PMID 36670879

Research
All papers

Adding High-Intensity Interval Training to Classical Resistance Training Does Not Impede the Recovery from Inactivity-Induced Leg Muscle Weakness

Venckunas T, Brazaitis M, Snieckus A, Mickevicius M, Eimantas N, Subocius A, Mickeviciene D, Westerblad H, Kamandulis S

Question

Does adding all-out cycling HIIT to resistance training affect recovery from inactivity-induced leg muscle weakness after 3 weeks of unloading?

Summary

Sixteen recreationally active young men completed 3 weeks of dominant-leg unloading and were then randomized to 3 weeks of resistance training alone or resistance training plus all-out cycling HIIT. Adding eight cycling HIIT sessions did not impair recovery of muscle thickness or maximal voluntary contraction torque, and cycling power improved across the HIIT sessions.

Methodology

  • 16 healthy recreationally active young men after 3 weeks of dominant-leg unloading.
  • 16 participants.
  • Stationary cycling plus machine resistance training.
  • Work intervals: 30 s.
  • Recovery: 4 min.
  • Intensity: All-out cycling at 0.75 Nm/kg body weight.
  • Resistance workout about 40 min; HIIT bout block about 14-23 min depending on 4-6 bouts plus setup.
  • HIIT on non-resistance days during 3-week training; resistance 3 days/week.
  • 3 weeks.
  • Randomized post-unloading training comparison
  • Muscle thickness, Muscle force, and Cycling power were tracked.

Outcomes

MVC torque

MVC torque fell after unloading and fully recovered after training in both groups, with no group difference.

About 11% decrease after unloading; no significant group difference at any time.

Improved

Muscle thickness

Muscle thickness fell after unloading and recovered after training in both groups.

About 6% decrease after unloading; no group difference.

Improved

Cycling power

HIIT cycling power increased across the eight sessions.

+5.1 +/- 1.7% by session 2 and +9.1 +/- 3.0% by last session versus session 1.

Improved

Insights

  • All-out cycling HIIT can be progressed from 4 to 6 bouts over 3 weeks when separated from resistance days.
  • This is not enough evidence to prescribe HIIT after disuse without screening or supervision.

Limitations

  • Small sample
  • Men only
  • Short intervention
  • Artificial unloading model
  • No adverse-event reporting
  • Some missing reliable MVC data

Safety

  • No adverse events or injuries were reported.
  • 20 Hz torque reduction after training suggested residual low-frequency force depression despite 48 h rest.