In order to optimize sports performance, high-level athletes are required to manage conflicting training objectives, which often result in periods of high-volume training. These athletes need to perform heavy resistance training sessions to promote physiological adaptations, which consequently induce fatigue. Yet, they need to minimize fatigue to perform subsequent high-quality training sessions often within the same day. To support these training endeavours, a high-quality dietary regimen and adequate protein consumption is deemed to be an essential component of an athlete's recovery plan, as it has been shown to support muscle recovery and reduce muscle inflammation following exercise. Indeed, current sports nutrition recommendations advocate for the consumption of dietary protein and carbohydrate after exercise to promote tissue repair and replenish muscle energy stores (glycogen). Additionally, previous research has shown how water immersion therapies post-exercise may alleviate fatigue and restore performance. However, little is known about how different temperatures, as well as timing of cold-water immersion can support performance recovery in a population of athletes adhering to contemporary post-exercise nutrition recommendations. The objective of this project is to investigate the effects of timing of cold-water immersion relative to exercise on performance recovery within the same day, as well as to investigate whether cold water immersion augments blood amino acid concentrations after exercise and protein intake.

In the 48-hours prior to testing visits, participants will need to fill out a dietary log 2 days before the first visit and replicate their diet before the second and third visit. Participants will also be asked to adhere to the same exercise routine in order to replicate exercise behaviours for all testing days. Testing sessions will be separated by a minimum of seven days but not more than 30 days. The female participants with a regular menstrual cycle will only be tested during the follicular phase (from day one of menstruation and lasts fourteen days) to ensure a standardized hormone level. Each testing day will begin in the morning. Participants will arrive in the laboratory in an overnight fasted state and begin by ingesting a telematic pill and then consume a standardized carbohydrate rich breakfast drink. Afterwards, the athlete will complete the performance tests, which will include five counter-movement jumps, five drop jump, five squat jumps, one 5-second maximal voluntary isometric contraction (MVIC) of the knee-extensors, eight 1-second maximal voluntary isometric contractions (MVIC) of the knee extensors, five maximal isokinetic contractions at three different angular velocities (60, 180, and 240°/s). Then, they will perform the resistance training protocol, consisting of ten sets on the leg press at 65% 1RM. The 1st and 10th sets will be taken to failure. Sets 2 to 9 will be performed at 10 repetitions each. Between set 1 and set 2, they will perform 30 depth drops. The rest time between sets will be two minutes. Immediately post-training, participants will be asked to repeat the same performance tests. They will then be provided with a protein and carbohydrate drink (25 g of whey protein and 45 g of carbohydrate) that will be consumed within 5 minutes. During the experimental visit, 11 blood samples will be collected relative to the water immersion (T = -120, 0, 15, 30, 45, 60, 90, 120, 180, 240, and 300 min), and subsequently analysed for postprandial plasma amino acid concentration. The consumption of the beverage will be followed by an 10-minute mid-clavicular immersion in either CWI (10°C) that is immediate (CWI\_0), delayed for 3-hours (CWI\_3), or an immediate thermoneutral bath (35°C) (THERM). Following the final blood draw (T = 300 min), the performance tests will be performed one last time to evaluate recovery from the strength training. The participant will be asked to fill out the Short Recovery and Stress Scale (SRSS) that measures recovery and stress across emotional, mental, physical, and overall dimensions using eight items before each testing session. They will also be asked to fill out a visual analogue scale (VAS) regarding subjective appetite sensations at the same time as every blood sample. Furthermore, skin and core body temperatures will be monitored throughout the experiment. At the end of each of the experimental visits, the participants will receive an ad libitum pasta meal to measure energy intake. The participants will be instructed to eat until they are comfortably full within 30 minutes. The amount of food consumed will be recorded to calculate the energy intake of each participant. Participants will also need to complete a questionnaire the 24 and 48 hours after each testing session to assess their level of delayed onset muscle soreness. Following the final testing session, participants will be invited to complete a belief questionnaire, aimed at gauging their perceived effectiveness of the recovery conditions they were subjected to.