An athlete participated in an 8-week training program.
The table shows the physiological adaptations for the athlete at the completion of the training program.
\begin{array} {|l|l|}
\hline
\rule{0pt}{2.5ex}\ \ \ \ \textit{Physiological adaptation}\ \ \rule[-1ex]{0pt}{0pt} & \ \ \ \textit{Results for the athlete}\\
\hline
\rule{0pt}{2.5ex}\text{Resting heart rate}\rule[-1ex]{0pt}{0pt} & \text{Decreased}\\
\hline
\rule{0pt}{2.5ex}\text{Stroke volume}\rule[-1ex]{0pt}{0pt} & \text{Substantially increased}\\
\hline
\rule{0pt}{2.5ex}\text{Cardiac output}\rule[-1ex]{0pt}{0pt} & \text{Increased}\\
\hline
\rule{0pt}{2.5ex}\text{Muscle hypertrophy}\rule[-1ex]{0pt}{0pt} & \text{No significant change}\\
\hline
\rule{0pt}{2.5ex}\text{Fast/slow twitch muscle fibres }\rule[-1ex]{0pt}{0pt} & \text{Increased number of capillaries}\\
\ & \text{in slow twitch muscle fibres}\\
\hline
\end{array}
Which of the following shows the most likely features of the training program?
- Anaerobic interval training for 30 minutes, 3 sessions per week, gradually increasing the work-rest ratio each week
- Aerobic continuous training for 60 minutes, at an intensity of 80% maximum heart rate, progressively increasing the number of sessions each week
- Aerobic circuit training for 30 minutes, at an intensity of 90% maximum heart rate, progressively decreasing the number of sessions each week
- Aerobic interval training for 60 minutes, 4 sessions per week, at an intensity of 60% maximum heart rate, progressively increasing the work-rest ratio within each session