Passive heating following the prematch warm-up in soccer: examining the time-course of changes in muscle temperature and contractile function

The effect of muscle warm-up on voluntary and evoked force-time parameters: A systematic review and meta-analysis with meta-regression

BACKGROUND

While muscle contractility increases with muscle temperature, there is no consensus on the best warm-up protocol to use before resistance training or sports exercise due to the range of possible warm-up and testing combinations available. Therefore, the objective of the current study was to determine the effects of different warm-up types (active, exercise-based vs. passive) on muscle function tested using different activation methods (voluntary vs. evoked) and performance test criteria (maximum force vs. rate-dependent contractile properties), with consideration of warm-up task specificity (specific vs. non-specific), temperature measurement method (muscle vs. skin), baseline temperatures, and subject-specific variables (training status and sex).

METHODS

A systematic search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Cochrane, Embase, and ProQuest. Random-effects meta-analyses and meta-regressions were used to compute the effect sizes (ES) and 95 % confidence intervals (95 %CI) to examine the effects of warm-up type, activation method, performance criterion, subject characteristics, and study design on temperature-related performance enhancement.

RESULTS

The search yielded 1272 articles, of which 33 met the inclusion criteria (n = 921). Increasing temperature positively affected both voluntary (3.7 % ± 1.8 %/°C, ES = 0.28 (95 %CI: 0.14, 0.41)) and evoked (3.2 % ± 1.5 %/°C, ES = 0.65 (95 %CI: 0.29, 1.00)) rate-dependent contractile properties (dynamic, fast-velocity force production, and rate of force development (RFD)) but not maximum force production (voluntary: -0.2 % ± 0.9 %/°C, ES = 0.08 (95 %CI: -0.05, 0.22); evoked: -0.1 % ± 0.8 %/°C, ES = -0.20 (95 %CI: -0.50, 0.10)). Active warm-up did not induce greater enhancements in rate-dependent contractile properties (p = 0.284), maximum force production (p = 0.723), or overall function (pooled, p = 0.093) than passive warm-up. Meta-regressions did not reveal a significant effect of study design, temperature measurement method, warm-up task specificity, training status, or sex on the effect of increasing temperature (p > 0.05).

CONCLUSION

Increasing muscle temperature significantly enhances rate-dependent contractile function (RFD and muscle power) but not maximum force in both evoked and voluntary contractions. In contrast to expectation, no effects of warm-up modality (active vs. passive) or temperature measurement method (muscle vs. skin) were detected, although insufficient data prevented robust sub-group analyses.

Passive heating in sport: context-specific benefits, detriments, and considerations

Exercise and passive heating share some acute physiological responses. These include increases in body temperature, sweat rate, blood flow, heart rate, and redistribution of plasma and blood volume. These responses can vary depending on the heating modality or dose (e.g., temperature, duration, body coverage) and are beneficial to athletes in specific scenarios. These scenarios include being applied to increase muscle or force production, induce rapid weight loss, stimulate thermoregulatory or cardiovascular adaptation, or to accelerate recovery. The rationale being to tailor the specific passive heating protocol to target the desired physiological response. However, some acute responses to passive heating may also be detrimental to sporting outcomes, such as exercising in the heat, having unintended residual negative effects on performance or perceptions of fatigue, or even resulting in hospitalisation if implemented inappropriately. Accordingly, the effects of passive heating should be carefully considered prior to implementation by athletes, coaches, and support staff. Therefore, the purpose of this review is to evaluate the physiological responses to different modes and doses of passive heating and explore the various sport contexts where these effects may either benefit or hinder athletes. Understanding these responses can aid the implementation of passive heating in sport and identify potential recommended heating protocols in each given scenario.

Do Intramuscular Temperature and Fascicle Angle Affect Ultrasound Echo Intensity Values?

PURPOSE

Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle "quality" with physical training, disuse, aging, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate experiments to investigate the effects of muscle temperature and fascicle angle, which are known to influence muscle tissue and sound wave properties and therefore affect EI.

METHODS

In experiment 1 ( n = 16, 28.0 ± 6.6 yr), vastus lateralis (VL) ultrasonographic images were acquired and intramuscular temperature continuously recorded for 15 min after 20 min of heating to 40.4°C ± 0.7°C using a microwave device. In experiment 2 ( n = 17, 30.2 ± 9.8 yr), VL sonographic images were obtained with the knee both fully extended (0°) and flexed to 90° and EI and fascicle angle measured post hoc . Fascicle movement was tracked during the passive knee flexion to ensure that sonographic images were obtained at the same muscle region. Knee flexion reduced muscle thickness, and we therefore reran analyses calculating EI using identical dimensions to minimize this effect.

