for 3 d^.wk^-1 over 9 weeks. Training-induced changes in leg press 1-repetition maximal (1-RM) strength, countermovement jump (CMJ) performance, body composition, peak oxygen uptake (V˙O2peak), aerobic power (W˙peak), and lactate threshold (W˙LT) were assessed before, and after both 5 and 9 weeks of training.

Results

After 9 weeks, all training groups increased leg press 1-RM (~24–28%) and total lean mass (~3-4%), with no clear differences between groups. Both concurrent groups elicited similar small-to-moderate improvements in all markers of aerobic fitness (V˙O2peak ~8–9%; W˙LT ~16-20%; W˙peak ~14-15%). RT improved CMJ displacement (mean ± SD, 5.3 ± 6.3%), velocity (2.2 ± 2.7%), force (absolute: 10.1 ± 10.1%), and power (absolute: 9.8 ± 7.6%; relative: 6.0 ± 6.6%). HIIT+RT elicited comparable improvements in CMJ velocity only (2.2 ± 2.7%). Compared to RT, RT+HIIT attenuated CMJ displacement (mean difference ± 90%CI, -5.1 ± 4.3%), force (absolute: -8.2 ± 7.1%) and power (absolute: -6.0 ± 4.7%). Only RT+HIIT reduced absolute fat mass (mean ± SD, -11.0 ± 11.7%).

Conclusions

In moderately-active males, concurrent training, regardless of the exercise order, presents a viable strategy to improve lower-body maximal strength and total lean mass comparably to resistance-only training, whilst also improving indices of aerobic fitness. However, improvements in CMJ displacement, force, and power were attenuated when RT was performed before HIIT, and as such, exercise order may be an important consideration when designing training programs in which the goal is to improve lower-body power.

Scheduling of training and recovery during the in-season weekly micro-cycle: Insights from team sport practitioners

The aim of this study was to determine the in-season micro-cycle scheduling strategies used in professional team sport with particular reference to the reasoning and perceptions that underpin current practice. An online survey was completed by 35 practitioners from professional collision (C; Australian rules football: n = 9; rugby league: n = 6; rugby union: n = 2) and non-collision (NC; soccer; n = 18) sports. Respondents identified a common 48 h post-match recovery period, with few scheduling training stimuli during this period (NC: range: 0-17%; C: range: 0-47%). The majority (C: 78%; NC: 89%) of resistance training sessions were concurrent in nature, often delivering resistance training in the afternoon following field-based training (C: 72%; NC: 92%). NC practitioners were less satisfied with the maintenance of strength, power and hypertrophy (33-44%) versus C sports (59-76%), reflected by the lower frequency of prescription reported (C: 2.4 ± 0.6; NC: 1.5 ± 0.9; p = .003). Cold water immersion following both matches and daily training was highly prevalent, as was the adoption of self-report tools to monitor recovery. The congested and concurrent nature of training prescription during the micro-cycle, together with the universal adoption of routine cold water immersion warrants further investigation to inform evidence-based prescription and scheduling of training and recovery modalities in professional team sports.