The effects of a combined recovery strategy during a match-congested period crossing Ramadan: a repeated measurements crossover study among professional male basketball players

2.1 Study design and setting

The present investigation was carried out using a repeated measurements crossover design, and three professional male basketball teams from the Tunisian first division were chosen, totaling 42 players. The first team used combined recovery (COMB, n = 14), the second team had a 45-minute napping (NAP, n = 14), and the third team served as the active control group (CON, n = 14). During the entire duration of the experimental period, The COMB performed 45-min nap before each training session and game combined with cold-water immersion after training sessions and games. The NAP performed 45-min nap before training sessions and games while the CON continues their regular daily routine with no nap/cold water-immersion control. In terms of the napping procedure, participants went to bed around 13:45 in rooms that were quiet, dimly lighted, and generally between 22 and 25 °C to encourage sleep. Participants had 15 minutes to become used to the space before being invited to take a 45-minute nap. Since this time is linked to a marked decline in alertness and an increase in sensations of drowsiness, napping time began at 14:00. In order to give participants adequate time to prevent sleep inertia, the current study similarly chose 14:00 [25]. A licensed professionals from the staff oversees each room to ensure that everyone takes a 45-minute nap throughout the trial time and reports any instances in which the nap is broken. Five minutes after the match ended, the lower limb (up to the iliac crest) was intermittently submerged five times for two minutes in a cold-water bath at 11 °C. The immersion was followed by a two-minute rest period in ambient air (sitting, room temperature at 20 °C) [24]. Ice was added to the bath at regular intervals to maintain the temperature at 11 + 0.7 °C. The water was continuously circulated by a jacuzzi system to keep warmer layers from accumulating close to the participants’ bodies [24]. The participants were instructed to remain still in the bath. On the other hand, during the study period, which was strictly observed by the research members, CON did not snooze or have any chance to immerse themselves in cold water.

2.2 Study participants

For this investigation, 42 professional male basketball players from three First Division clubs in Tunisia volunteered (Table 1). Prior to the experiment, each of the three teams had around eight hours of practice per week and (13.12 ± 1.21) years of training history. An a priori power calculation (G*Power Version 3.0, University of Dusseldorf, Dusseldorf, NRW, Germany) indicates that a power of 0.80 requires a minimum sample size of 12. Basketball players’ technical and physical skill sets are known to be greatly impacted by their activities on the court, therefore before to the study’s commencement, participants completed a series of tests to ascertain their initial levels of skill and physical fitness [26]. Baseline testing revealed no discernible differences between the groups. Research participants had to meet the subsequent requirements in order to be eligible: (1) participate in at least 90% of the workouts; (2) fast as Islamic religion during the RIF; (3) be in excellent condition (no suffering or serious injuries); and (4) not use drugs, ergogenic aids or other substances. The flow chart of the study design was represented in Fig. 1. The study was done throughout the competitive season and was authorized by the local Clinical Research Ethics Committee of the Higher Institute of Sports and Physical Education of Kef, University of Jendouba, Kef, Tunisia (permission No. 9/2018), with the procedure following the Declaration of Helsinki (World Medical Association, [27]). All individuals gave written informed consent to participate in the study.

Fig. 1.Flow graphic represents the study’s progression through the periods in accordance with the CONSORT declarations. COMB: combined recovery strategy group; NAP: 45-minute napping group; CON: control group.

2.3 Procedures and study training

The present experimentation was carried out in 2021–2022 sport season and spanned four weeks in length. The RIF started in April 2022, and the trial phase lasted until May 2022. Days of fasting lasted 15–16 hours, with exercise sessions taking place between 5:00 and 6:30 PM with temperatures of 25.3 ± 3.4 °C and 43.1 ± 9.8% relative humidity. Both groups played two games per week (on Wednesday and Saturday) and worked out four times a week during the RIF period. Players were completely conversant with every technique prior to starting the trial. Training sessions were conducted at the same time of day to lessen the effect of daily variations. Participants were required to wear the same pair of shoes for each testing session. Each group’s training session began with dynamic stretching, skipping exercises and low-intensity jogging for five minutes. Fundamental basketball movements, specialized techniques, technical principles and fundamental defensive movements were the next topics of technical and tactical drills for the groups. The participants in the research exercised for around 90 minutes per session. Participants were evaluated through the initial and final weeks of the RIF for changes in testosterone (T), cortisol (C), RPE, TQR and wellbeing indices (sleep, tiredness, stress and delayed onset of muscular soreness (DOMS)) as primary objectives. Secondary outcomes from the investigation were dietary intake, body composition and sleep quality (Fig. 2).

Fig. 2.Experimental design. NAP: 45-minute napping group.

