Performing repeated short Sprint Intervals at supra-maximal intensity will improve general fitness and provide health benefits equal/more than moderate-intensity continuous training (O’Connor & Malone 2019; Vollaard et al. 2017 & Ciconi-Kolski et al. 2013).
.
Recent studies report health-related physical adaptations can occur from very low-volume Interval Sprint training sessions within a total time of only 15 minutes and from as little as 33 minutes of total work effort over 4 weeks. A single supra-maximal sprint can produce rapid and severe physiological responses and be a potent stimulus to physical adaptations linked to improved health outcomes for sedentary, overweight and obese adults. Sprint Intervals positively impact muscle, cardiovascular, respiratory function, blood pressure, insulin sensitivity and body composition (O’Connor & Malone 2019).
.
High intensity interval training (HIIT) refers to work efforts of 90 to 100% with work: recovery ratios of 1:1 or 2:1.
Supra-maximal interval training (SIT) is where the work efforts are pushed to intensities greater than 100% with work: recovery ratios ranging from 1:3 to 1:9 (Ciconi-Kolski et al. 2013).
.
For some people the effect of sprint intervals can include nausea, dizziness and fatigue. Due to the high intensity and associated high perceived rate of exertion, classic sprint training protocols are often considered unsuitable, unsafe, unpractical or intolerable for general populations as an alternative or adjunct to general exercise programs. BUT, sprint intervals can be trained like any exercise protocol and all the variables such as frequency, duration and recovery periods can be modified and progressed for anyone willing to try. Studies show improvements in fitness across all age and health categories from Sprint Interval training.
.
The most common sprint interval training model is the Wingate Test, which involves 3 sessions per week of 5, 30 seconds ‘all out’ bursts of stationary bike cycling separated by 4 minutes of recovery. With warm ups and cool downs this program can take up to 45 minutes to complete. Shorter sprint intervals over fewer bouts with less W:R times have recently shown to provide similar health benefits and are more appealing to some people looking to get the most bang for their exercise buck (Gillen et al 2014; Vollaard et al 2017).
.
Supra-maximal Intensity Training:
i) increases muscle capacity
II) enhances oxygen uptake which allows for greater energy restoration
ii) provides greater enzyme activity which can delay the onset of fatigue during intense exercise, allowing for development and progress.
.
With one of the most commonly cited barriers to regular exercise participation being ‘lack of time’ and overwhelming evidence confirming a ‘one-size-fits-all’ approach to physical activity participation doesn’t work, Sprint Interval training offers an alternate way to exercise. By utilising a ratings system of perceived exertion, intensity, can be individualised and progressed through a training program. An added bonus is the sweat-response to sprint training is generally low, which eliminates the need to shower or change clothes after exercise and as it can be performed anywhere at anytime, from running up stairs or running fast outside, little to no equipment is required.
.
Adults are not alone battling barriers to achieving recommended levels of physical activity. Approximately only 1 in 5 children and adolescents currently meet the daily 60 minute target of physical activity and spend 4-6 hours sedentary. Sprint intervals incorporated into the curriculum are being trialled with a 4 week intervention on adolescents performing 5, 30 second ‘all out’ running sprints, interspersed with 30-second rest intervals, 3 times per week. Improvements reported include greater cardio respiratory fitness and improvements in all other health measures. Sprint intervals could be a way to ensure the health benefits of regular exercise are made available to all students not only those who play and enjoy lots of sporting activities (Martin-Smith 2018).
.
HOW MUCH IS ENOUGH
A growing body of evidence supports that performing fewer and/or shorter sprints does not impair the cardio and physical adaptations associated with Sprint Interval Training. Sprint durations from 30 to 10 seconds reported similar increases to the longer Wingate test version. A 6 week program of 3-weekly 10-minute Sprint sessions involving just two 20-second sprints was enough to elicit improved physiological measures. However it is noted that repeated sprints are required for the training to be effective.
.
For some people, regardless of age, ability or health status, Sprint Intervals are seen as more enjoyable compared with other aerobic activities, endurance exercise and strength training. Participants cite feelings of reward, excitement, and success from sprint training and this becomes their personal motivation to get physically active.
.
doi: 10.1371/journal.pone.0154075
doi.org/10.1123/pes.2018-0155
doi:10.1007/s40279-017-0727
doi:10.3390/sports7040085
Comments