by Clare Kennedy
Level 4 personal trainer UCD, Certified nutritionist with MAC Nutrition
My passion is helping people reach goals they have struggled to achieve. While weight loss and body composition are the most active part of my practice, I also work with clients diagnosed with conditions such as osteoporosis and sarcopenia.
In today’s relentless rhythm of life, the notion of carving out a large chunk of time for exercise can feel like a luxury. Between careers, family commitments, and the ever-present pull of social engagements, the best intentions for fitness often fall by the wayside.
However, it is possible to unlock significant health benefits without needing hours. Shorter 15- or 30-minutes workouts, that are carefully designed to be a super-efficient workout, are a great solution for time-conscious individuals.
Why shorter workouts back a punch
The conventional wisdom has been that only extended periods of exertion yield meaningful results. However, a growing body of scientific evidence is challenging this, promoting the remarkable power that can be packed into shorter bursts of high-intensity exercise.
The science behind shorter workouts (typically lasting 15-30 minutes) delivering tangible benefits is strong:
Metabolic ignition
Even a brief, intense bout of exercise acts as a metabolic spark, igniting your body’s calorie-burning furnace and keeping it stoked for hours afterward. This post-exercise oxygen consumption (EPOC), often referred to as the “afterburn effect,” means you continue to burn calories even after you’ve cooled down.
Efficient fat burning
High-Intensity Interval Training (HIIT), a cornerstone of effective short workouts, strategically alternates between intense bursts of activity and brief recovery periods. This method has been shown to be remarkably efficient at torching fat stores in a fraction of the time compared to steady-state cardiovascular exercise.
Cardiovascular fortification
Don’t equate heart health solely with long runs. Shorter, sharp workouts can effectively challenge and strengthen your cardiovascular system, improving endurance and overall heart function without the need for extended gym sessions.
The consistency advantage
Perhaps the most significant benefit of the shorter workout is its inherent accessibility. By removing the formidable barrier of “not having enough time,” these sessions, typically between 15 and 30 minutes, make consistency far more achievable. And as any fitness enthusiast knows, consistency trumps intensity in the long run.
The science speaks: Brief bursts, big benefits
The emerging science supporting the efficacy of short, intense workouts is robust. For example research from institutions like McMaster University and publications in the Journal of Physiology have demonstrated that brief, high-intensity exercise can elicit physiological adaptations comparable to, and in some cases even exceeding, those achieved through longer, moderate-intensity workouts.
An interesting study published in PLoS One by Gibala et al. (2012) investigated the effects of sprint interval training (SIT) compared to moderate-intensity continuous training (MICT). The researchers found that as little as three 20-second “all-out” cycling sprints interspersed with 2 minutes of low-intensity cycling, performed three times per week for 12 weeks, resulted in similar improvements in insulin sensitivity and cardiorespiratory fitness as 45 minutes of continuous moderate-intensity cycling performed five times per week. This highlights the potential impact of short, intense exercise on key health markers.
While this specific study used very short bursts, it underscores the principle that shorter, higher-intensity workouts can be really effective. Other research has consistently shown that workouts in the 15-30 minute range, incorporating high-intensity intervals, can lead to significant gains in endurance, muscle function, and cardiovascular health.
At Stronger You we have a large library of recorded classes, so that you can select short workouts of 15 or 30 minutes’ length. Whether you do a Functional Resistance, Mobility Hiit, or Pilates class the workouts are carefully planned to optimise your workout and deliver maximum impact.
“Clare’s classes via the on-demand tape option have been life changing for me, both mentally and physically – and I never thought I’d say that about anything…”
Louise, class participant