2.4 Statistical analysis

Both the mean and the standard deviation (SD) of the data are displayed. The Shapiro-Wilk test (<50) was used to evaluate and validate the data’s normality. To verify if the data were homoscedastic, the Levene test was used. With a one-way analysis of variance (ANOVA), baselines for group differences were calculated. Initially, a 3 (groups: COMB, NAP, CON) × 2 (time: first week of RIF, fourth week of RIF) repeated measures ANOVA was conducted to examine the change (first week to fourth week) of hormonal and psychometric variables. Post-hoc Bonferroni adjusted tests were computed if a statistically significant interaction effect was discovered. Furthermore, partial eta-squared was converted to Cohen’s d in order to calculate effect sizes (ES) from the ANOVA result [34]. Hopkins et al.’s [35] findings led to the classification of ES as trivial (<0.2), small (0.2–0.6), moderate (0.6–1.2), big (1.2–2.0) and very high (2.0–4.0). p < 0.05 was designated as the significant level. SPSS for Windows, version 20.0 (SPSS Inc®., Chicago, IL, USA), was used when performing all statistical analyses.

4.1 The impacts of different recovery interventions on internal load

The study’s weekly load outcomes were greater than those documented in basketball players during RIF conditions, but they were comparable to the workload recorded during the competition period (2400 AU) [3, 4]. The three groups’ RPE scores significantly increased at the end of the RIF, according to our findings. This increase in muscle fatigue, particularly during the congested period, may have contributed to the significant increase in RPE and fatigue sensation. This interpretation is consistent with earlier studies that found more tiredness during the RIF [4, 36, 37]. In addition, the finding of the pre-sent study showed a significant lower RPE value in favor of COMB and NAP compared to the CON and a better value in favor of COMB compared to NAP. Our results are essentially explained by the combined effects of daytime napping and the cold-water immersion. The results of the present investigation were similar with earlier researches that reported a decline in RPE mean values by following 40-min napping. Especially, that nap opportunity may lead to a reduction in sensation of fatigue and give a more recovery chances for players also more physical muscular recovery with sleep before training sessions and official games which consequently lead to a lower RPE values [14, 38, 39].

In addition, several studies reported the beneficial effects of cold-water immersion on fatigue and RPE which was in accordance with the finding of the present study in which the participant reported that the treatment was beneficial for recovery and would improve their subsequent performance [40, 41]. In this context, Xiao et al. [40] reported that post-exercise cold-water immersion reduced RPE immediately, but with no significant effect at 24 and 48 h. Moreover, Halson et al. [41] reported that cold-water immersion enhanced the perception of recovery after a simulated 20-min cycling time-trial compared with a passive rest condition. Although these results suggest that cold-water immersion enhances the perception of recovery after exercise, the potential mechanism responsible for this effect remains to be identified. Concerning the average HR, our results showed a notable decline for all three different groups at the conclusion of RIF compared to the beginning of the experimentation. This decline may be explained by the effect of RIF on biochemical and hormonal. Al Suwaidi et al. [42] justified this decline by linking fasting to catecholamine inhibition and decreased venous return, which lowers sympathetic tone and, in turn, lowers blood pressure, heart rate and cardiac output. Another theory is that taking a sleep lowers stress by lowering maximum heart rate during exercise and cortisol levels [43, 44].

4.2 The impacts of deferent recovery interventions on sleep quality

Adequate nighttime sleep is thought to be essential for effective training, competition and recuperation [45]. The current study’s findings showed that three groups had a substantial negative effect at the conclusion of the RIF, with no group differences reported. The results of this study, which included professional basketball players, were consistent with those previously published by Brini et al. [4]. In a similar vein, Faris et al. [12] noted that sleep deprivation that builds up throughout RIF may cause a disturbance in the sleep-wake cycle, increasing exhaustion and impairing both mental and physical functioning. In the identical vein, Lolli et al. [46] found that Ramadan determined an abrupt reduction in time asleep of ~1 h 30 min in the first period of a night cycle and contributed to additional problems of heterogeneous sleep fragmentation that can impact optimal performance development processes [46]. According to past studies, participants may suffer from partial lack of sleep as a result of their RIF habits, which include waking early and having breakfast before daybreak. The central nervous system’s higher cognitive centers will be severely impacted, which will have an undesirable influence on cognitive process, which has been proposed as the primary cause for performance reductions [37, 47].

4.3 The impacts of different recovery intervention on Body composition

Our findings showed that three groups’ body composition had significantly decreased by the conclusion of the RIF. Our results were in line with other research showing a decline in body composition in athletes, particularly basketball players, during RIF [4, 5, 7]. These differences were mostly caused by changes in sleep habits, physical activity, food consumption, meal frequency and dietary patterns that occurred throughout the RIF for a variety of causes. For athletes who were attempting to sustain their level of physical performance during this demanding and draining period, this was particularly true. Furthermore, the substantial weight loss seen at the conclusion of the RIF in this study may possibly be related to the reduction in total calorie and macronutrient consumption, the decrease in fluid intake [48, 49], and the decrease in glycogen-bound water storage [37]. Given this, it has been proposed that the observed drop in body composition during RIF is due to hypohydration and a reduction in the amount of liquids consumed, with minimal body fat decline [4, 7, 8]. Moreover, our results didn’t report a significant difference between groups. Our results coincide with the findings of Gesteiro et al. [50], how showed that sleep patterns influence body composition, being more related to female body composition as nocturnal and nap sleep were associated with higher fat mass, waist circumference and body shape index, while only short nap times were related to higher waist and hip circumference in males [50].

