Intensified training in adolescent female athletes: a crossover study of Greek yogurt effects on indices of recovery

Figures & data

Figure 1. CONSORT flow Diagram.

Table 1. Participants’ physical characteristics, pre- and post-training during each nutritional intervention

	Greek Yogurt		Carbohydrate
	Pre	Post	Pre	Post
Height (cm)	165.9 ± 1.4	165.9 ± 1.4	166.0 ± 1.5	166.0 ± 1.5
Body mass (kg)	59.1 ± 2.1	59.5 ± 2.1	59.3 ± 2.0	59.7 ± 2.1
Body fat (%)	22.2 ± 1.8	22.2 ± 1.5	22.2 ± 1.5	22.4 ± 1.5

Values are mean ± SE.

Table 2. Habitual dietary intake and intake during each nutritional intervention

Condition	Energy intake (kcal)	Carbohydrate intake (g·kg^−1·day^−1)	Protein intake (g·kg^−1·day^−1)	Fat intake (g·kg^−1·day^−1)
Habitual	1622.4 ± 139.2	3.3 ± 0.8	1.1 ± 0.1	1.1 ± 0.1
GY	1892.2 ± 79.7	4.0 ± 0.3	1.9 ± 0.1*	1.0 ± 0.1
CHO	1959.4 ± 122.2	5.2 ± 0.3^†	1.0 ± 0.1	1.0 ± 0.1

Values are mean ± SE; habitual dietary intake assessed by food frequency questionnaire; Dietary intake during the Greek Yogurt (GY) and isocaloric carbohydrate (CHO) intervention conditions, including whole food supplements, assessed using diet record. * indicates significantly greater (p < 0.05) in GY than CHO and habitual. † indicates significantly greater (p < 0.05) in CHO is than GY and habitual.

Table 3. Participant performance data from pre- to post-training during each treatment condition

Variable	Pre	Post	∆ Change	Cohen’s d
Broad Jump Distance (cm) *
GY	175.6 ± 5.4	171.8 ± 5.3	− 3.8 ± 2.1	0.20
CHO	177.7 ± 4.5	174.1 ± 4.0	− 3.6 ± 2.0	0.23
Counter-Movement Jump (cm) *
GY	22.6 ± 1.0	22.0 ± 1.0	− 0.6 ± 0.2	0.18
CHO	22.8 ± 1.0	21.9 ± 1.1	− 0.84 ± 0.3	0.24
10 m Sprint (s)
GY	1.85 ± 0.03	1.89 ± 0.04	0.04 ± 0.04	0.32
CHO	1.88 ± 0.05	1.87 ± 0.03	− 0.01 ± 0.05	0.07
20 m Sprint (s)
GY	3.36 ± 0.05	3.46 ± 0.05	0.10 ± 0.04	0.56
CHO	3.42 ± 0.06	3.44 ± 0.05	0.02 ± 0.05	0.10
505 Right Foot Split (s)
GY	3.06 ± 0.06	3.09 ± 0.04	0.03 ± 0.04	0.17
CHO	3.04 ± 0.05	3.09 ± 0.04	0.05 ± 0.02	0.28
505 Left Foot Split (s)
GY	3.02 ± 0.06	3.07 ± 0.04	0.05 ± 0.04	0.28
CHO	3.03 ± 0.04	3.07 ± 0.04	0.04 ± 0.02	0.29
Beep-Test Distance (m)*
GY	1270.7 ± 70.5	1136.9 ± 50.1	− 133.8 ± 34.4	0.61
CHO	1303.1 ± 72.0	1170.7 ± 47.8	− 132.3 ± 36.6	0.60

Performance data are presented as mean ± SE for pre- and post-training with each nutritional intervention Greek yogurt (GY) and isocaloric carbohydrate (CHO). Δ changes from pre- and post-training are presented as mean ± SE (95% CI). * indicates a significant time effect from pre- to post-training (p < 0.05).

Table 4. Resting levels of biomarkers pre-training

Biomarker	Condition	Mean ± SE	Significance
IL6 (pg·ml^−1)	GY	2.6 ± 0.25	p = 0.86
	CHO	2.6 ± 0.34
TNFα (pg·ml^−1)	GY	4.6 ± 0.47	p = 0.92
	CHO	4.6 ± 0.45
IL10 (pg·ml^−1)	GY	16.7 ± 2.0	p = 0.58
	CHO	17.7 ± 2.3
CRP (pg·ml^−1)	GY	367.3 ± 116.9	p = 0.91
	CHO	355.3 ± 73.5
IGF1 (ng·ml^−1)	GY	346.6 ± 29.4	p = 0.29
	CHO	310.1 ± 35.7
CK (u·L^−1)	GY	66.9 ± 8.46	p = 0.58
	CHO	71.9 ± 7.96

Values are mean ± SE; IL6, interleukin 6; IL10, interleukin 10; TNFα, tumor necrosis factor alpha; CRP, C-reactive protein; IGF-1, insulin-like growth factor-1; CK, creatine kinase.

Figure 2. Changes in plasma concentrations from baseline (mean ± SE) of (a) interleukin 6 (IL6), tumor necrosis factor alpha (TNFα), and interleukin 10 (IL10) and (b) C-reactive protein (CRP), pre- to post-simulated soccer training camp with consumption of Greek Yogurt (GY) or isoenergetic carbohydrates (CHO), in adolescent female soccer players (cytokines, n = 13, CRP n = 11). * indicates a significant time-by-intervention interaction (p = 0.04) where GY showed a greater increase from pre to post than CHO.

Figure 3. Changes in plasma concentrations from baseline (mean ± SE) of (a) creatine kinase (CK) and (b) insulin-like growth factor 1 (IGF-1), pre- to post-simulated soccer training camp with consumption of Greek Yogurt (GY) or isoenergetic carbohydrates (CHO), in adolescent female soccer players (CK n = 13, IGF-1 n = 13).