RESULTS

EI decreased only immediately after the passive heating, and although a moderate, negative correlation was observed between EI and temperature ( rrm = -0.36), the effect of muscle temperature was small ( β = 0.97 (-1.89 to -0.06) per degree Celsius, P = 0.051). Nonetheless, EI increased as fascicle angle decreased, and a large, negative correlation ( rrm = -0.85) was observed; the effect of fascicle angle on EI was large ( β = 3.0 (-3.8 to -2.2) per degree, P < 0.01), and this was maintained when analyses were performed at a constant depth of the region of interest ( β = 3.5 (-4.4 to -2.7) per degree, P < 0.01).

CONCLUSIONS

These findings support the hypothesis that fascicle angle meaningfully affects VL EI but provides weak evidence of a temperature effect in vivo . Thus, acute fascicle angle alterations should be accounted for in studies using EI measurements, and longer-term studies should consider whether changes in EI might be partly explained by a change in fascicle angle.

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.

Mouth rinsing and ingesting salty or bitter solutions does not influence corticomotor excitability or neuromuscular function

PURPOSE

To explore the effect of tasting unpleasant salty or bitter solutions on lower limb corticomotor excitability and neuromuscular function.

METHODS

Nine females and eleven males participated (age: 27 ± 7 years, BMI: 25.3 ± 4.0 kg m^-2). Unpleasant salty (1 M) and bitter (2 mM quinine) solutions were compared to water, sweetened water, and no solution, which functioned as control conditions. In a non-blinded randomized cross-over order, each solution was mouth rinsed (10 s) and ingested before perceptual responses, instantaneous heart rate (a marker of autonomic nervous system activation), quadricep corticomotor excitability (motor-evoked potential amplitude) and neuromuscular function during a maximal voluntary contraction (maximum voluntary force, resting twitch force, voluntary activation, 0-50 ms impulse, 0-100 impulse, 100-200 ms impulse) were measured.

RESULTS

Hedonic value (water: 47 ± 8%, sweet: 23 ± 17%, salt: 71 ± 8%, bitter: 80 ± 10%), taste intensity, unpleasantness and increases in heart rate (no solution: 14 ± 5 bpm, water: 18 ± 5 bpm, sweet: 20 ± 5 bpm, salt: 24 ± 7 bpm, bitter: 23 ± 6 bpm) were significantly higher in the salty and bitter conditions compared to control conditions. Nausea was low in all conditions (< 15%) but was significantly higher in salty and bitter conditions compared to water (water: 3 ± 5%, sweet: 6 ± 13%, salt: 7 ± 9%, bitter: 14 ± 16%). There was no significant difference between conditions in neuromuscular function or corticomotor excitability variables.

CONCLUSION

At rest, unpleasant tastes appear to have no influence on quadricep corticomotor excitability or neuromuscular function. These data question the mechanisms via which unpleasant tastes are proposed to influence exercise performance.

Fatigability of the knee extensors following high- and low-load resistance exercise sessions in trained men

PURPOSE

Fatigability after gym-based resistance exercises with high and low loads has not been well described, thus limiting the translation of exhaustive low-weight prescription into athletic practice. We compared the fatigability and recovery of the knee extensor muscles for up to 1H after sessions that involved either high- or low-load resistance exercises.

METHODS

16 trained men performed two resistance exercise sessions between 5 and 7 days apart. The LIGHT session involved five sets to task failure at 50% of maximal knee-extension strength, whereas the HEAVY session accrued repetitions across seven sets at intensities ≥ 80% maximal knee-extension strength. Measures of quadriceps maximal torque and rate of torque development were measured before, after, and 1H after each exercise session. Muscle activation (electromyography and voluntary activation) and contractility were measured from doublet stimulation of the femoral nerve during and after maximal contractions, respectively.

RESULTS

Greater declines in maximal rate of torque development were observed after the LIGHT compared with the HEAVY session (p < 0.001), with full recovery after 1H. Voluntary activation (100-Hz doublet stimulation) and surface electromyograms were reduced immediately after the HEAVY session only (p < 0.05), with greater declines in quadriceps twitch amplitudes after the LIGHT session (p < 0.01). Voluntary activation (100-Hz doublet stimulation) was reduced at 1H after both the HEAVY and LIGHT sessions (p < 0.05).

