Beef Protein Supplementation in Endurance Athletes

This investigation involves a 10 weeks randomised, balanced, double blind parallel group between-subjects design aimed to analyse the effects of combining exercise and a post exercise nutrition strategy (hydrolysates beef protein, whey protein or a isocaloric only carbohydrate placebo) on training outcomes, body composition and blood markers after a period of regular training and feeding intervention. Participants will be divided in three-treatment groups 1) Hydrolysed meat-protein (Beef); 2) Whey (Whey) and 3) non-protein iso-energetic placebo (CHO).

Once considered eligible for the study, and after an initial familiarisation period and baseline tests, participants will be randomly assigned to one of the intervention groups: Beef; Whey and CHO. Each group will follow a 10-week periodised endurance training intervention combined with one of the three specific supplementation treatments (Beef, Whey or CHO). Measurements of blood, body composition, muscle structure and endurance performance will be determined before and after the training intervention.

Once informed consent and health history have been obtained, after the baseline Assessment (t1), participants will divided into three similar profile groups, matched by body mass, age, sex and performance (Vo2max). 1) The Beef protein group (Beef n=12) that will take 20g of hydrolysates beef protein powder and 250 ml of water 2) The whey group (n=12) will take 20 g of whey intact isolate powder mixed with 250 ml of water 3) the contrast group (CHO n=12) that will take an iso-energetic non-protein, only carbohydrate (20 f of maltodextrin plus 250 ml of water) contrast.

Participants: Thirty six participants, recruited from Kent, Medway University Campus, will take part in the project. After being informed of all risk, discomforts, and benefits involved, participants will sign a written informed consent regarding their participation.

Intervention Familiarization period: Participants will undertake 1 sessions of familiarisation with the testing procedure. A qualified conditioning coach will control and assists participants in order to guarantee a correct understanding of the assessment procedure (Body composition, vo2max test, muscle thickness, etc). All participants will be instructed about the appropriate use of the Rate of Perceived Exertion (6-20) Borg scale and the heart rate monitor to control the load and training intensity during test and training.

Endurance Training: Participants will commit to follow a polarised triphasic endurance-training model. This model contains three intensity zones calculated as low intensity [≥ the first ventilatory threshold (VT1), ~ 70% HRmax]; moderate intensity [between VT1 and respiratory compensation point or ventilatory threshold 2 (VT2), >70 < 90% HRmax]; and high intensity [>VT2, 90% HRmax] (Esteve-Lanao et al., 2007). Participants will train 4 to 6 times per week with a total percentage distribution of 75 to 80% at low intensity; 10% at moderate intensity, and 15 to 10% at high intensity.

Supplementation protocol: Training days: Immediately (<10 min) after com Non-training days: before breakfast.

Supplements and placebo will be provided in powder form and should be mixed with 250 ml of plain water at the moment of consumption. Supplements and placebo will looks and tastes identical.

Thus, a total of one 20g doses will be administered on daily bases. Participants should ingest a total of 70 doses for a total of 10 weeks of study intervention.

Supplement will be provided in 14 days based by a blind researcher after Participants should return back the empty bag of the supplement/placebo consumed during the previous 14 days period.

Inclusion criteria

• regularly trained endurance athletes,
• aged 30 to 60 years old,
• minimum 2 years of experience,
• volunteers,

Exclusion criteria

• any musculoskeletal injuries, metabolic conditions, or diseases;
• use of medications, smoking, and nutritional supplements known to affect physical performance, muscle damage or recovery process (e.g., creatine, whey protein, and amino acids) within 6 weeks prior to the start of the study.