4.4 The impacts of deferent recovery interventions on DOMS and TQR

When comparing the fourth week of RIF to the beginning, the current study’s findings showed a substantial shift in DOMS and TQR, which were significantly impacted. The results of our study were in line with other research in basketball and team sports, particularly during the RIF [4, 5, 37], which showed that training and games were linked with higher levels of tiredness, DOMS and TQR, as well as higher rates of sickness and injury [38]. Furthermore, a decline in physical function can raise the perception of exertion, cause weariness and DOMS to start earlier, and raise the risk of injuries or sickness [51]. Within the same setting, Davis [52] noted that exhaustion might modify neurotransmitter activity and/or lessen the depletion of muscle glycogen, which could have a deleterious impact on cognition and the execution of motor skills.

Moreover, our results revealed a significant better value in favor of COMB and NAP compared to the CON and a better value in favor of COMB compared to NAP. The findings of the present study could be explained by the combined effects daytime nap opportunity and the cold-water immersion. In this context, Bleakley et al. [53] reported that DOMS commonly results after sports and exercise activity and Cold-water immersion, which involves people immersing themselves in water at temperatures of less than 15 °C, is sometimes used to manage muscle soreness after exercise and to speed up recovery time. In the same context, Halson et al. [41] reported that cold-water immersion enhanced the perception of recovery and there was some evidence that cold-water immersion re-duces muscle soreness at 24, 48, 72 and even at 96 hours after exercise compared with “passive” treatment with limited evidence from four trials indicated that participants considered that cold-water immersion improved recovery/reduced fatigue immediately after wards [53]. Concerning the use of napping strategy, Boukhris et al. [39], reported a significant correlation between recovery state and performances which could support the idea that napping may lead to an improved recovery status for the participants. Addition-ally, Brotherton et al. [54], showed that a 1-h nap positively affected subjective mood and ratings of tiredness and these authors suggested that nap may be related to the reduction of the perceived exertion which support the finding of the present study.

4.5 Deferent recovery intervention effects on T/C ratio

Concerning the hormonal statue of the participant all over the present experimentation, our results revealed a significant change on Testosterone and Cortisol levels at the fourth week in comparison with the beginning of RIF our findings revealed a significant decrease of T/C ratio for the three groups with a significant better value in favor of COMB and NAP compared to the CON and a better value in favor of COMB compared to NAP. The current findings supported the results of previous studies who reported that daytime napping and cold-water immersion might facilitate physiological and perceptual recovery through altering the hormonal milieu [43, 55]. In fact, Botonis et al. [43], reported that daytime nap-ping following a night of total sleep loss affected cortisol secretion significantly during both the nap and post nap periods however longitudinal effects of daytime napping still unclear and deeply depend on the (intensity/duration) of the (training/games). Concerning the cold-water immersion, Leppäluoto et al. [55] reported that plasma adrenocorticotropic hormone (ACTH) and cortisol levels seem to decrease significantly after a short time of regular cold-water exposure, probably due to acclimation or adaptation, suggesting that regular cold-water exposure has little effect on stimulating the pituitary-adrenal cortex axis.

Otherwise, our results were different from those reported by Tabben et al. [56], and Halson et al. [41], who showed no changes in cortisol or testosterone concentrations in response to post-exercise cold-water immersion. However, in those studies they exanimated only cold-water immersion only as a single recovery strategy in addition the nature of practiced sport (Basketball vs. Com-bat), the addition of RIF (additional stress for participants), the differences in training (levels/history), and the sampling methodology maybe a good explanation for these differences.

4.6 Limitation

There are a few constraints to take into account, even if this study provides new data. The exclusion of time-motion variables would have contributed an additional layer of data, such as distance traveled and the average number of sprints and high-intensity runs. Type and number of volunteers may have an impact on the results. A bigger and more varied population would probably provide different results from the same investigation. excluded groups (e.g., control groups without training or sports, groups that did not observe Ramadan, etc.). Furthermore, the quasi-experimental form of this study lacks random assignment, which complicates the identification of a cause-and-effect link. It makes use of pre-existing groupings, which makes it more difficult to determine causes. Moreover, baseline data need to have been obtained before the RIF. In order to close this gap about naps and nocturnal sleep, further research is required. Finally, the season of Ramadan needs to be taken into account. Different results may be drawn from research looking at Ramadan under different weather circumstances.