Table 1.

Characteristics of included studies

Study (country)	Sample size	Age, years	Proportion of males	Inclusion criteria	Exclusion criteria	Intervention, dose, frequency/timing, duration, diluter	Placebo
Crooks et al. 2006 [16] (New Zealand)	BC: 18 PLA: 17	Median (range) BC: males, 46 (35–57),   females, 43 (30–53)	0.48	Pack runs ≥ 1 week, marathon training over last 5 years, age < 60 year	Lactose intolerant, allergy to cows milk, whey-protein supplements, treatment for any diagnosed condition	Oral BC (Immulac, NZMP Ltd, Auckland, New Zealand), 26 g of powdered sachets/day corresponding to 10 g of BC, daily, 12 weeks, chocolate powder with 125 ml water	Skim milk matched for equivalent digestible protein content. Flavours and colours added to match BC
		PLA: males, 48 (36–56)   females, 51 (41–58)
Crooks et al. 2010 [17] (New Zealand)	BC: 12 PLA: 13	Mean ± standard error BC: males, 17 ± 1   females, 20 ± 1	0.57	Participating in training program prior to The Auckland Swimming Championships	Lactose intolerant, allergy to cows milk, whey-protein, immunological-modulating supplements, treatment for any diagnosed condition	Oral BC (Immulac, NZMP Ltd, Auckland, New Zealand), 52 g of powdered sachets/day corresponding to 20 g of BC, 10 g morning & evening, 10 weeks, 125 ml water	Skim milk powder, matched for equivalent protein, fat and carbohydrate content
		PLA: males, 19 ± 1,   females, 18 ± 1
Jones et al. 2014 [14] (Wales)	BC: 25 PLA: 28	Mean ± standard deviation BC: 31 ± 14 PLA: 32 ± 13	1.00	≥3 h moderate-vigorous endurance exercise/week	Smoker, medication or other supplements, infectious illness in 4 weeks prior to study	Oral BC (Neovite, UK, London), 20 g/day, 10 g with morning & evening meal, 12 weeks	Isoenergetic/isomacronutrient PLA as described elsewhere
Shing et al. 2007 [18] (Australia)	BC: 14 PLA: 15	Mean ± standard error BC: 29 ± 1 PLA: 27 ± 2	1.00	Cyclists racing competitively ≥ 2 months, consistent training volumes ≥ 2 months	Dietary supplements 1 month prior to study	Oral BC (Numico Research Australia, South Australia, Australia), 10 g/day, morning, 8 week 1 day, 50 ml water + 100 ml milk	Whey protein (Alacen 80; Fonterra Co-op group Limited, Auckland, New Zealand)
Shing et al. 2013 [19] (Australia)	BC: 4 PLA: 6	Mean ± standard error  BC: 22 ± 3 PLA: 23 ± 2	1.00	Cyclists racing competitively ≥3 months. Consistent training volumes ≥ 2 months	None reported	Oral BC (Numico Research Australia, South Australia, Australia), 10 g/day, morning, 8 weeks and 5 days, 50 ml water + 100 ml milk	Whey protein concentrate (Alacen 80; Fonterra Co-op group Limited, Auckland, New Zealand)

BC bovine colostrum, PLA placebo