Comparison of whey protein and alpha-lactalbumin in muscle pain, pressure pain threshold and mood states following strenuous prolonged running

PURPOSE: To compare the effect of whey protein and alpha-lactalbumin ingestion on muscle pain, pressure pain threshold (PPT) and mood state following prolonged strenuous running. METHODS: 12 apparently healthy, active male subjects (age: 30.4 ± 2.8 yr., height: 172.7 ± 5.6 cm, weight: 66.7 ± 6.5 kg, VO₂max: 58.0 ± 6.9 ml·kg-1·min-1) participated in the double-blind counterbalance crossover study. During the main trial, two treatments were applied CHO + Whey PRO or CA: CHO + Alpha-lactalbumin. Participants ran at 70% VO₂max on a standardized treadmill and recovered for 4 hours. Treatments were ingested every 30 minutes during the first two hours of the recovery period, with the amount of 0.66g/kg/h CHO and 0.34g/kg/h PRO. PPT and pain intensity at the biceps femoris muscle and mood state (evaluated by Brunel Mood Scale, BRUMS-C) were evaluated before exercise (Ex 0), 90 min during exercise (Ex- 90) and at 120 min (Re-120) and 240 min (Re-240) post recovery. RESULTS: Compared with Ex-0, muscle pain was significantly higher at Ex-90 in both trials (CA: 4.79 ± 0.72 vs. 0.46 ± 0.22, P<0.01; CW: 4.58 ± 0.67 vs. 0.45 ± 0.16, P<0.01). No treatment effect was found in the rating of muscle pain (P>0.05). Compared with CW, PPT was significantly higher at Re-120 min in CA trial (CA vs. CW: 31.55 ± 3.09 vs. 26.99 ± 2.32 N/cm²; F=5.223, P=0.033). Vigor was slightly higher following CA ingestion than CW ingestion. (CA vs. CW: 4.08 ± 0.47 vs. 3.16 ± 0.47; F=4.382, P=0.066). CONCLUSIONS: Strenuous prolonged running increases muscle pain. Compared with whey protein, alpha-lactalbumin elevates PPT in muscle and potentially enhances the feeling of vigor during short term exercise recovery