Functional Impact of Post-exercise Cooling and Heating on Recovery and Training Adaptations: Application to Resistance, Endurance, and Sprint Exercise

Effects of post-exercise cold-water immersion on performance and perceptive outcomes of competitive adolescent swimmers

PURPOSE

To evaluate the effects of repeated use of cold-water immersion (CWI) during a training week on performance and perceptive outcomes in competitive adolescent swimmers.

METHODS

This randomized-crossover study included 20 athletes, who received each intervention [CWI (14 ± 1 °C), thermoneutral water immersion (TWI) (27 ± 1 °C) as placebo, and passive recovery (PAS)] three times a week between the land-based resistance training and swim training. The interventions were performed in a randomized order with a 1-week wash-out period. We tested athletes before and after each intervention week regarding swim (100 m freestyle sprints) and functional performance (flexibility, upper and lower body power, and shoulder proprioception). We monitored athlete's perceptions (well-being, heaviness, tiredness, discomfort and pain) during testing sessions using a 5-item questionnaire. Athlete preferences regarding the interventions were assessed at the end of the study. We used generalized linear mixed models and generalized estimating equations for continuous and categorical variables, respectively (intervention x time).

RESULTS

We found a time effect for swim performance (p = .01) in which, regardless the intervention, all athletes improved sprint time at post-intervention compared to baseline. There was an intervention effect for pain (p = .04) and tiredness (p = .04), but with no significant post-hoc comparisons. We found no significant effects for other outcomes. All athletes reported a preference for CWI or TWI in relation to PAS.

CONCLUSION

The repeated use of CWI throughout a training week did not impact functional or swim performance outcomes of competitive adolescent swimmers. Perceptive outcomes were also similar across interventions; however, athletes indicated a preference for both CWI and TWI.

Optimal Duration of Cold and Heat Compression for Forearm Muscle Biomechanics in Mixed Martial Arts Athletes: A Comparative Study

BACKGROUND Cold and heat therapies for recovery in sports are commonly used, including in the mixed martial arts (MMA). The Game Ready (GR) device can be used for local monotherapy with either heat or cold and for contrast therapy. This study aimed to compare the effects of duration of cold and heat compression on biomechanical changes in the forearm muscles of 20 healthy mixed martial arts athletes. MATERIAL AND METHODS Twenty MMA volunteers (26.5±4.5 years old) underwent 3 different phases of the GR: (1) stimulation time 10 min (eGR-10, GR experimental group), (2) 10 min (cGR-10, sham control group) and (3) 20 min (eGR-20, GR experimental group). The following outcomes were assessed: muscle tone (T), stiffness (S), flexibility (E), pressure pain threshold (PPT), microvascular response (PU), and maximum isometric strength (Fmax). All measurements were performed before GR (rest) and after GR stimulation (post). RESULTS Both eGR-10 and eGR-20 significantly improved outcomes T (p<0.001), S (p<0.001), E (p=0.001, and p<0.001, respectively), PPT (p<0.001), PU (p<0.001), and Fmax (p<0.001). Notably, eGR-20 exhibited superior improvements in PU, Fmax, and PPT, with larger effect sizes (p<0.001). While eGR-10 demonstrated more pronounced reductions in T and S (p<0.001), these results underscore the potential for tailored GR therapy durations to optimize specific recovery goals for MMA athletes. CONCLUSIONS GR stimulation affects muscle biomechanical changes, pain threshold, muscle strength, and tissue perfusion. The study results suggest that 10 min of GR stimulation is sufficient to achieve changes that can be used to optimize recovery for MMA athletes.

Passive heating-induced changes in muscle contractile function are not further augmented by prolonged exposure in young males experiencing moderate thermal stress

Background: We investigated the impact of 1) passive heating (PH) induced by single and intermittent/prolonged hot-water immersion (HWI) and 2) the duration of PH, on muscle contractile function under the unfatigued state, and during the development of muscle fatigue. Methods: Twelve young males volunteered for this study consisting of two phases: single phase (SP) followed by intermittent/prolonged phase (IPP), with both phases including two conditions (i.e., four trials in total) performed randomly: control passive sitting (CON) and HWI (44-45°C; water up to the waist level). SP-HWI included one continuous 45-min bath (from 15 to 60 min). IPP-HWI included an initial 45-min bath (from 15 to 60 min) followed by eight additional 15-min baths interspaced with 15-min breaks at room temperature between 75 and 300 min. Intramuscular (Tmu; measured in the vastus lateralis muscle) and rectal (Trec) temperatures were determined. Neuromuscular testing (performed in the knee extensors and flexors) was performed at baseline and 60 min later during SP, and at baseline, 60, 90, 150 and 300 min after baseline during IPP. A fatiguing protocol (100 electrical stimulations of the knee extensors) was performed after the last neuromuscular testing of each trial. Results: HWI increased Tmu and Trec to 38°C-38.5°C (p < 0.05) during both SP and IPP. Under the unfatigued state, HWI did not affect electrically induced torques at 20 Hz (P20) and 100 Hz (P100). However, it induced a shift towards a faster contractile profile during both SP and IPP, as evidenced by a decreased P20/P100 ratio (p < 0.05) and an improved muscle relaxation (i.e., reduced half-relaxation time and increased rate of torque relaxation; p < 0.05). Despite a reduced voluntary activation (i.e., -2.63% ± 4.19% after SP-HWI and -5.73% ± 4.31% after IPP-HWI; condition effect: p < 0.001), HWI did not impair maximal isokinetic and isometric contraction torques. During the fatiguing protocol, fatigue index and the changes in muscle contractile properties were larger after HWI than CON conditions (p < 0.05). Finally, none of these parameters were significantly affected by the heating duration. Conclusion: PH induces changes in muscle contractile function which are not augmented by prolonged exposure when thermal stress is moderate.