CONCLUSIONS

Despite differences in the decreases in muscle activation and contractility after high- and low-load resistance-exercise sessions, recovery of neuromuscular function was essentially complete after 1H of rest for both sessions.

Changes in the quadriceps spinal reflex pathway after repeated sprint cycling are not influenced by ischemic preconditioning

PURPOSE

We examined the effect of ischemic preconditioning (IPC) on changes in muscle force, activation, and the spinal reflex pathway during and after repeated sprint cycling.

METHODS

Eight recreationally active men (high-intensity cardiorespiratory training > 3 times per week, > 6 months) completed two exercise sessions (5 sets of 5 cycling sprints, 150% max W), preceded by either IPC (3 × 5 min leg occlusions at 220 mmHg) or SHAM (3 × 5 min at 20 mmHg). Knee extensor maximal force and rate of force were measured before (PRE), immediately post (POST), 1H, and 24H after cycling. Twitch interpolation and resting potentiated twitches were applied to estimate voluntary activation and muscle contractility, respectively. Quadriceps H-reflex recruitment curves were collected at all time-points using 10 Hz doublet stimulation to allow estimation of H-reflex post-activation depression. Surface electromyograms and tissue oxygenation (via near-infrared spectroscopy) were continuously recorded during cycling.

RESULTS

IPC did not affect any measure of neuromuscular function or performance during cycling. Maximal force and muscle contractility were significantly lower at POST and 1H compared to PRE and 24H by up to 50% (p < 0.01). Maximal force was lower than PRE at 24H by 8.7% (p = 0.028). Voluntary activation and rate of force were unchanged. A rightwards shift was observed for the H-reflex recruitment curve POST, and post-activation depression was higher than all other time-points at 24H (p < 0.05). Muscle activation and oxygenation decreased during cycling.

CONCLUSIONS

IPC has a nominal effect on mechanisms associated with neuromuscular function during and after exercise in healthy populations.

Effect of Passive, Active and Combined Warm up on Lower Limb Muscle Performance and Dynamic Stability in Recreational Sports Players

INTRODUCTION

Warm up is an activity that is done before a sports activity. The warm up can be done actively and passively. The preferred mode is active warm up in athletes. There are inconclusive effects of passive warm up compared with an active warm up on short term muscle performance. The cumulative effect of passive and active warm up on muscle performance and dynamic stability is not known.

AIM

To find out the effects of passive, active and combined warm up on lower limb muscle performance and dynamic stability in recreational sports players.

MATERIALS AND METHODS

A randomized crossover study was done on 19 recreational lower limb dominant sports players. Three different warm ups were included in the study passive, active and combined. Active warm up included series of activities like cycling, leg press, jump squats, squat jumps while passive warm up included application of moist heat for a period of 20 minutes on lower limb muscles. Combined warm up included both passive and active warm up. Six different sequences were made from these three warm ups. Subjects were screened and allotted into different groups based on the six warm up sequences after sequence randomization with 48 hours wash out period. After every warm up session Vertical Jump Test (VJT) and Star Excursion Balance Test (SEBT) was performed and results were recorded. Study duration was one year and six months.

RESULTS

There was no difference noticed in both the outcome measures. Mean and SD values for passive, active and combined warm up are 47.62±9.64, 48.50±10.16 and 48.87±10.70 respectively in Vertical Jump Test (VJT) and 85.43±8.61, 85.17±8.60 and 85.17±8.38 respectively for SEBT. The p-value for mean difference between passive-active, active-combined, combined-passive are 0.67, 1.00, 0.51 respectively, for VJT and 1.00, 1.00, 1.00 respectively for SEBT.

CONCLUSION

All warm ups are equally effective in short term sports performance.

