Translational Sports Medicine

Review Article

Characterisation of the Muscle Protein Synthetic Response to Resistance Exercise in Healthy Adults: A Systematic Review and Exploratory Meta-Analysis

Table 1

Main characteristics of eligible studies.


Study	Participants	Muscle sample and control	Contraction	Sets × reps × intensity (%) × rest (min)	MD (CI) % h⁻¹ tracer	Meta-analysed

Biolo et al. [63]	5 men 29 years Untrained	VL Mixed PRE	Isotonic Bilateral Knee extensions	14^‡ × 9^‡ × 72^‡† × 2.5^‡	0–3 h 0.049 [0.020, 0.078] Tracer: [¹³C₆]Phe	Yes

Biolo et al. [8]	5 men 24 years Untrained	VL Mixed PRE	Isotonic Bilateral Knee extensions	14^‡ × 9^‡ × 72^‡† × 2.5^‡	0–3 h 0.062 [0.004, 0.120] Tracer: [¹³C₆]Phe	Yes

Burd [23]	8 men 23 years Untrained	VL Mixed PRE	Eccentric Unilateral Knee extensions	10 × 10 × 120^‡ × 1	24–27 h 0.016 [0.007, 0.025] Tracer: [²H₅]Phe	No

Burd et al. [64]	15 men 21 years Trained	VL Mixed + Myo PRE	Isotonic Unilateral Knee extensions	I: 4 × 5^‡ × 90 × 3 II: 4 × 14^‡ × 30 × 3 III: 4 × 24^‡ × 30 × 3	0–4 h Mixed I: 0.115 [0.096, 0.134] II: 0.051 [0.035, 0.067] III: 0.096 [0.083, 0.109] Myo I: 0.063 [0.045, 0.081] II: 0.022 [0.011, 0.033] III: 0.071 [0.062, 0.083] 24–28 h Mixed I: 0.032 [0.015, 0.049] II: 0.030 [0.019, 0.041] III: 0.053 [0.042, 0.064] Myo I: 0.026 [0.017, 0.035] II: 0.007 [−0.002, 0.016] III: 0.051 [0.042, 0.060] Tracer: [¹³C₆]Phe	Yes: 0–4 h mixed

Dreyer et al. [65]	Untrained I: 9 men 27 years II: 8 women 26 years	VL Mixed PRE	Isotonic Bilateral Knee extensions	I: 10 × 10 × 67 × 3 II: 10 × 10 × 66 × 3	0–2 h I: 0.028 [0.014, 0.042] II: 0.030 [−0.013, 0.073] Tracer: [²H₅]Phe	Yes

Etheridge et al. [24]	7 men 21 years Untrained	VL Myo CL	Isometric Unilateral Knee extensions	6 × 8 × 70 × 2	0–2.5 h 0.071 [0.006, 0.136] Tracer: [¹³C₂]Leu	Yes

Fujita et al. [26]	7 men + 4 women 27 years Untrained	VL Mixed PRE	Isotonic Bilateral Knee extensions	10 × 10 × 70 × 3	During RE −0.019 [−0.033, −0.005] Tracer: [²H₅]Phe	No

Fujita et al. [26]	6 men 32 years Untrained	VL Myo PRE	Isotonic Bilateral Knee extensions	4 × 19^‡ × 20 × 0.5	During RE–3 h 0.005 [−0.018, 0.028] Tracer: [¹³C₆]Phe	Yes

Hansen et al. [66]	10 women 60 years Untrained	VL Myo CL	Isotonic Unilateral Knee extensions	10 × 10 × 75^† × 3	24–26 h −0.008 [−0.019, 0.003] Tracer: [¹³C]Pro	No

Holm et al. [60]	10 men 26 years Untrained	VL Myo PRE	Isotonic Unilateral Knee extensions	I: 10 × 36 × 16 × 0.5 II: 10 × 8 × 70 × 3	0.5–3 h I: 0.035 [0.008, 0.062] II: 0.009 [−0.010, 0.028] 3–5.5 h I: 0.013 [−0.017, 0.043] II: 0.065 [0.035, 0.095] Tracer: [¹³C]Leu	Yes: 0.5–3 h

Hulston et al. [67]	8 men + 1 woman 27 years Untrained	VL Mixed CL	Isotonic Unilateral Knee extensions	4 × 9^‡ × 70 × 3	0–4 h 0.024 [0.010, 0.038] Tracer: [¹³C₆]Phe	Yes

Kim et al. [68]	8 men 25 years I: Untrained II: Trained	VL Mixed + Myo PRE	Isotonic Unilateral Knee extensions	8 × 10 × 80 × 2	12–16 h Mixed I: 0.053 [0.031, 0.075] II: 0.011 [−0.003, 0.025] Myo I: 0.012 [0.009, 0.015] II: 0.012 [0.006, 0.018] Tracer: [¹³C₆]Phe	No