Hot water immersion: Maintaining core body temperature above 38.5°C mitigates muscle fatigue

PURPOSE

Hot water immersion (HWI) has gained popularity to promote muscle recovery, despite limited data on the optimal heat dose. The purpose of this study was to compare the responses of two exogenous heat strains on core body temperature, hemodynamic adjustments, and key functional markers of muscle recovery following exercise-induced muscle damage (EIMD).

METHODS

Twenty-eight physically active males completed an individually tailored EIMD protocol immediately followed by one of the following recovery interventions: HWI (40°C, HWI40 ), HWI (41°C, HWI41 ) or warm water immersion (36°C, CON36 ). Gastrointestinal temperature (Tgi ), hemodynamic adjustments (cardiac output [CO], mean arterial pressure [MAP], and systemic vascular resistance [SVR]), pre-frontal cortex deoxyhemoglobin (HHb), ECG-derived respiratory frequency, and subjective perceptual measures were tracked throughout immersion. In addition, functional markers of muscle fatigue (maximal concentric peak torque [Tpeak ]) and muscle damage (late-phase rate of force development [RFD100-200 ]) were measured prior to EIMD (pre-), 24 h (post-24 h), and 48 h (post-48 h) post-EIMD.

RESULTS

By the end of immersion, HWI41 led to significantly higher Tgi values than HWI40 (38.8 ± 0.1 vs. 38.0°C ± 0.6°C, p < 0.001). While MAP was well maintained throughout immersion, only HWI41 led to increased (HHb) (+4.2 ± 1.47 μM; p = 0.005) and respiratory frequency (+4.0 ± 1.21 breath.min-1 ; p = 0.032). Only HWI41 mitigated the decline in RFD100-200 at post-24 h (-7.1 ± 31.8%; p = 0.63) and Tpeak at post-48 h (-3.1 ± 4.3%, p = 1).

CONCLUSION

In physically active males, maintaining a core body temperature of ~25 min within the range of 38.5°C-39°C has been found to be effective in improving muscle recovery, while minimizing the risk of excessive physiological heat strain.

Repeated-Sprint Training at 5000-m Simulated Altitude in Preparation for the World Rugby Women's Sevens Series: Too High?

PURPOSE

The objective of this study is to investigate the effectiveness of novel repeated-sprint training in hypoxia (RSH) protocol, likely maximizing hypoxic stimulus (higher than commonly used) while preserving training quality (interset rest in normoxia).

METHODS

Twenty-three world-class female rugby sevens players performed four repeated-sprint training sessions (4 sets of 5 × 5-s cycle sprints-25-s intersprint recovery and 3-min interset rest) under normobaric hypoxia (RSH, exercise and interset rest at FiO 2 of 10.6% and 20.9%, respectively; n = 12) or normoxia (repeated-sprint training in normoxia; exercise and interset rest at FiO 2 of 20.9%; n = 11) during a 9-d training camp before international competition. Repeated-sprint ability (8 × 5-s treadmill sprints-25-s recovery), on-field aerobic capacity, and brachial endothelial function were assessed pre- and postintervention.

RESULTS

Arterial oxygen saturation (pooled data: 87.0% ± 3.1% vs 96.7% ± 2.9%, P < 0.001) and peak and mean power outputs (sets 1 to 4 average decrease: -21.7% ± 7.2% vs -12.0% ± 3.8% and -24.9% ± 8.1% vs -14.9% ± 3.5%; both P < 0.001) were lower in RSH versus repeated-sprint training in normoxia. The cumulated repeated-sprint distance covered significantly increased from pre- to postintervention (+1.9% ± 3.0%, P = 0.019), irrespective of the condition ( P = 0.149). On-field aerobic capacity did not change (all P > 0.45). There was no significant interaction (all P > 0.240) or condition main effect (all P > 0.074) for any brachial artery endothelial function variable. Only peak diameter increased ( P = 0.026), whereas baseline and peak shear stress decreased ( P = 0.014 and 0.019, respectively), from pre- to postintervention.

CONCLUSIONS

In world-class female rugby sevens players, only four additional repeated-sprint sessions before competition improve repeated-sprint ability and brachial endothelial function. However, adding severe hypoxic stress during sets of repeated sprints only did not provide supplementary benefits.

