During prolonged
resistance training,
protein supplementation is known to promote morphological changes; however, no previous training studies have tested the effect of
insect protein isolate in a human trial. The aim of this study was to investigate the potential effect of
insect protein as a dietary supplement to increase muscle
hypertrophy and strength gains during prolonged
resistance training in young men. Eighteen healthy young men performed
resistance training four day/week for eight weeks. Subjects were block randomized into two groups consuming either an
insect protein isolate or isocaloric
carbohydrate supplementation within 1 h after training and pre-sleep on training days. Strength and body composition were measured before and after intervention to detect adaptions to the
resistance training. Three-day weighed dietary records were completed before and during intervention. Fat- and bone- free mass (FBFM) improved significantly in both groups (Mean (95% confidence interval (CI))), control group (Con): (2.5 kg (1.5, 3.5) p < 0.01),
protein group (Pro): (2.7 kg (1.6, 3.8) p < 0.01) from pre- to post-. Leg and bench press one repetition maximum (1 RM) improved by Con: (42.0 kg (32.0, 52.0) p < 0.01) and (13.8 kg (10.3, 17.2) p < 0.01), Pro: (36.6 kg (27.3, 45.8) p < 0.01) and (8.1 kg (4.5, 11.8) p < 0.01), respectively. No significant differences in body composition and muscle strength improvements were found between groups. In young healthy men,
insect protein supplementation did not improve adaptations to eight weeks of
resistance training in comparison to
carbohydrate supplementation. A high habitual
protein intake in both Con and Pro may partly explain our observation of no superior effect of
insect protein supplementation.