Sprinting is a huge testosterone builder apparently  

 Testosterone, good for telling you where you are weak, metabolism booster for the entire day, even a cognitive booster 

 Yeah my notes prior running are rubbish 

 I love doing HIIT or TABATA on the bike 

 I added HIIT on the bike thanks to you, but I want to add one sprint session a week. 5x30 seconds 

 I could add this in the warmer months. In the winter, I wouldn’t have enough time to go outside with everything going on in the morning 

 How much rest in between ? 

 Yes, lifting (upper), along with sprints have been good for me. 

 Hockey is the best workout on the planet. 
If you can’t skate, join a soccer league. 2nd best. 

 I’m a speed rope fan.