Active recovery vs hot- or cold-water immersion for repeated sprint ability after a strenuous exercise training session in elite skaters

This study compared the acute effects of three recovery methods: active recovery (AR), hot- and cold-water immersion (HWI and CWI, respectively), used between two training sessions in elite athletes. Twelve national-team skaters (7 males, 5 females) completed three trials according to a randomized cross-over study. Fifteen minutes after an exhaustive ice-skating training session, participants underwent 20 min of HWI (41.1 ± 0.5°C), 15 min of CWI (12.1 ± 0.7°C) or 15 min of active recovery (AR). After 1 h 30 min of the first exercise, they performed a repeated-sprint cycling session. Average power output was slightly but significantly higher for AR (767 ± 179 W) and HWI (766 ± 170 W) compared to CWI (738 ± 156 W) (p = 0.026, d = 0.18). No statistical difference was observed between the conditions for both lactatemia and rating of perceived exertion. Furthermore, no significant effect of recovery was observed on the fatigue index calculated from the repeated sprint cycling exercises (p > 0.05). Finally, a positive correlation was found between the average muscle temperature measured during the recoveries and the maximal power output obtained during cycling exercises. In conclusion, the use of CWI in between high-intensity training sessions could slightly impair the performance outcomes compared to AR and HWI. However, studies with larger samples are needed to confirm these results, especially in less trained athletes.

EFFECTS OF FUNCTIONAL STRENGTH TRAINING ON SPRINTERS’ STRENGTH

ABSTRACT Introduction: The exercise of functional strength in a sprinter can play an essential performance gain to propulsion. Functional training can significantly affect the sprinter, preventing injury and making better use of physical training. The sprint interval training method has been widely recognized and applied. Objective: This paper explores the effect of functional strength training by the sprint interval training method on the strength quality of sprinters. Methods: This paper uses random sampling to select 30 male college sprinters as research subjects. The volunteers were divided into two groups according to the performance of the 100-meter speed project: All the essential data of the subjects who passed the T-test were without statistical difference P>0.05. Both groups perform daily training. Functional strength training was added to the experimental group by interval start training with a full 12-week cycle. The strength data of the athletes were measured before and after the experiment, measured, and discussed statistically. Results: The indicators showed significant differences, except for the normal left supine position support test, unchanged by the presented intervention(P<0.01). After the experiment, all indicators were statistically significant compared to the control group (P<0.01). The performance of the groups in the ball exercise, static jump, and vertical jump was significantly improved (P<0.01). Conclusion: Functional strength exercise can improve sprinters’ body control and stability. The sprint interval method can also improve the speed of upward force transmission. This conclusion is significant for formulating the strength training plan designed for sprinters. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

A STUDY ON THE EFFECTIVENESS OF MUSCLE STRENGTH GAIN TRAINING IN RUNNING ATHLETES

ABSTRACT Introduction: Muscle strength training can increase the strength of the phasic muscles, aiding in balance and body stability. Running is a physical-dominant speed sport where strength-speed is two crucial quality in the athletic training of its practitioners. It is believed that training muscle strength at high-intensity intervals can increase athletic speed performance. However, there is no determinant point to determine the peak of this relationship. Objective: The purpose of this study is to examine the effect of high-intensity interval muscular strength training on the physical conditioning of athletes. This paper also examines the relationship between muscular strength training and performance training in sprinters. Methods: Twenty sprinter volunteers were randomly selected as research subjects, divided without discrepancies into control and experimental groups, with ten people each. Mathematical statistics were used to analyze the physiological indicators of the subjects before and after muscle strength training. At the same time, the statistical correlation method was applied to analyze the performance changes of athletes before and after the exercise cycle. Results: After muscle strength training, the athletes in the experimental group were better than those before the training. The data were statistically significant (P<0.05). Conclusion: Muscle strength training can promote the physical conditioning of sprinters. At the same time, the training mode can also improve the athlete’s performance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

INTENSIFICATION OF ABDOMINAL CORE SKILLS IN MUSCULAR STRENGTH TRAINING FOR SPRINTER ATHLETES

ABSTRACT Introduction Running is a speed-based physical activity, and abdominal core strength training is a good technique for athletes. The method of abdominal core strength training consists of training the muscles of the central part of the human body, which also aims to improve the physical coordination of its practitioners. Objective Analyze the effects of abdominal core strength training on athletes’ physical performance and performance in competitions. Methods Twenty sprinters were selected as volunteers and had their EMG signals and muscular endurance of the lower body muscles compared during the experiment. The athletes performed an abdominal core training cycle. The statistical method was used to perform an analysis of the obtained data. These experimental data were adjusted, and significant correlations were discovered. The research results of this paper provide a theoretical basis for formulating the athletes’ training strategies. Results The maximum muscular endurance of male and female sprinters was statistically different (P<0.05). Fitness indicators improved in sprinters after abdominal core strength training. The studies were statistically different (P<0.05). Athletes’ performance improved after abdominal core strength training. The data were statistically significant (P<0.05). Conclusion The physical performance and performance of sprinters are positively correlated with abdominal core strength training. Sprinters should focus on abdominal core strength training in their daily training. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.