Effects of warm-up on hamstring muscles stiffness: Cycling vs foam rolling

This study investigated the effects of active and/or passive warm-up tasks on the hamstring muscles stiffness through elastography and passive torque measurements. On separate occasions, fourteen males randomly completed four warm-up protocols comprising Control, Cycling, Foam rolling, or Cycling plus Foam rolling (Mixed). The stiffness of the hamstring muscles was assessed through shear wave elastography, along with the passive torque-angle relationship and maximal range of motion (ROM) before, 5, and 30 minutes after each experimental condition. At 5 minutes, Cycling and Mixed decreased shear modulus (-10.3% ± 5.9% and -7.7% ± 8.4%, respectively; P≤.0003, effect size [ES]≥0.24) and passive torque (-7.17% ± 8.6% and -6.2% ± 7.5%, respectively; P≤.051, ES≥0.28), and increased ROM (+2.9% ± 2.9% and +3.2% ± 3.5%, respectively; P≤.001, ES≥0.30); 30 minutes following Mixed, shear modulus (P=.001, ES=0.21) and passive torque (P≤.068, ES≥0.2) were still slightly decreased, while ROM increased (P=.046, ES=0.24). Foam rolling induced "small" immediate short-term decreases in shear modulus (-5.4% ± 5.7% at 5 minutes; P=.05, ES=0.21), without meaningful changes in passive torque or ROM at any time point (P≥.12, ES≤0.23). These results suggest that the combined warm-up elicited no acute superior effects on muscle stiffness compared with cycling, providing evidence for the key role of active warm-up to reduce muscle stiffness. The time between warm-up and competition should be considered when optimizing the effects on muscle stiffness.

Effect of specific exercise-based football injury prevention programmes on the overall injury rate in football: a systematic review and meta-analysis of the FIFA 11 and 11+ programmes

OBJECTIVE

To investigate the effect of FIFA injury prevention programmes in football (FIFA 11 and FIFA 11+).

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials comparing the FIFA injury prevention programmes with a control (no or sham intervention) among football players.

DATA SOURCES

MEDLINE via PubMed, EMBASE via OVID, CINAHL via Ebsco, Web of Science, SportDiscus and Cochrane Central Register of Controlled Trials, from 2004 to 14 March 2016.

RESULTS

6 cluster-randomised controlled trials had assessed the effect of FIFA injury prevention programmes compared with controls on the overall football injury incidence in recreational/subelite football. These studies included 2 specific exercise-based injury prevention programmes: FIFA 11 (2 studies) and FIFA 11+ (4 studies). The primary analysis showed a reduction in the overall injury risk ratio of 0.75 (95% CI 0.57 to 0.98), p=0.04, in favour of the FIFA injury prevention programmes. Secondary analyses revealed that when pooling the 4 studies applying the FIFA 11+ prevention programme, a reduction in the overall injury risk ratio (incidence rate ratio (IRR) 0.61; 95% CI 0.48 to 0.77, p<0.001) was present in favour of the FIFA 11+ prevention programme. No reduction was present when pooling the 2 studies including the FIFA 11 prevention programme (IRR 0.99; 95% CI 0.80 to 1.23, p=0.940).

CONCLUSIONS

An injury-preventing effect of the FIFA injury prevention programmes compared with controls was shown in football. This effect was induced by the FIFA 11+ prevention programme which has a substantial injury-preventing effect by reducing football injuries by 39%, whereas a preventive effect of the FIFA 11 prevention programme could not be documented.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42015024120.

Passive heating following the prematch warm-up in soccer: examining the time-course of changes in muscle temperature and contractile function

This study examined changes in muscle temperature, electrically evoked muscle contractile properties, and voluntary power before and after a soccer specific active warm-up and subsequent rest period. Ten amateur soccer players performed two experimental sessions that involved performance of a modified FIFA 11+ soccer specific warm-up, followed by a 12.5-min rest period where participants were required to wear either normal clothing or a passive electrical heating garment was applied to the upper thigh muscles. Assessments around the warm-up and cool-down included measures of maximal torque, rate of torque development, muscle temperature (Tm), and electrically evoked measures of quadriceps contractile function. Tm was increased after the warm-up by 3.2 ± 0.7°C (P < 0.001). Voluntary and evoked rates of torque development increased after the warm-up between 20% and 30% (P < 0.05), despite declines in both maximal voluntary torque and voluntary activation (P < 0.05). Application of a passive heating garment in the cool-down period after the warm-up did not effect variables measured. While Tm was reduced by 1.4 ± 0.4°C after the rest period (P < 0.001), this value was still higher than pre warm-up levels. Voluntary and evoked rate of torque development remained elevated from pre warm-up levels at the end of the cool-down (P < 0.05). The soccer specific warm-up elevated muscle temperature by 3.2°C and was associated with concomitant increases of between 20% and 30% in voluntary rate of torque development, which seems explained by elevations in rate-dependent measures of intrinsic muscle contractile function. Application of a passive heating garment did not attenuate declines in muscle temperature during a 12.5-min rest period.