Kumar et al. [69]	24 men Untrained I: 24 years II: 70 years	VL Myo PRE	Isotonic Unilateral Knee extensions	A: 3 × 14 × 40 × 3 B: 6 × 14 × 40 × 3 C: 3 × 8 × 75 × 3 D: 6 × 8 × 75 × 3	0-1 h IA: 0.002 [−0.011, 0.015] IB: 0.021 [−0.005, 0.047] IC: 0.002 [−0.023, 0.027] ID: 0.032 [−0.014, 0.078] IIA: 0.013 [−0.002, 0.028] IIB: 0.042 [0.024, 0.060] IIC: −0.016 [−0.031, −0.001] IID: 0.030 [0.015, 0.045] 1-2 h IA: 0.027 [0.018, 0.036] IB: 0.005 [−0.018, 0.028] IC: 0.059 [0.015, 0.103] ID: 0.082 [0.045, 0.119] IIA: 0.005 [−0.010, 0.020] IIB: 0.052 [0.022, 0.082] IIC: 0.032 [0.009, 0.055] IID: 0.054 [0.004, 0.104] 2–4 h IA: 0.010 [0.001, 0.019] IB: 0.017 [0.008, 0.026] IC: 0.002 [−0.009, 0.013] ID: 0.003 [−0.012, 0.018] IIA: 0.008 [−0.020, 0.036] IIB: 0.015 [−0.008, 0.038] IIC: 0.029 [0.020, 0.038] IID: 0.021 [0.001, 0.041] Tracer: [¹³C₂]Leu	Yes: 0–4 h

Kumar et al. [61]	Untrained I: 25 men 24 years II: 25 men 70 years	VL Myo PRE	Isotonic Unilateral Knee extensions	A: 3 × 27 × 20 × 2 B: 3 × 14 × 40 × 2 C: 3 × 9 × 60 × 2 D: 3 × 8 × 75 × 2 E: 6 × 3 × 90 × 2	1-2 h IA: 0.019 [−0.026, 0.064] IB: 0.026 [−0.009, 0.061] IC: 0.055 [0.046, 0.064] ID: 0.068 [0.029, 0.107] IE: 0.054 [0.026, 0.082] IIA: −0.003 [−0.013, 0.007] IIB: 0.006 [−0.008, 0.020] IIC: 0.028 [0.007, 0.049] IID: 0.027 [0.006, 0.048] IIE: 0.026 [0.009, 0.043] Tracer: [¹³C₂]Leu	Yes

Phillips (1999) [70]	6 men + 6 women I: 25 years, untrained II: 26 years, trained	VL Mixed CL	Eccentric Unilateral Knee extensions	8 × 10 × 120 × 3	0–4 h I: 0.043 [0.031, 0.055] II: 0.023 [0.006, 0.040] Tracer: [²H₅]Phe	Yes

Phillips et al. [17]	4 men + 4 women 23 years Untrained	VL Mixed CL	Eccentric + Concentric Bilateral Knee extensions	8 × 8 × 80 × 3	0–3 h 0.061 [0.046, 0.076] 24–27 h 0.036 [0.021, 0.051] 48–51 h 0.019 [0.006, 0.032] Tracer: [²H₅]Phe	Yes: 0–3 h

Robinson et al. [71]	7 men 59 years Untrained	VL Myo CL	Isotonic Unilateral Knee extensions	3 × 8 × 75^† × 2	0–4 h 0.008 [0.001, 0.015] Tracer: [¹³C₆]Phe	Yes

Sheffield-Moore et al. [62]	12 men Untrained I. 29 years II. 67 years	VL Mixed PRE	Isotonic Bilateral Knee extensions	6 × 8 × 80 × NR	During RE–0.2 h I. 0.000 [−0.008, 0.008] II. 0.044 [0.012, 0.076] 0.2–1 h I. 0.019 [0.007, 0.031] II. 0.013 [−0.010, 0.036] 1–3 h I. 0.030 [0.007, 0.053] II. 0.003 [−0.021, 0.027] Tracer: [²H₅]Phe	Yes: 0.2–3 h

Trappe et al. [72]	8 men 27 years Untrained	SOL Mixed CL	Isotonic Unilateral Plantar flexions	12 × 15 × 70 × 2^‡	0–3 h 0.018 [−0.004, 0.040] Tracer: [²H₅]Phe	No

Trappe et al. [73]	6 men 25 years Untrained	VL Mixed PRE	Eccentric Unilateral Knee extensions	12^‡ × 10 × 120 × 1	26–29 h 0.058 [0.046, 0.070] Tracer: [²H₅]Phe	No

Yang et al. [74]	10 men 71 years Untrained	VL Myo PRE	Isotonic Unilateral Knee extensions	3 × NR × 75^† × 2	0–4 h 0.007 [0.004, 0.010] Tracer: [¹³C₆]Phe	Yes

Data are mean (SD); MD = mean difference; CI = 95% confidence interval; VL = m. Vastus lateralis; SOL = m. soleus; Mixed = mixed muscle; Myo = myofibrillar; Intensity, % concentric 1 RM; ^‡varied, data reported are the bout average; ^†estimated via Epley formula; NR = not reported; PRE = pre-exercise control; CL = contralateral control; Phe = phenylalanine; Leu = leucine; Pro = proline.