PMID 37425869

Research
All papers

At-Home High-Intensity Interval Training for Individuals with Paraplegia Following Spinal Cord Injury: A Pilot Study

Linde MB, Webb KL, Veith DD, Morkeberg OH, Gill ML, Van Straaten MG, Laskowski ER, Joyner MJ, Beck LA, Zhao KD, Wiggins CC, Garlanger KL

Question

Can a 16-week at-home HIIT program improve physical fitness and be implemented with high adherence, compliance, satisfaction, self-efficacy, and acceptable safety among individuals with paraplegia due to spinal cord injury?

Summary

This pilot clinical trial tested a 16-week at-home arm-ergometer HIIT program in adults with paraplegia from spinal cord injury below T6. Participants trained three times per week using a 24-minute session with six 1-minute high-intensity intervals, 2-minute active recoveries, a 3-minute warmup, and a 3-minute cooldown. The study found high adherence, acceptable high-intensity compliance, infrequent non-serious adverse events, improved peak power output, and lower submaximal cardiac output, but VO2peak did not significantly improve.

Methodology

  • Eight analyzed adults with spinal cord injury below T6 who used manual wheelchairs.
  • 8 participants.
  • Arm cycle ergometer.
  • Work intervals: 1 minute.
  • Recovery: 2 minutes active recovery.
  • Intensity: 80% HRR target, >70% HRR accepted; recovery about 30% HRR.
  • 24 minutes.
  • 3 sessions per week.
  • 16 weeks.
  • Pilot clinical trial with repeated laboratory testing at baseline, 8 weeks, and 16 weeks and at-home monitored HIIT sessions.
  • Peak power output, VO2peak, Submaximal cardiac output, and Training adherence and compliance were tracked.

Outcomes

Peak power output

Peak power output improved by about 26%, from 70 +/- 14 W at baseline to 88 +/- 15 W at week 16.

P=0.027

Improved

Submaximal cardiac output

Submaximal cardiac output decreased by about 17% after 16 weeks, interpreted as improved exercise economy.

P=0.028

Improved

VO2peak

VO2peak increased numerically but did not reach statistical significance.

Baseline 1.52 +/- 0.31 L/min, week 16 1.71 +/- 0.25 L/min, P=0.064

No clear change

Adherence

Participants completed 87 +/- 20% of prescribed sessions, with no significant adherence difference between first and last eight weeks.

Range 38-100%; first vs last eight weeks P=0.369

Improved

Safety

Four non-serious adverse events occurred: two shoulder soreness incidents and two sustained tachycardia incidents; all resolved.

Mixed

Insights

  • For screened adults with SCI below T6, home-based upper-body HIIT can achieve high adherence when equipment and heart-rate feedback are provided.
  • Heart-rate recovery may lag during upper-body HIIT in SCI; a 2-minute recovery at a target of about 30% HRR was often not achieved.
  • Short upper-body intervals can improve peak power output even when VO2peak improvement is not statistically significant.
  • Upper-body HIIT programs for SCI users should include shoulder soreness monitoring and resistance reduction options.

Limitations

  • Small sample
  • No control group
  • Pilot design
  • COVID-19 institutional closures limited complete graded exercise testing data
  • Potential participant motivation bias
  • Study-provided at-home equipment limits generalizability

Safety

  • Two shoulder soreness incidents after training, resolved within a week.
  • Two sustained tachycardia incidents likely related to intervention, resolved within 30 minutes after sessions.
  • One participant missed a week of training due to shoulder soreness.
  • Shoulder pain was addressed with rest and reduced resistance.